Volume 4 Issue 2 2025 – Journal of Plant Biota

Bioactive Secondary Metabolites of Trigonella foenum-graecum and Ocimum basilicum as Sustainable Sources of Antimicrobial Agents

Anjum Aara

Introduction The rapid emergence of antimicrobial resistance among bacterial and fungal pathogens has become a major global public health concern. The widespread and often indiscriminate use of antibiotics and synthetic antimicrobial agents has accelerated the development of resistant microbial strains, thereby reducing the effectiveness of conventional therapeutic options. Antimicrobial resistance not only increases healthcare costs and treatment failures but also poses a significant threat to food security and agricultural sustainability worldwide [1], the extensive application of synthetic fungicides and pesticides in agriculture has raised concerns regarding environmental contamination, non-target toxicity, and the development of resistant pathogen populations [2]. Medicinal plants have long served as an important source of therapeutic agents and continue to play a crucial role in traditional and modern healthcare systems. Plant-derived bioactive compounds possess diverse pharmacological activities, including antimicrobial, antioxidant, anti-inflammatory, anticancer, and immunomodulatory properties. The growing interest in natural products has encouraged researchers to explore medicinal plants as potential alternatives to synthetic antimicrobial agents [3]. Secondary metabolites such as alkaloids, flavonoids, tannins, terpenoids, saponins, phenolic acids, and essential oils are known to contribute significantly to the antimicrobial potential of medicinal plants. These compounds act through various mechanisms, including disruption of microbial cell membranes, inhibition of nucleic acid synthesis, interference with enzyme activity, and suppression of biofilm formation [4]. Among medicinal plants, Trigonella foenum-graecum L. (fenugreek) has gained considerable attention due to its nutritional and medicinal value. Fenugreek is an annual herb belonging to the family Fabaceae and is widely cultivated in Asia, Africa, and Mediterranean regions. Traditionally, it has been used for the management of diabetes, gastrointestinal disorders, inflammation, and infectious diseases. Phytochemical investigations have revealed the presence of steroidal saponins, alkaloids, flavonoids, polyphenols, and dietary fibers, which are responsible for its diverse biological activities [5]. Several studies have reported that extracts of T. foenum-graecum exhibit antimicrobial effects against a broad spectrum of Gram-positive and Gram-negative bacteria as well as fungal pathogens [6]. Similarly, Ocimum basilicum L. (sweet basil), a member of the family Lamiaceae, is a widely recognized aromatic and medicinal herb. Basil contains a rich array of bioactive constituents, including eugenol, linalool, methyl chavicol, rosmarinic acid, flavonoids, and terpenoids. These compounds have been associated with significant antimicrobial, antioxidant, anti-inflammatory, and insecticidal activities [7]. Essential oils and extracts of O. basilicum have demonstrated inhibitory effects against several pathogenic microorganisms, making the plant a promising candidate for the development of natural antimicrobial formulations [8]. Recent advances in computational biology and molecular modeling have enabled the use of in silico approaches for the rapid screening and evaluation of bioactive compounds. Molecular docking and related computational techniques provide valuable insights into ligand-target interactions, binding affinities, and possible mechanisms of antimicrobial action. These approaches reduce the cost and time associated with traditional drug discovery and facilitate the identification of promising lead compounds from medicinal plants [9]. Despite numerous reports describing the biological activities of T. foenum-graecum and O. basilicum, comprehensive studies integrating phytochemical evaluation, antimicrobial assessment, and computational analysis remain limited. Therefore, the present study was undertaken to investigate the antimicrobial potential of bioactive compounds derived from Trigonella foenum-graecum and Ocimum basilicum using in silico analysis and antimicrobial assays. The study aims to evaluate the inhibitory effects of these plant-derived compounds against selected microbial pathogens and to explore their potential mechanisms of action. The findings may contribute to the development of environmentally friendly and sustainable antimicrobial agents for applications in healthcare, agriculture, and food preservation. MATERIALS AND METHODOLOGY Collection and Preparation of Plant Material Fresh mature leaves of Trigonella foenum-graecum L. and Ocimum basilicum L. were collected from Hyderabad, Telangana, India. The plant materials were authenticated by the Department of Botany, Osmania University, Hyderabad. Mature leaves were selected because they contain higher concentrations of secondary metabolites compared to younger leaves. The collected leaves were thoroughly washed with distilled water to remove dust and debris, air-dried at room temperature under shade conditions, and stored in polyethylene bags at 4°C until further use. 2.2 Extraction and Isolation of Phytochemical Fractions Dried leaf samples were powdered using a mechanical grinder and subjected to extraction using an appropriate organic solvent. The concentrated extracts were further purified by column chromatography for the isolation of bioactive fractions. Column chromatography was performed using silica gel as the stationary phase. The chromatographic column was packed uniformly with silica either by dry-packing or wet-packing techniques. In the dry-packing method, dry silica powder was carefully introduced into the column followed by the addition of the mobile phase. In the wet-packing method, a slurry of silica gel prepared in the mobile phase was gradually added into the column to ensure uniform packing and prevent the formation of air bubbles. The crude plant extract was dissolved in chloroform and carefully loaded onto the top of the silica-packed column. Separation of phytochemical constituents was achieved through isocratic elution using chloroform as the mobile phase. Fractions were collected separately according to their elution pattern. Visible bands were monitored during elution, and colorless fractions were analyzed using thin-layer chromatography (TLC) for confirmation of separation. The collected fractions were concentrated and stored for antimicrobial evaluation. 2.3 Antimicrobial Activity Assay The antimicrobial activity of the isolated fractions was evaluated using the Kirby–Bauer disc diffusion method. This method is widely employed for screening the susceptibility of microorganisms to antimicrobial agents. Preparation of Nutrient Agar Nutrient agar medium was prepared by dissolving nutrient medium and agar in distilled water according to standard laboratory procedures. The medium was sterilized by autoclaving at 121°C under 15 psi pressure for 15 minutes and then poured into sterile Petri dishes under aseptic conditions. Preparation of Microbial Cultures Fresh cultures of selected Gram-positive and Gram-negative bacterial strains were prepared and adjusted to an appropriate turbidity equivalent to standard inoculum density. The bacterial suspension was uniformly spread over the surface of sterile nutrient agar plates using a sterile spreader. Disc Diffusion Assay Sterile paper discs (6 mm diameter) were impregnated with plant extract fractions at a concentration of 20 μg/disc and placed on the inoculated agar plates using sterile forceps. Plates were incubated … Read more

Potential of Large Non-coding RNA (lncRNA) in Plants and Human Specially Neurogenerative and Cancer

Satyesh Chandra Roy

Introduction With the discovery of the structure of DNA by Watson and Crick in 1953, there comes the discovery of the Central Dogma which states that genetic information stored in DNA is transcribed to messenger RNA (mRNA), followed by the formation of protein. . Further research has found the discovery of non-coding RNAs in the period 1950 to 1980s, the non-coding tRNA and rRNA in 1960 , followed by early regulatory non-coding RNA(ncRNA) in 1980 . The publication of Human Genomes in 2001, high – throughput sequencing and the ENCODE project have significantly boosted this research, leading to the characterisation of many ncRNAS. In this way, several ncRNAs have been known, such as micro RNAs (miRNAs), small interfering RNAs (siRNAs), small nuclear RNAs (sn RNAs), small nucleolar RNAs (snoRNAs), small Cajal body-specific RNA (scaRNA), piwi-interacting interacting RNA (piRNA) and Long non-coding RNAs (incRNAs). This scaRNA is a class of small non-coding RNA located in the Cajal body (membrane-less nuclear organelles found in eukaryotic cells ), crucial for small nuclear riboprotein (snRNP) biogenesis. Their functions are to guide the modification of of spliceosomal RNAs (U1, U2, U4, U5 and U12) for the proper functioning of the spliceosome during RNA processing. The piwi- interacting RNAs are small non-coding RNAs of generally 25-33 nucleotides long found in animal cells to form RNA-protein complexes with PIWI- like proteins to silence transposable elements from moving within the genome. PIWI proteins are a family of Argonaute proteins that interact with pi RNA to regulate gene expression. Different types of non-coding RNAs found in different organisms have a great potential in understanding the complexity of the organism and the regulatory functions of these RNAs in many cellular processes, particularly in gene regulation. With the advancement of transcriptome analysis in mammals large number of long transcripts have been know which have no protein-coding capacity and so it is called Long or Large non-coding RNAs (lncRNAs), the potential of which will be discussed below. Large/Long Non-coding RNA (lncRNA) and its Function With the advancement of transcriptome analysis in many organisms, it has been noted that the genomes of mammals and other organisms have produced thousands of long transcripts without any protein-coding capacity . These are called long non-coding RNAs (lncRNAs). It has been noted that about 70% of the mammalian genome is actively transcribed, but only 1-2% of it are protein –coding genes [1]. Large non-coding RNAs (lncRNAs) are generally of more than 200 nucleotides long without any protein-coding capacity but it has been noted that they have functions in gene regulation and disease development. With respect to protein-coding genes , lncRNAs can be intergenic, can be intergenic, antisense or intronic. They are also derived from pseudogenes. About 10,000 pseudogenes were found in the mouse and about 15,000 were identified in the human genome [2, 3]. Pseudogenes are non-functional copies of genes that have lost their protein-coding capacity due to mutations during evolution. They are derived from functional genes and are located near their parent genes. Pseudogenes have similarities with functional genes and they can produce non-coding RNAs on occasion . The mammalian pseudogene Lethe is known as large non- coding RNA (LncRNA) that plays a role in regulating the inflammatory stimuli and can be used as anti-inflammatory therapeutic suggesting the regulatory functions within the genome. But not all pseudogenes are functional but some have regulatory functions. The pseudogene Lethe can inhibit the ability of RelA protein (p65) , encoded from RELA gene, by binding to NF-kB promoters leading to RelA deficiency which can cause chronic muco-cutaneous lesions and susceptibility to TNF-induced apoptosis. lncRNAs can originate from various genomic processes like duplication of protein-coding genes , existing non-coding genes and through retrotransposition, tandem duplications and the insertion of transposable elements. lncRNAs may also originate from nuclear RNA polymerases through transcription and post transcriptional modifications . Five RNA polymerases , such as POL I, POL II, POL III and plant specific POL IV and POL V are transcribing diverse types of lncRNAs involving RNA-directed methylation as well as regulating transposable elements in plants [4]. On the basis of genomic localisation , lncRNAs are classified into three types such as i) Long intergenic non-coding RNAs without any overlapping with other gene ; ii) Intronic Large non-coding RNAs which is localised within the intron of a gene ; and iii) antisense lncRNA which is transcribed from the opposite DNA strand of the protein coding gene. Again some of the lncRNAs of mammals are derived from RNA polymerase II, for this reason those lncRNAs are similar to mRNA (1). There is another functional lncRNA known as XIst that helps in the inactivationof one of the X chromosomes of mammals. Dr. Maite Huarte, a molecular biologist at the University of Navarra in Pamplona, Spain, established the functional importance of lncRNA in cellular pathways and the regulatory functions in gene expression and also in different diseases of human, including cancer. It has been known that Transposable elements (TE) is responsible for providing new transcripts but they have another function of bringing functional elements into lncRNA. During the study of Genomic evolution, it has been noted that 45% to 65% of the genome originated from the parasite genome through the insertion of transposable elements. It has been observed that most of the lncRNAs contain at least one TE and human Endogenous Retrovirus (ERV) . The function of Xist ( X chromosome inactivation) and dosage compensation in mammals, is due to the presence of lncRNA. The sequence study of the Xist region showed that there are several repeat domains, like i) Rep-A originated through insertion of ERVB5; ii) Rep-C and Rep-F from ERVB 4 ; and iii) insertion of transposon. Another interesting finding is that the the number of lncRNA has increased during animal evolution, leading to the idea that there is a role of lncRNA in forming complexity in higher organisms [1]. Function of lncRNA Large ncRNAs have a diverse function in cellular processes like cell proliferation, differentiation, stress responses and apoptosis. … Read more

Influence of Arbuscular Mycorrhizal Fungi on performance of Amarathus viridis cultivated in water-stressed Soil

Henry Anozie
Ogechi Ukoha
Victor Okereke

Introduction Traditional leafy vegetables (TLVs), like Amaranthus, have been vital to rural household food systems in Africa for generations, particularly among low-income populations in tropical regions such as Nigeria [19]. The importance of Amaranthus as a vegetable cannot be overstated. Its leaves and tender shoots are commonly boiled and prepared with modern culinary ingredients and they may also be dried during the dry season for use. Amaranthus is one of the few dicotyledonous plants that exhibit C₄ photosynthetic metabolism, a highly efficient photosynthetic pathway that confers high productivity. This characteristic makes Amaranthus a valuable vegetable crop for enhancing food and nutrition in developing African countries [12]. Water scarcity threatens not only arid and semi-arid regions but also other agricultural productive areas that depend on adequate water availability for successful horticulture. Ongoing climate change is expected to intensify both the frequency and severity of drought events worldwide [17], possibly undermining agricultural success achieved to date. Drought represents one of the most severe abiotic stresses, causing greater reductions in crop productivity than most other stress factors [11]. Limited water availability induces stomatal closure, which restricts CO₂ uptake and later reduces photosynthetic activity and carbon allocation [15]. In addition, water stress adversely affects nutrient availability, particularly phosphorus. Severe drought conditions adversely impact plant physiology, growth, development, and reproduction, leading to substantial yield losses and reduced crop quality. Thus, there is an urgent need to develop strategies that could enhance agricultural resilience and mitigate the adverse effects of water scarcity on crop productivity. Such strategies include increased attention to beneficial soil microorganisms, particularly arbuscular mycorrhizal (AM) fungi. Arbuscular mycorrhizal fungi are ubiquitous soil microorganisms capable of forming symbiotic associations with the majority of terrestrial plants. These fungi provide numerous benefits to their host plants [4]. Beyond improving plant nutritional status, AM fungi enhance plant performance and tolerance to various environmental stresses, especially drought stress. The utilization of AM fungi is considered one of the most effective approaches for increasing plant tolerance to environmental stressors [3]. Previous studies have demonstrated that AM symbiosis significantly enhances plant tolerance to water deficit through improved water and nutrient uptake, modifications in host physiology such as photosynthesis and osmotic adjustment, regulation of phytohormones, and the activation of more efficient antioxidant defense systems [7]. Regrettably, there is still dearth of information on the comparative effect of mycorrhiza inocula on the performance of Amaranthus under varying water-stressed environments. Hence, this study is a necessity. Therefore, the objectives of this study were to: Materials and Methods Study area The experiment was conducted at the Screen house of the Department of Crop and Soil Science, University of Port Harcourt at latitude 4054 N and longitude06055 E with an average temperature of 27 0 C, relatively humidity of 78 % but decreases slightly in dry season and an average rainfall ranging from 2500 – 4000mm per annum [2]. The area has a bimodal rainfall pattern with a long rainy season usually between March and July and a short rainy season from September to early November after a short dry spell in August and a longer period from December to February [1]. Soil Sampling and data collection Samples of soil (0 to 30 cm depth) were taken randomly from the research and teaching farm for sterilization. The soil collected was sterilized at a temperature of 121 oC for 4 hours. Data on plant growth parameters collected at 1-week interval were plant height (cm). Number of leaves. Leaf area (cm) and stem girth (cm). Source of Amaranthus spp The Amaranthus spp used for the experiment was gotten from Rivers State Agricultural Development Programme (ADP), Port Harcourt. Arbuscular mycorrhiza fungi and source The source of the mycorrhiza is from the Department of Microbiology, University of Ibadan. AMF inoculum: pure strains of 3 species of AMF were used for the experiment, namely Glomus. clarium, Gigaspora. gigantea and Glomus. mossea. Design and Treatments The experiment consisted of two factors: three species of mycorrhiza and five irrigation levels, arranged in a Completely Randomized Design (CRD). Amaranth seeds were sown in cell trays and allowed to germinate, after which the seedlings were maintained in the trays for six weeks. Prior to transplanting, pure strains of arbuscular mycorrhizal fungi (AMF) were inoculated into the experimental pots at a rate of 20 g per pot. One amaranth seedling was transplanted into each plastic pot with an internal bottom diameter of 30 cm, an internal top diameter of 30 cm, and a height of 35 cm. The five irrigation treatments consisted of 20% field capacity (0.20 FC), 40% field capacity (0.40 FC), 60% field capacity (0.60 FC), 80% field capacity (0.80 FC), and 100% field capacity (1.00 FC). Irrigation levels were monitored using tensiometers (Irrometer Co., Riverside, California, USA) by measuring soil water potential. One tensiometer was installed in a representative pot for each treatment at a soil depth of 10 cm to guide irrigation scheduling. Irrigation was applied whenever soil water potential reached −20 kPa (centibars), with watering carried out at three-day intervals. Field capacity was determined using the gravimetric method. At field capacity, the volume of water required per pot was 27 cl. Accordingly, irrigation treatments of 0.20 FC, 0.40 FC, 0.60 FC, 0.80 FC, and 1.00 FC corresponded to 5.4 cl, 11 cl, 16 cl, 22 cl, and 27 cl of water per pot, respectively. Agronomics practices Cultural practices were observed throughout the period of the experiment. Weeding was done manually using the handpicking method. Watering was done once at an interval of 3 days in the morning or evening. Collection of Data The following data were collected, number of leaves, plant height, stem girth and leaf area. The first data collections were done two weeks after transplanting (WAT). Thereafter, data were collected at an interval of one week. Laboratory analysis Particles size distribution was done using the hydrometer method as described by [5]. Soil pH was determined in 1:1 (soil: water) ratio using a glass electrode pH meter. Organic carbon was determined by the wet oxidation method [20]. Total … Read more

Manifestation of Endophytes in Pest management: Their existence and mechanism of action

Mir Owais Ahmad¹
Wasim Yousuf¹
Barkat Hussain¹
Tahmeena Mushtaq¹
Swaranjit Singh Pathania¹
Owais Bashir¹
Khalid ferooz²

Introduction Endophytes are microorganisms that inhabit internal plant tissues without causing apparent disease symptoms, and they are increasingly recognized as vital partners in plant ecosystems. Residing in roots, stems, and leaves, these microbes have co-evolved with land plants and developed functional strategies that allow mutual survival, including nutrient exchange and enhanced host fitness (1) (2). Their ability to persist within the plant body, despite chemical and physical defense barriers, reflects sophisticated adaptations that secure their ecological niche (3). Early studies described endophytes as cryptic colonizers of great interest because of their capacity to inhabit plant tissues without triggering visible disease (4). Subsequent research revealed that they comprise phylogenetically diverse microbial groups and engage in complex interactions within the endosphere and rhizosphere (5) (6). Beyond their ecological role, endophytes have been shown to enhance crop productivity, disease resistance, and tolerance to environmental stressors, thereby improving yield stability (7). Their functional versatility includes the production of bioactive metabolites (8) promotion of nutrient acquisition (9), and modulation of plant responses to stress. Endophytic microorganisms not only strengthen plant growth and resilience but also act as a hidden layer of defense against biotic stresses (10) (11). Many of their bioactive compounds, originally linked to disease resistance or stress tolerance, are now recognized to influence herbivorous insects as well (12). This dual function has drawn attention to their role as entomopathogens, offering a natural and environmentally compatible approach to pest suppression. Thus, endophytes emerge not only as plant growth promoters but also as promising allies in integrated pest management. The plentitude of pest dynamics can inflict substantial losses, with global yield reductions estimated at around 15 % in major crops (13). Managing these pests once they exceed the economic threshold requires approaches that are both effective and environmentally sound. In this context, endophytic microorganisms are gaining attention by offering protection through the production of secondary metabolites, direct entomopathogenic activity, and other modes of action. This review comprises current understanding of such interactions, emphasizing their potential applications in sustainable crop protection. Growth-promoting factors released by endophytes Endophytic microorganisms are increasingly recognized not only for their defensive role against pests and pathogens but also for their capacity to enhance plant growth and vigor (Fig. 1). These benefits arise through multiple mechanisms, including nutrient mobilization, modulation of plant hormones, and improvement of stress tolerance, siderophore production, osmolyte production and carbon modulation etc. Nutrient Acquisition and Mobilization Biological Nitrogen Fixation: Diverse genera such as Bacillus, Pseudomonas, Rhizobium, Fusarium, and Klebsiella have been documented in both leguminous and non-leguminous hosts, where they support nitrogen assimilation (14). This capacity is underpinned by the enzyme nitrogenase, which facilitates the conversion of atmospheric nitrogen into plant-available forms. The activity of nitrogenase has been experimentally demonstrated in several endophytic strains through acetylene reduction assays (15). Many endophytic bacteria release organic acids and enzymes that transform insoluble phosphorus into bioavailable forms (16). For example, in wheat ecosystems, both endophytic and bacterial populations of rhizosphere have been shown to enhance phosphorus solubilization efficiency under nutrient-deficient conditions (17). Phytohormone Modulation Beyond mineral nutrition, endophytes significantly influence plant development by modulating phytohormone dynamics. They are known to synthesize phytohormones such as indole-3-acetic acid (IAA), gibberellins, cytokinins, and ethylene modulators, including 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. Together, these molecules stimulate root and shoot development, alleviate abiotic stress, and even facilitate beneficial associations such as mycorrhization (18). The production of growth regulators allows endophytes to orchestrate complex physiological changes in their hosts (19) (20). Siderophore Production & Iron Acquisition Endophytes often produce siderophores, which are small, high-affinity iron-chelating compounds. In soil and plant tissues, iron is mostly present in an insoluble form (Fe³⁺) that plants cannot absorb. Bacterial and fungal siderophores solubilize this iron, forming a complex that can be recognized and taken up by the plant. This directly improves the plant’s iron nutrition, which is vital for chlorophyll synthesis and electron transport in photosynthesis. Additionally, by sequestering all available iron, endophytes can starve and inhibit the growth of pathogenic microbes in the plant’s immediate environment, a form of biological control (21) Osmolyte Production and Abiotic Stress Mitigation Beyond the mentioned ACC deaminase, endophytes directly help plants cope with drought, salinity, and heavy metal stress. Endophytes can produce osmolytes like proline, glycine betaine, and trehalose. These compounds help maintain cell turgor pressure and protect cellular structures (like enzymes and membranes) under water-deficit or high-salinity conditions. They can also enhance antioxidant production (e.g., catalase, superoxide dismutase) to detoxify reactive oxygen species (ROS) that accumulate under stress. Leads to significantly improved plant growth and survival under challenging environmental conditions, which is critical in the face of climate change (22). Modulation of Carbon Metabolism and Photosynthesis Endophytes can influence the plant’s primary carbon metabolism, enhancing its energy production capacity.They can increase the activity of key photosynthetic enzymes (like RUBISCO) and chlorophyll content, leading to a higher photosynthetic rate. Some endophytes also influence sugar metabolism and partitioning, ensuring better carbon allocation to growing parts of the plant.Results in increased biomass accumulation, higher yields, and more energy for the plant to invest in other defense and growth processes (23). The ISR and SAR distinction Bacterial and fungal endophytes significantly boost a plant’s defensive capacity by priming an innate immune response known as Induced Systemic Resistance (ISR). This primed state is orchestrated mainly through jasmonic acid and ethylene hormones, preparing the plant to mount a swift and robust defense against herbivorous insects and necrotrophic fungi (24). This mechanism differs from Systemic Acquired Resistance (SAR), which is typically initiated by pathogen attack and is dependent on salicylic acid signaling and the widespread activation of pathogenesis-related (PR) genes to combat biotrophic pathogens (25). A key distinction lies in the strategy of these endophytes: bacterial strains often elicit a classic ISR response, whereas certain fungal endophytes can uniquely stimulate elements of the SAR pathway or fine-tune the interplay between SA and JA signaling. This sophisticated regulation, a form of defense priming, equips the plant with versatile protection against a wider array of threats (26). Consequently, by activating ISR and sometimes co-opting SAR components, endophytic … Read more

First finding of Heritiera littoralis and its significance for Mauritian mangrove conservation

Naohiro Matsui¹
Nabiihah Bibi Roomaldawo²
Satoshi Sasakura³

Introduction Importance of mangroves in Small Island Developing States (SIDS) In Small Island Developing States (SIDS) like Mauritius, mangroves are particularly important for strengthening their resilience to climate change, providing important habitats for marine life as fishery resources, and food security and livelihoods for coastal communities [1]. Mangroves act as a natural barrier against natural disasters, especially storms and floods and have the capacity to prevent more than US$65 billion in damage annually by reducing coastal flood risk in areas inhabited by an estimated 15 million people [2]. In SIDS, mangroves function as natural barriers against storms, erosion, and flooding, and have the capacity to prevent more than US$65 billion in damage annually by reducing coastal flood risk in areas inhabited by an estimated 15 million people [3]. Mangroves capture sediments and pollutants that can run off into the ocean, while seagrass beds provide an additional barrier to prevent mud and silt from covering coral reefs. Coral reefs, on the other hand, protect seagrass beds and mangroves from strong waves. Therefore, the collapse of any of its components can lead to the collapse of the entire system, meaning that an integrated coastal ecosystem management (ICEM) approach is essential to ensure the overall health and resilience of island coastal areas [4]. Status of mangrove ecosystems in Mauritius and conservation issues Mauritius was previously thought to be home to only two species of mangrove plants [5-7], with Rhizophora mucronata (RM) being the most dominant, and Bruguiera gymnorhiza (BG). Bunting et al. (2022), using a global satellite dataset called Global Mangrove Watch (GMW), reported the mangrove area in Mauritius to be about 4.32 km² [9]. Mangroves are distributed along the northeast, east, and southeast coasts, with smaller patches in southwestern regions. The mangrove forests in the southeastern region, where this study was conducted, are the most developed and mature, as evidenced by their tall tree heights and large tree sizes. The factors that determine mangrove expansion and productivity vary depending on the type of mangrove forest (delta, marine, estuarine, lagoonal), so it is important to understand the environmental factors specific to each type [10, 11]. In each type, mangrove area is not determined by a single factor, but by a complex interplay of multiple factors such as hydrology (tides, waves, current velocity), freshwater and nutrient supply, sediment supply and stability, salinity, and human activities. Mangroves in Mauritius are predominantly estuary and lagoon type [6]. Salinity gradients and human activities are thought to have distinctive effects on mangrove forests in estuarine types, while wave activity and water quality in the lagoons are distinctive factors affecting mangrove forests in lagoonal types. JICA Project for the Development of an Integrated Coastal Ecosystem Management System in the Republic of Mauritius Since 1995, the Government of Japan, through the Japan International Cooperation Agency (JICA), has made long-term contributions to the conservation and restoration of Mauritius’ coastal ecosystems, as well as the preservation of coastal fisheries resources and the environment. In 2022, JICA, in cooperation with the Government of Mauritius, launched the technical cooperation project titled “The Project for the Development of Integrated Coastal Ecosystem Management System.” The overall goal of this project is to promote the conservation and restoration of coastal ecosystems through integrated coastal ecosystem management systems, aiming for healthier and more resilient states. This research was conducted as a component of this initiative. Aims of this study Although the ecological and socio-economic importance of mangroves is recognized, scientific research on mangroves in Mauritius is still limited. In Mauritius, only two mangrove species have been identified, RM and BG [6]. While this recognition has been going on for a long time, this study confirmed for the first time that Heritiera littoralis (HL) is present in Rivière des Creoles (hereinafter called RC). The goal of this study is to scientifically document its presence, understand the growing conditions in which HL thrives, and provide a basis for ensuring its long-term health and sustainability of the mangrove ecosystem in RC and other coastal areas of Mauritius. Materials and methods Site description and mangrove survey The same estuary-type mangrove as that found at RC (where HL was found) is also present 2 km north at Rivière Nyon (RN) (Fig. 1). They belong to different estuarine systems regarding freshwater inputs from different rivers, different catchment characteristics, and different estuary shapes and openings to the sea. 3 plots (C1, C2, C3) and 3 plots (N1, N2, N3) with the size of 20 x 25m were set up at RC and RN, respectively. All stems were tagged with numbering tape. 555 trees at 6 plots in RC and RN were measured for height and diameter at breast height (DBH), and from which basal area and stand density were calculated. The position of measured trees also was also determined. RM sometimes has plural stems in one single tree. In that case, the ground level measurement was done at 30 cm above the prop roots. Tree heights were subsequently measured with a measuring pole and/or by visual observation. Ground level survey Topography, or ground elevation, determines the dynamics of water flow and nutrient inputs within mangrove forests. It is considered the most important factor for mangrove growth [12, 13] and is recognized as crucial for the distribution of mangrove species [14]. Topography is closely related to soil properties, and in turn soil properties are closely related to plant growth. Therefore, mangrove growth can be better explained when soil properties are taken into consideration with topography [15]. Ground level measurements were taken at 5-meter intervals from the coast inland through the mangrove forests in both the RC and RN plots. These measurements were performed using an Ushikata pocket compass (Model S-25, Ushikata Surveying Instruments Co., Ltd., Japan). Soil analysis For the assessment of soil moisture and bulk density, undisturbed soil samples were obtained using 100 cm³ stainless steel sampling tubes (Daiki Rika Kogyo Co., Ltd., Japan) at different depths with 5 cm intervals till 30 or 35cm. The pH and electrical conductivity (EC) of the fresh soil samples were measured after … Read more

Occurrence, detection and transmission of Pseudomonas syringae pv. lachrymans from the seeds of Cucumber (Cucumis sativus L.) in Rajasthan

Poonam Arora¹
Dilip Kumar Sharma²

I. Introduction The cucumber (Cucumis sativus L.), a member of the Cucurbitaceae family, is a primitive vegetable that originated in India and is consumed as a cooked or salad produce. 1. It is a wide-ranging and heterogeneous family that comprises worldwide 118 genera and 825 species2, 3 and 36 genera and 100 species in India4. It is widely known as Kheera and Gherkins in the tropics, subtropics and temperate zones of India5. In India cucumber are grown as a vegetable that is used for domestic purpose and exported to other countries for foreign income. Bharatpur, Jaipur, Bikaner, Dausa, Hanumangarh, Pali, Sawai Madhopur, Sikar, Sirohi, Karauli and Dholpur are major cucumber-producing districts in Rajasthan. The disease angular spot (ALS) in cucumber was first discovered in the United States in 1913 and the pathogenic organism was identified in 1915 by Smith and Bryan. In Japan, it was first reported in 1957. In Turkey, it may cause considerable yield losses in both greenhouses and field agriculture 6,7. The crop is invaded by several fungi, bacteria, viral diseases which reduced the quantitative and quality values of the crop. ALS is caused by Pseudomonas syringae pv. lachrymans (Smith & Bryan) Young, Dye & Wilkie. The complex species Pseudomonas syringae divided into 64 pathovars on the basis of pathogenic characters, and Pseudomonas syringae pv. lachrymans (PSL) is one of them8-14. Following the pathogen’s attack, the cucumber leaves developed vein-limited, water-soaked lesions with or without a chlorotic halo. Water-soaked spots on fruits that could be deformed 15-16. Angular leaf spot (ALS) is limiting its open-field production17-18. It could result in large yield reductions in both field and greenhouse crops7. Cucumber and other cucurbit producers in Turkey suffered significant harm and financial loss as a result of the disease’s proliferation-promoting climate19, 20. It caused water-soaked blisters on the leaves, which eventually turned necrotic and decreased the leaf’s ability to photosynthesize21, 22. Depending on the species’ susceptibility, ALS can cause yield losses of up to 30%–60% in fruits by reducing the ability to photosynthesis of diseased leaves 16. Once attacked by PSL on the cucumbers the yields decrease significantly, caused by reduced photosynthetic capacity of the infected foliage, and the disease is difficult to control22. In China, during 2014-2016, the disease incidence varied from 15 to 50% in different fields, causing 30–50% of yield losses14. The disease is responsible for economic losses in cucumber production worldwide9, 21. With 2.1 million hectares and 71.3 million tons produced in China, the USA, and the EU, uninfected cucumber farming is extremely important 23. The bacterium is Gram negative and KOH solubility test negative but levan and catalase are positive. It is oxidase, potato rot; nitrate reduction and arginine dihydrolase negative. The bacterium is non-fluorescent, non-hydrolyzing of starch and gelatin24. The goal of this research was to examine the transmission and detection of the disease, and this study was carried out because PSL needs appropriate detection techniques to enhance effective management strategies. Pathogen isolation and biochemical identification are the primary detection methods, although molecular approaches like rep-PCR and PMA-qPCR have been reported to be employed for PSL detection 25-27. In addition to offering quick and sensitive detection, loop-mediated isothermal amplification assays (LAMP) 28-31have been widely used for plant pathogen detection because they can be used outside of traditional laboratory settings and offer a variety of detection strategies 32. II. Materials and Methods (I) Incidence of pathogen All 102 seeds, 50 fruits samples and various infected plant parts of cucumber collected from storage houses, market and farmers field of 16 districts of Rajasthan, were brought to the laboratory to know the disease sign on various parts of plant. In order to isolate the pathogen, the seed samples and other plant components were surface sterilized and incubated under aseptic conditions on moistened blotter papers in the context of Petri plates and Nutrient Agar media. To isolate the pathogen, all of the cucumber seed samples underwent dry seed examination (DSE) and were incubated on a moistened blotter in SBM 33. The pure form of bacterial colonies were incubated at 30o C for 48 hrs, and were used for various biochemical tests viz. Gram’s staining, KOH solubility test, and LOPAT24, 34-35, and pathogenicity test24 to identify of the species of bacteria. The host plant and other plant species were used to investigate the pathogenicity of the pure bacterial isolates that were found using different techniques. The diseased fruit and other plant parts are subjected to incubate on NA media and moistened blotter papers to know the characterization of the bacterial colony i.e. shape, size, elevation, color, pigmentation, margin, and growth pattern. (ii) Disease transmission For transmission tests, two naturally infected cucumber seed samples (Lab. ac. no. CU-1412 and CU-1420) with 78 and 82% infection on the standard blotter method (SBM) and 94–100% on Kings medium B were chosen. The 100 seeds per category per sample were sowed on moist blotters (10 seeds/plate) and 1% water agar medium in test tubes (1 seed per test tube, TTSST). The seeds were then incubated at 25±2o C for 12/12 h cycles of light and darkness up to 7 and 14 days, respectively. In the pot experiment, 100 seeds per category per sample were planted in pots (two seeds per pot), and information on symptoms, seed germination percentage, and death was noted. At various phases of plant growth, the pathogen was separated from the affected portion of the plant. (iii) Pathogenicity test The bacterial isolates were artificially inoculated utilizing methods like smothering of seeds, stab inoculation of seedlings at the 3-4 leaf stage of the crop, and other plant parts. The host and other plants, such as round, bitter, bottles, and sponge gourds, were used to test the pathogenicity. Cucumber seeds that were susceptible to PSL were planted in plastic pots with sterilized soil and kept in a standard development chamber at 250°C during the day and 220°C at night. Sodium lamps were used to illuminate the pots for 16 hours17. The bacterial inoculums yielded for 24 hrs on Kings medium B (agar medium) at 280C … Read more

Influence of Light Intensity and Growing Media on the Growth and Yield of Solanecio biafrae

Kehinde-Fadare A. F.
Olajide Olubunmi
Arowosegbe Temitope

Introduction Solanecio biafrae (family Asteraceae) [1] is an underutilized indigenous leafy vegetable widely consumed in parts of West and Central Africa. In southwestern Nigeria, it is locally known as worowo, while in Sierra Leone, it is referred to as bologi. The plant is predominantly found under the shade of tree crops and is commonly cultivated beneath cocoa and oil palm plantations, where the humid, well-drained, and fertile soils favour its growth [ 2] Despite its nutritional and economic potential, cultivation of S. biafrae remains limited to small-scale production in Nigeria, Uganda, and Cameroon [2]. Its production is further constrained by environmental and agronomic challenges, leading to irregular production and threatening its availability [ 3]. The domestication and large-scale cultivation of S. biafrae is therefore crucial to ensure consistent production and to promote its utilization as a sustainable food resource. Among the factors that determine its growth performance are light intensity and growing medium. Light serves as the primary energy source for photosynthesis and is a major driver of plant growth and development. [4]. Suboptimal light conditions can limit crop performance, whereas adequate light promotes photosynthetic activity and vegetative growth. Previous research has shown that low to moderate light intensity can enhance leaf production in S. biafrae [5]. In addition to light, the choice of growing medium influences nutrient availability, root development, and overall yield, making it a key determinant of successful vegetable production. Despite these perceptions, limited research has investigated the combined effects of light intensity and growing media on the performance of S. biafrae. This study was therefore conducted to examine the influence of varying light intensities and growing media on the growth and yield of S. biafrae, with the aim of identifying optimal production conditions for sustainable cultivation. Objectives The primary objective of this study was to evaluate the effects of different light intensities and growing media on the growth and yield of Solanecio biafrae. Specifically, the study was aimed at: 1. Assessing the individual effects of light intensity and growing media on leaf number, plant height, and fresh weight. 2. Examining the interaction between light intensity and growing media on growth and yield performance Materials and Methods Experimental Site The study was conducted at the teaching and research farm of the Faculty of Agricultural Sciences, Ekiti State University (EKSU), Ado Ekiti, located in the southwestern region of Nigeria characterized by a humid tropical climate rainforest zone. The area experiences a bimodal rainfall pattern, with an annual average rainfall of 1,200–1,500 mm and temperatures ranging between 25°C and 30°C. The experimental period lasted for two months. Planting Material Healthy stem cuttings of Solanecio biafrae were collected from established local farms in the vicinity and were sterilized in a solution of food-grade hydrogen peroxide before planting. Experimental Design The experiment was laid out in a factorial arrangement (3 × 4) in a completely randomized design (CRD), with three replications. The factors were: Light intensity: half shade (HS; 600 flux), more intense shade (MIS; 63.6 flux), and full light (FL; 1120 flux). Growing media: rice husk + cocopeat (M1), rice husk alone (M2), biochar (M3), and topsoil (M4). Treatments and Management Shade intensities were achieved using different tree stands of diverse shades and an open field, while flux values were measured using a light meter. Growing media were prepared in equal proportions by volume. Plants were transplanted into growing bags each containing 5 kg of medium Data Collection Growth and yield parameters were recorded at 8 weeks after planting (2 months). Measurements included: Number of leaves: Plant height (cm): measured from the soil level to the apical bud. Fresh weight (g): determined by harvesting and weighing shoots immediately after collection. Statistical Analysis Data collected were subjected to analysis of variance (ANOVA) using IRRI STARS software version 2.0.1. RESULTS Effect of Light Intensity on Growth and Yield of Solanecio biafrae Light intensity significantly influenced plant growth and yield (Table 1). Plants under half shade (HS; 600 flux) produced the highest number of leaves (23.38), followed by more intense shade (MIS; 63.6 flux; 21.62), while full light (FL; 1120 flux) recorded the lowest (20.88). Plant height was greatest under MIS (35.31 cm), intermediate under HS (24.44 cm), and lowest under FL (20.69 cm). Fresh weight was similar under FL (20.77 g) and HS (20.10 g), but significantly lower under MIS (13.99 g). Effect of Growing Media on Growth and Yield Growing media also had a marked effect on plant performance (Table 1). Biochar (M3) and rice husk + cocopeat (M1) supported the highest leaf numbers (26.33 and 25.25, respectively), plant heights (32.00 and 31.33 cm), and fresh weights (21.27 g and 22.39 g). In contrast, rice husk alone (M2) and topsoil (M4) resulted in significantly fewer leaves (17.92 and 18.33), shorter plants (22.42 and 21.00 cm), and lower biomass (15.49 g and 14.00 g). Interaction of Light Intensity and Growing Media Significant interactions were observed between light intensity and media (Table 2). Under HS, biochar (HS × M3) produced the highest leaf number (31.00) and plant height (62.75 cm), while HS × M1 gave the greatest biomass (24.90 g). Under MIS, rice husk + cocopeat (MIS × M1) supported the highest leaf. Discussion The findings highlight the role of light intensity in determining the performance of S. biafrae. Moderate shading (HS) enhanced leaf production compared to FL and MIS, backing up earlier work by [ 5]. The improved performance under HS likely reflects reduced photo-inhibition and increased leaf expansion efficiency. Plant height was greatest under MIS, a typical shade-avoidance response where limited light availability induces stem elongation to maximize light capture [ 6]; however, this elongation did not translate into greater biomass, as excessive shading compromised assimilate production. Growing media also strongly influenced growth and yield. Biochar and rice husk + cocopeat consistently supported more vegetative growth, likely due to improved nutrient retention, aeration, and water-holding capacity. Similar benefits of organic substrates for vegetable production have been widely reported [7]. In contrast, rice husk alone and topsoil yielded poor growth, likely … Read more

Fungal Alchemy in Action: Scalable, Cell-Free Mycoherbicides for Sustainable Agriculture

Ajay Kumar Singh
Akhilesh Kumar Pandey

1. Introduction Weeds pose a significant threat to global agriculture by competing with crops for essential resources such as nutrients, water, and light, often thriving under adverse conditions. Their unchecked proliferation leads to reduced yields, elevated production costs, and diminished market profitability. In India and the United States alone, annual weed-related losses in major crops like soybeans and dry beans are estimated at USD 11 billion and USD 17.2 billion, respectively1, 2, 3. Chemical herbicides have long served as the primary tool for weed management, targeting critical metabolic pathways in plants. Glyphosate, the most widely used herbicide globally, inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimic acid pathway, thereby disrupting aromatic amino acid biosynthesis4, 5. By 2019, herbicides accounted for 47.5% of the 2 million tons of pesticides used worldwide, with China, the USA, Brazil, and India among the top consumers6,7. However, excessive and indiscriminate use has led to the emergence of herbicide-resistant weed populations—particularly against glyphosate and chlorsulfuron—alongside environmental persistence and potential health risks due to their recalcitrant nature8,9,10. To counter resistance, novel synthetic herbicides have been developed, including cinmethylin (targeting acyl-ACP thioesterase), cyclopyrimorate (inhibiting homogentisate solanesyltransferase), and tetflupyrolimet (acting on dihydroorotate dehydrogenase)11,12,13. However, high genetic homology between crops and weeds complicates target specificity, raising concerns about crop safety and unintended phytotoxicity14,15 As a sustainable alternative, bioherbicides—biological agents derived from plants, bacteria, fungi, or viruses—have gained increasing attention16,17. Fungi, in particular, are favored for industrial-scale production due to their host specificity, potent bioactivity, and environmentally benign profiles18,19 . Additionally, bioherbicides offer lower discovery and development costs compared to synthetic herbicides, with relatively fewer regulatory hurdles. Nonetheless, commercial adoption remains constrained by challenges in efficacy, formulation stability, and regulatory compliance20,21,22 Recent research underscores the potential of cell-free phytotoxic fungal metabolites to enhance weed suppression while reducing environmental persistence and off-target effects 23,24,25,26,27. Moreover, the use of industrial residues as fermentation substrates supports cost-effective production and aligns with circular economy principles. This review critically evaluates the current landscape of fungal herbicides, with a particular focus on cell-free phytotoxic metabolites as scalable, sustainable solutions for weed management. It also examines commercially available fungal products and identifies key scientific and industrial barriers to market success. The novelty lies in bridging cutting-edge scientific innovation with industrial feasibility to chart a path toward commercially viable bioherbicidal technologies. 2. Production Strategies for Fungal-Based Herbicides Derived from Metabolite Extracts The development of fungal herbicides typically involves two core stages: the first stage is screening and isolation of microorganisms with phytotoxic activity, and the second stage is large-scale cultivation for formulation and application. However, when targeting cell-free metabolites, additional steps are required—particularly the extraction and purification of bioactive compounds—depending on their chemical nature, which may simplify or complicate downstream processing. The first phase, Isolation and Screening, begins with identifying dominant weed species in the target environment and evaluating the chemical herbicides currently used for their control to understand potential resistance mechanisms. Fungal candidates are then isolated either from infected weed tissues or from rhizospheric soils where weed-crop interactions are evident28,29,30. Alternatively, reference strains from established fungal culture banks may be utilized. These isolates are screened using Petri dish assays with weed seeds, assessing phytotoxic responses such as inhibition of germination, reduction in shoot and root growth, and other indicators of herbicidal activity. The second phase of bioherbicide development involves selecting the most promising microbial strains and subjecting them to metabolite characterization. This step is critical for elucidating the bioherbicide’s mode of action (MOA). Advanced analytical tools such as mass spectrometry and computational techniques like molecular docking are commonly employed for profiling and identifying active phytotoxic compounds. In the third phase, the focus shifts to evaluating the mycoherbicide’s efficacy and target spectrum across various weed species. This assessment can be conducted using both isolated metabolites and whole fungal cultures. Greenhouse trials are recommended to simulate natural conditions and generate ecologically relevant data. Toxicity and ecotoxicity assays are also essential, particularly on crop species related to the target weeds, to determine selectivity and minimize off-target effects. Once efficacy and selectivity are confirmed, the production process is optimized to enhance metabolite yield. This involves adjusting fermentation parameters based on recent literature and experimental data. The resulting product is then formulated and subjected to further testing to validate its performance across a broader weed spectrum and its safety profile for crops31,32 The fourth and final phase involves scaling up production through fermentation, followed by purification of the active metabolites for field trials. Successful field validation paves the way for product registration, patenting, and commercialization. 2.1 Production Dynamics and Strategic Optimization Fermentation is a pivotal stage in mycoherbicide production, directly influencing yield and cost-efficiency. Currently, one of the major limitations of biological herbicides is their higher production cost compared to chemical alternatives. A techno-economic analysis by Mupondwa estimated that a facility with two 33,000 L fermenters producing 3,602 tons annually would require a capital investment of USD 17.55 million and incur annual operating costs of USD 14.76 million. Despite this, the payback period is under one year, with a net present value (NPV) of 7%, indicating commercial viability. To further enhance cost-effectiveness in microbial bioherbicide production, several strategies can be implemented, including the use of agro-industrial residues as alternative carbon and nitrogen sources to reduce raw material costs and promote circular economy principles33,34,35; optimization of fermentation processes through statistical tools such as response surface methodology; deployment of microbial consortia to broaden the spectrum of target weed species; and careful selection of fermenter types and operational modes aligned with the metabolic profile and growth kinetics of the producing organism10,36,37. Collectively, these approaches improve production efficiency and economic viability, thereby supporting the wider adoption of microbial bioherbicides in sustainable agriculture. 2.1.1. Preliminary Process Development The upstream development of microbial bioherbicides based on cell-free metabolites begins with the selection of pre-characterized microbial strains from established culture banks. These strains must demonstrate high efficacy in controlling one or more target weed species, as validated through greenhouse or field trials. Optimizing fermentation conditions—including nutritional, chemical, physical, and biological … Read more

Microbiome of centenary trees growing around historical monuments

S. F. Abdulloeva¹
S. S. Fayzullayev¹
B. I. Turaeva²

Introduction Trees are one of the main components of the Earth’s biosphere and play an essential role in maintaining ecosystem structure, stability, and biodiversity [1]. They provide important ecosystem services such as nutrient retention and water filtration [2]. In parks, recreational areas, and historical sites, trees are valued for their health benefits and aesthetic importance. Ancient trees, being physiologically active throughout the year, play a significant role in enriching the atmosphere with oxygen through photosynthesis [3]. The tree microbiome consists of microorganisms (bacteria and micromycetes) inhabiting the roots, stems, and leaves, along with their genetic material. Some microorganisms enhance the physiological processes of trees and increase their resilience to environmental stresses such as drought and extreme temperature [4]. The composition of the microbiome is influenced by factors such as tree age, soil properties, climate, and humidity [5]. In recent decades, infections of ancient and ornamental trees by various phytopathogenic microorganisms have been increasing due to adverse climatic and abiotic factors [6]. This not only poses a threat to trees but also contributes to the rise of allergic diseases in humans, thus representing a serious environmental risk [7]. Pathogenic microorganisms alter plant physiology and metabolism, leading to diseases. They may exist on plant surfaces as epiphytes or within tissues as endophytes, occupying intercellular spaces [8]. Endophytic and epiphytic microorganisms can be either beneficial and symbiotic or phytopathogenic, causing plant diseases [9]. Endophytic microorganisms include diverse ecological groups such as root and soil endophytes [10]. Some endophytes may shift between mutualistic and latent pathogenic stages during their life cycle [11, 12]. Therefore, endophytes exhibit multiple functional characteristics at different life stages. The use of antagonistic endophytic microorganisms is one of the most effective biological control strategies against plant pathogens [13, 14]. Endophytes are also promising sources for developing biological preparations and bioactive compounds such as alkaloids, cytochalasins, polyketides, terpenoids, flavonoids, and steroids [15–17]. These substances have great potential for application in medicine, agriculture, and industry. Considering the vast plant diversity worldwide, endophytic micromycetes are a valuable source for discovering new natural biological control agents [18]. Microorganisms are dispersed through soil, water, air, and various anthropogenic factors. When soil conditions change, saprophytic microorganisms can multiply rapidly [19]. The phytopathogenic micromycete Rhizoctonia solani, which causes various plant diseases, was isolated and its morphological characteristics studied. In laboratory conditions, the pathogenic properties of most isolated phytopathogenic microorganisms were confirmed [20]. Soil microbial populations often include bacterial genera such as Pseudomonas, Bacillus, and Pasteuria, which have strong potential for biological control of nematode populations [21]. Promising results were also obtained from experiments using biological control agents against Pantoea agglomerans, the causal agent of fire blight. Following these studies, the mechanisms of antagonist activity were examined in detail [22]. To develop effective biological control methods and create environmentally friendly biological agents, it is necessary to isolate antifungal and antibacterial antagonist strains from ancient trees [23]. However, current research on endophytic microorganisms remains limited, leading to the spread of diseases caused by them. Therefore, studying the diversity of endophytic and epiphytic microorganisms and their potential effects on tree species and human health is of great scientific importance. Research Area and Methods The research was conducted in the area surrounding the Ulugbek Observatory and Sherdor Madrasah in Samarkand, Uzbekistan. The Ulugbek Observatory, built in 1428–1429 on Choponota Hill near the Obirakhmat stream, is one of the rare examples of 15th-century architecture. Around the observatory, ancient plane trees (Platanus orientalis) are found. The Sherdor Madrasah, located on Registan Square, dates to the 17th century and was included in the UNESCO World Heritage List in 2001. Around this monument grows an ancient Juniperus virginiana (Virginia juniper), also known as pencil cedar, which was planted in 1873 and is notable for its evergreen foliage. Plant samples were collected aseptically from the bark, branches, leaves, flowers, and immature fruits of several ancient trees near these monuments — including Pinus nigra, Picea pungens Engelm., Pinus eldarica Medw., Aesculus sp., and Morus sp. (near the Ulugbek Observatory), and Thuja orientalis, Juniperus virginiana, Pinus sylvestris, Juniperus sp.1, and Morus sp. (around the Sherdor Madrasah). Samples were taken from a total of six trees near the Ulugbek Observatory and eight trees near the Sherdor Madrasah. A seasonal study revealed that microbial activity was highest in spring, while lower levels were observed in summer and autumn. In the laboratory, all procedures were performed in a biological safety cabinet (BSC-1300IIA2-X). To isolate epiphytic microorganisms, plant material was first treated with 3% hydrogen peroxide for 15 minutes and then rinsed ten times with sterile distilled water. Small tissue sections were excised using sterilized scalpels and tweezers and inoculated onto potato dextrose agar (PDA) plates. To isolate endophytic microorganisms, plant samples were covered with sterile quartz sand in porcelain dishes and inoculated into PDA medium. The inoculated samples were incubated at temperatures ranging from 20°C to 36°C (Figure 1) Figure 1. Samples taken from the Ulugbek Observatory and Sherdor Madrasah and colonies of microorganisms that developed in the samples. From the 2nd day of the study, the formation, that is, the development of bacterial and micromycete colonies was observed in the samples planted. Data analysis: The results obtained were identified using generally accepted methods in microbiology, genetic and MALDI-TOF MS methods. Pure isolates were isolated by re-sowing microorganisms on nutrient media (Figure 2). When studying the developed microflora from samples taken from trees, the samples obtained were incubated on the above nutrient media for 6-7 days. To isolate pure cultures from the samples, the generally accepted method of re-sowing on PDA nutrient media was used. In the next stage of the study, studies were conducted on the isolation of pure cultures from the colonies of microorganisms that developed in the samples. Figure 2. Results of the study conducted in laboratory conditions. A-Bacterial isolates isolated from samples taken from Sherdor madrasah; B-micromecit isolates; C-Bacterial isolates isolated from samples taken from Ulugbek Observatory; D-micromecit isolates; In order to identify the types of pure isolates, the morphological characteristics of the microorganisms were examined. … Read more

Spatial Assessment of Carbon Sequestration Dynamics in Southern Guinea Savannah Agro-Ecological Zone of Taraba State, Nigeria

Shamaki Rimamnyang Ayina¹
Oruonye, E.D¹
Benjamin Ezekiel Bwadi¹
Hassan Musa²

Introduction Climate change, driven primarily by increasing atmospheric concentrations of greenhouse gases such as carbon dioxide, remains one of the most pressing environmental challenges of the twenty-first century [1]. Terrestrial ecosystems play a crucial role in mitigating climate change by sequestering carbon in both biomass and soil organic matter. Savannah ecosystems, in particular, are dynamic landscapes that act as either carbon sinks or sources depending upon land use, climatic variability, and management practices. Nigeria’s Guinea Savannah, which forms a broad transitional belt between the humid forest in the south and the drier Sudan and Sahel savannahs in the north, is a significant ecological zone where pressures of agriculture, grazing, and settlement intersect with climate dynamics to influence carbon sequestration potential [2]. The Southern Guinea Savannah (SGS) agro-ecological zone is characterized by relatively high rainfall lasting six to eight months, tall grasses interspersed with trees, and soils that, although fertile, are vulnerable to degradation if unsustainably managed [3]. Taraba State lies across multiple ecological zones, including the Southern and Northern Guinea Savannahs and the Montane Forest, giving it diverse topography, rainfall distribution, and vegetation patterns that influence carbon sequestration dynamics. Recent climate analyses in Taraba State reveal significant changes in precipitation and temperature that directly affect the carbon balance of the landscape. Asa and Zemba [4] found that annual rainfall ranged from 733 mm to 2238 mm across different stations in southern Taraba, with rainy days spanning between 164 and 262 days. Importantly, the onset of rainfall has shifted later in the past decade, while mean temperatures exhibit a consistent upward trend across all stations, suggesting increasing evapotranspiration and moisture stress [4]. Complementary findings by the Global Journal of Science Frontier Research indicate rising temperatures across most stations in Taraba, except for Gembu in the highlands, and evidence of delayed rainfall onset in many areas, with a general shortening of the rainy season length. These climatic changes reduce vegetation productivity, alter biomass growth, and accelerate soil organic carbon decomposition, thereby weakening the ecosystem’s ability to function as a net carbon sink. In parallel, remote sensing and land use/land cover studies have highlighted rapid forest degradation and vegetation loss in Taraba State. Ojeh et al [5] documented significant declines in forest cover in the Kurmi Local Government Area between 1999 and 2019, with corresponding increases in bare land and built-up areas. Abba et al [6] reported that thick forest cover in the central part of Taraba declined dramatically from over 80% in 2006 to much lower levels by 2018, largely replaced by fragmented vegetation and bare surfaces. Similarly, Musa, Saddiq, and Abubakar [7] found marked vegetation loss in Gashaka Gumti National Park, even within protected zones, due to encroachment and anthropogenic pressures. Such land cover transitions reduce aboveground biomass carbon stocks, diminish litter input into soils, and exacerbate soil organic carbon depletion. At the same time, empirical studies in Taraba and other parts of Nigeria have revealed both the potential and vulnerability of carbon sequestration in savannah ecosystems. Yani, Yekini, and Dishan [8] assessed aboveground, belowground, and soil carbon stocks across three ecological zones in Taraba and found that Montane Forest reserves had significantly higher sequestration potential than Guinea Savannah zones, underscoring the ecological gradient in carbon storage. Lawal [9] showed that conservation tillage and cover crops in the Northern Guinea Savannah improved soil organic carbon pools, pointing to management as a key determinant of sequestration capacity. Danjuma [3] further demonstrated that land use type and soil depth significantly influence carbon stocks in Katsina’s Guinea Savannah, with croplands and degraded lands storing far less carbon than forest or fallow land. Despite these insights, major knowledge gaps remain. Most existing studies provide static carbon stock estimates without examining the temporal dynamics of sequestration across decades of land use change and climatic variation. In addition, spatial heterogeneity in carbon sequestration across soils, vegetation types, and land use mosaics of Taraba’s Southern Guinea Savannah remains poorly mapped. Furthermore, while several localized soil fertility and land degradation studies have been undertaken in Taraba [10], few have systematically integrated climate trend data with land cover change and carbon sequestration potential. This creates a serious research gap, as the Southern Guinea Savannah in Taraba is undergoing rapid transformation through deforestation, agricultural expansion, and unsustainable exploitation, yet its carbon sequestration potential and changing role in climate regulation remain underexplored. Therefore, this study undertakes a spatially explicit assessment of carbon sequestration dynamics in the Southern Guinea Savannah agro-ecological zone of Taraba State. By integrating spatial analysis of land cover change with carbon stock estimation and climatic trends, the research provides crucial evidence of how one of Nigeria’s most important ecological zones is shifting from a carbon sink towards a potential carbon source. This linkage highlights the urgency of sustainable land management, forest conservation, and policy interventions that can mitigate further carbon losses while enhancing the adaptive capacity of local ecosystems and communities. In doing so, the study directly addresses a pressing research problem: the lack of spatially and temporally grounded data on carbon sequestration dynamics in Taraba’s Southern Guinea Savannah, which is vital for both national climate commitments and global mitigation strategies. Description of the Study Area The study was conducted in the Southern Guinea Savannah agro-ecological zone of Taraba State, Nigeria. This zone occupies the southern part of the state and encompasses the Local Government Areas (LGAs) of Wukari, Donga, Takum, Kurmi, Bali, Gashaka, and Sardauna. Geographically, it lies between latitudes 6°30′N and 8°30′N and longitudes 10°00′E and 11°30′E, covering an estimated area of approximately 25,120 km² [11, 12]. The region experiences a tropical wet-and-dry climate with two distinct seasons: a wet season (April–October) and a dry season (November–March). Annual rainfall ranges between 1,200 mm and 1,800 mm, with mean annual temperatures varying from 25°C to 32°C. These climatic conditions support the Guinea Savannah vegetation, characterized by grasslands interspersed with shrubs, scattered trees, and gallery forests along rivers [4, 13]. The topography varies from low-lying plains in the west to rugged highlands in the east, particularly in Sardauna … Read more