Phytohormone Production Research Articles

Unveiling the rhizosphere microbiome of Dendrobium: mechanisms, microbial interactions, and implications for sustainable agriculture

The rhizosphere microbiome plays a critical role in plant health and productivity by fostering beneficial microbial interactions that support nutrient cycling, stress tolerance, and disease suppression. In the context of Dendrobium, understanding its interactions is essential for optimizing cultivation and promoting sustainable agricultural practices. This review explores the rhizosphere microbiome of Dendrobium, focusing on the mechanisms and microbial interactions that contribute to plant health, stress tolerance, and growth and their implications for sustainable agriculture. This study highlights the diverse composition of microbial communities in the Dendrobium rhizosphere, including key bacteria (e.g., Pseudomonas fluorescens and Bacillus subtilis), fungi (e.g., Glomus spp.), and biocontrol agents (Trichoderma spp.), and discusses their roles in nutrient cycling, disease suppression, and plant growth promotion. This review emphasizes the significance of plant-microbe signaling, such as the production of flavonoids, phytohormones, and strigolactones, in shaping the microbial environment and enhancing plant resilience. Additionally, it addresses modern techniques for analyzing microbial communities, including metagenomics and next-generation sequencing, and their applications in advancing precision agriculture. Future research should focus on bridging knowledge gaps related to genotype-microbiome interactions, exploring emerging microbial consortia and enhancing the integration of microbiome management in precision agriculture systems to improve plant health and productivity.

Microbiome Engineering for Sustainable Rice Production: Strategies for Biofertilization, Stress Tolerance, and Climate Resilience

The plant microbiome, found in the rhizosphere, phyllosphere, and endosphere, is essential for nutrient acquisition, stress tolerance, and the overall health of plants. This review aims to update our knowledge of and critically discuss the diversity and functional roles of the rice microbiome, as well as microbiome engineering strategies to enhance biofertilization and stress resilience. Rice hosts various microorganisms that affect nutrient cycling, growth promotion, and resistance to stresses. Microorganisms carry out these functions through nitrogen fixation, phytohormone and metabolite production, enhanced nutrient solubilization and uptake, and regulation of host gene expression. Recent research on molecular biology has elucidated the complex interactions within rice microbiomes and the signalling mechanisms that establish beneficial microbial communities, which are crucial for sustainable rice production and environmental health. Crucial factors for the successful commercialization of microbial agents in rice production include soil properties, practical environmental field conditions, and plant genotype. Advances in microbiome engineering, from traditional inoculants to synthetic biology, optimize nutrient availability and enhance resilience to abiotic stresses like drought. Climate change intensifies these challenges, but microbiome innovations and microbiome-shaping genes (M genes) offer promising solutions for crop resilience. This review also discusses the environmental and agronomic implications of microbiome engineering, emphasizing the need for further exploration of M genes for breeding disease resistance traits. Ultimately, we provide an update to the current findings on microbiome engineering in rice, highlighting pathways to enhance crop productivity sustainably while minimizing environmental impacts.

Piriformospora indica Mediated Amelioration of Salt Stress in Solanum melongena L. Plants under Greenhouse- A Study on Stomatal Opening/Closure

Salinity is a major abiotic stress that negatively affects agricultural land, significantly reducing crop yields. It alters the fundamental structure of the soil, causing a decrease in porosity, reduced aeration, and impaired water movement. Piriformospora indica, multifaceted fungi can enhance plant tolerance under abiotic stress conditions. The present study examined the effects of Piriformospora indica on the growth of Solanum melongena L. under saline conditions in a greenhouse, assessing parameters such as proline accumulation, lipid peroxidation, chlorophyll content, stomatal behavior, antioxidant activity, and phenotypic traits under salt stress Results of the present study showed significant improvement in phenotypic traits of Piriformospora indica colonized plants under saline conditions. Solanum melongena L. plants treated with 200 mM NaCl had swollen, deformed guard cells and closed stomata, while colonized plants maintained normal stomatal structure and their stomata remained open. Additionally, untreated plants exhibited higher malondialdehyde levels, indicating greater lipid peroxidation, while Piriformospora indica-colonized plants showed reduced oxidative damage, increased chlorophyll content, and enhanced peroxidase activity under saline conditions. The salt tolerance mediated by Piriformospora indica likely involves lipid desaturation, activation of antioxidant enzymes to counter reactive oxygen species, enhanced metabolism, improved nutrient uptake, proline accumulation, and increased phytohormone production.

Development, Shelf Stability, and In-Vitro Evaluation of Liquid Bacterial Inoculant Acinetobacter lwoffii Strain PAU_31LN.

Acinetobacter has been recognized as a versatile plant growth promoting (PGP) rhizobacteria (PGPR) that produce multiple PGP traits. The present study was conducted to formulate an efficient and stable liquid bacterial inoculant (LBI) of Acinetobacter lwoffii strain PAU_31LN. In the current investigation, total 16 endophytic bacteria were isolated from cotton leaves and evaluated for plant growth-promoting features such as production of phytohormones, mineral solubilization, siderophore production, hydrogen cyanide (HCN) production, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. The leaf endophytic bacteria designated as 31LN was found promising for all the PGP traits and it was identified as A. lwoffii strain PAU_31LN by 16S rRNA gene sequencing. For the development of LBI of A. lwoffii strain PAU_31LN, 4.5 g/L yeast extract, 5 g/L NaCl, 5 g/L peptone, and 12.5 mM food-grade trehalose was optimized as appropriate medium composition using response surface methodology (RSM) and Box-Behnken design. Further, the viability of A. lwoffii strain PAU_31LN in the optimized formulation was observed as 1.1 folds higher over the control after 180 days of storage at room temperature. Moreover, nonsignificant variation was recorded in the functional traits of 180 days old LBI of A. lwoffii strain PAU_31LN and freshly prepared LBI. The in-vitro plant growth parameters such as length and seed vigor index of 7-day-old cotton seedlings were enhanced by the seed bio-priming with LBI of A. lwoffii strain PAU_31LN over the control. The results of the present study signify the importance of endophytes and statistical methods to formulate prominent LBI.

A Study of the Different Strains of the Genus Azospirillum spp. on Increasing Productivity and Stress Resilience in Plants.

One of the most important and essential components of sustainable agricultural production is biostimulants, which are emerging as a notable alternative of chemical-based products to mitigate soil contamination and environmental hazards. The most important modes of action of bacterial plant biostimulants on different plants are increasing disease resistance; activation of genes; production of chelating agents and organic acids; boosting quality through metabolome modulation; affecting the biosynthesis of phytochemicals; coordinating the activity of antioxidants and antioxidant enzymes; synthesis and accumulation of anthocyanins, vitamin C, and polyphenols; enhancing abiotic stress through cytokinin and abscisic acid (ABA) production; upregulation of stress-related genes; and the production of exopolysaccharides, secondary metabolites, and ACC deaminase. Azospirillum is a free-living bacterial genus which can promote the yield and growth of many species, with multiple modes of action which can vary on the basis of different climate and soil conditions. Different species of Bacillus spp. can increase the growth, yield, and biomass of plants by increasing the availability of nutrients; enhancing the solubilization and subsequent uptake of nutrients; synthesizing indole-3-acetic acid; fixing nitrogen; solubilizing phosphorus; promoting the production of phytohormones; enhancing the growth, production, and quality of fruits and crops via enhancing the production of carotenoids, flavonoids, phenols, and antioxidants; and increasing the synthesis of indoleacetic acid (IAA), gibberellins, siderophores, carotenoids, nitric oxide, and different cell surface components. The aim of this manuscript is to survey the effects of Azospirillum spp. and Bacillus spp. by presenting case studies and successful paradigms in several horticultural and agricultural plants.

Applying microbial biostimulants and drought-tolerant genotypes to enhance barley growth and yield under drought stress.

With climate change, the frequency of regions experiencing water scarcity is increasing annually, posing a significant challenge to crop yield. Barley, a staple crop consumed and cultivated globally, is particularly susceptible to the detrimental effects of drought stress, leading to reduced yield production. Water scarcity adversely affects multiple aspects of barley growth, including seed germination, biomass production, shoot and root characteristics, water and osmotic status, photosynthesis, and induces oxidative stress, resulting in considerable losses in grain yield and its components. In this context, the present review aims to underscore the importance of selecting drought-tolerant barley genotypes and utilizing bio-inoculants constructed from beneficial microorganisms as an agroecological approach to enhance barley growth and production resilience under varying environmental conditions. Selecting barley genotypes with robust physiological and agronomic tolerance can mitigate losses under diverse environmental conditions. Plant Growth Promoting Rhizobacteria (PGPR) play a crucial role in promoting plant growth through nutrient solubilization, nitrogen fixation, phytohormone production, exopolysaccharide secretion, enzyme activity enhancement, and many other mechanisms. Applying drought-tolerant genotypes with bio-inoculants containing PGPR, improves barley's drought tolerance thereby minimizing losses caused by water scarcity.

Symbiosis vs pathogenesis in plants: Reflections and perspectives.

Plant-microbe partnerships constitute a complex and intricately woven network of connections that have evolved over countless centuries, involving both cooperation and antagonism. In various contexts, plants and microorganisms engage in mutually beneficial partnerships that enhance crop health and maintain balance in ecosystems. However, these associations also render plants susceptible to a range of pathogens. Understanding the fundamental molecular mechanisms governing these associations is crucial, given the notable susceptibility of plants to external environmental influences. Based on quorum sensing signals, phytohormone, and volatile organic carbon (VOC) production and others molecules, microorganisms influence plant growth, health, and defense responses. This review explores the multifaceted relationships between plants and their associated microorganisms, encompassing mutualism, commensalism, and antagonism. The molecular mechanisms of symbiotic and pathogenic interactions share similarities but lead to different outcomes. While symbiosis benefits both parties, pathogenesis harms the host. Genetic adaptations optimize these interactions, involving coevolution driving process. Environmental factors influence outcomes, emphasizing the need for understanding and manipulation of microbial communities for beneficial results. Research directions include employing multi-omics techniques, functional studies, investigating environmental factors, understanding evolutionary trajectories, and harnessing knowledge to engineer synthetic microbial consortia for sustainable agriculture and disease management.

Antagonistic Efficacy of Native Trichoderma Isolates Against Agricultural Plant Pathogens in India

Biological control agents (BCAs) becoming a key element of sustainable agriculture, which maintain ecological balance and shows antagonism against many major problematic plant diseases of world. It is considered as natural and environmentally acceptable alternative to chemical pesticide (Baker and Paulitz, 1996). Different species of Trichoderma used in agricultural fields act against large number of phytopathogens. It also helpful in plant growth–promotion, uptake of nutrition from the soil by mineral solubilization, the secretion of secondary metabolites, and production of phytohormones. Some species play important roles in biofortification, bioremediation, and phytoremediation, as well as contaminants from the environment.

Protease and Phytohormone Production by Potassium solubilizers Isolated from Maize Rhizosphere

Protease and Phytohormone Production by Potassium solubilizers Isolated from Maize Rhizosphere

Is Pseudofrankia, the non-nitrogen-fixing and/or non-nodulating actinorhizal nodule dweller, mutualistic or parasitic? Insights from genome-predictive analysis.

This study re-evaluates Pseudofrankia strains, traditionally regarded as parasitic dwellers of actinorhizal root nodules due to their inability to fix nitrogen (Fix -) and/or nodulate (Nod -), as potential plant growth-promoting bacteria (PGPB). We compared plant growth-promoting traits (PGPTs) between Pseudofrankia strains, including one newly sequenced strain BMG5.37 in this study and typical (Fix + /Nod +) Frankia, Protofrankia, and Parafrankia, as well as non-frankia actinorhizal species Nocardia and Micromonospora, and the phytopathogenic Streptomyces. Although lacking nitrogen-fixing genes typically found in mutualistic Frankiaceae strains, Pseudofrankia may compensate through predicted pathways for denitrification and nitrate utilization. Functional profiling suggests potential for phosphorus solubilization, gibberellin production, and vitamin metabolism, as well as bioremediation of pollutants. Pseudofrankia strains are predicted to show moderate resistance to heavy metals, with a stronger tolerance to arsenic and tellurium compared to Frankia. Furthermore, they are anticipated to exhibit significant biotic and abiotic stress resistance, including oxidative and osmotic stress. Predictive data also indicate that Pseudofrankia strains may have root colonization abilities and may play a role in plant signaling and phytohormone production, particularly in auxin and gibberellin pathways. Secretion systems, especially CE-Type VI, are predicted to be highly developed in Pseudofrankia, suggesting potential for effective plant interactions. These findings position Pseudofrankia strains as promising candidates for plant growth promotion, although experimental validation and the integration of transcriptomic or proteomic data are needed to confirm these predictions.

The Role of Bacillus sp. in Reducing Chemical Inputs for Sustainable Crop Production

Bacillus species have emerged as promising agents for reducing chemical input in sustainable crop production. These bacteria possess diverse abilities, including nutrient cycling, phytohormone production, and stress tolerance enhancement in plants. Recent advances in omics technologies have revolutionized the understanding of Bacillus sp. biology and expanded their potential applications. Bacillus-based products have demonstrated effectiveness in reducing nitrogen and phosphorus fertilizer requirements while maintaining or improving crop yields. However, their field performance may be inconsistent, highlighting the need for further research to optimize formulations and delivery methods. The compatibility with other agricultural inputs varies depending on the specific chemicals and conditions involved. The introduction of Bacillus sp. can significantly affect the soil microbiome, potentially promoting plant growth and microbial diversity. Strain specificity and host compatibility play crucial roles in determining the success of host–parasite interactions. The regulatory and safety aspects require further investigation to ensure the safe and sustainable use of Bacillus species in various applications. The integration of Bacillus-based products into existing crop management systems, following the principles of Integrated Pest Management and Integrated Crop Management, is essential for their successful implementation. This review provides a comprehensive overview of the current knowledge on Bacillus sp. for reducing chemical inputs for sustainable crop production, highlighting the challenges and opportunities for future research and application.

Molecular Communication of Microbial Plant Biostimulants in the Rhizosphere Under Abiotic Stress Conditions.

Microbial plant biostimulants offer a promising, sustainable solution for enhancing plant growth and resilience, particularly under abiotic stress conditions such as drought, salinity, extreme temperatures, and heavy metal toxicity. These biostimulants, including plant growth-promoting rhizobacteria, mycorrhizal fungi, and nitrogen-fixing bacteria, enhance plant tolerance through mechanisms such as phytohormone production, nutrient solubilization, osmotic adjustment, and antioxidant enzyme activation. Advances in genomics, metagenomics, transcriptomics, and proteomics have significantly expanded our understanding of plant-microbe molecular communication in the rhizosphere, revealing mechanisms underlying these interactions that promote stress resilience. However, challenges such as inconsistent field performance, knowledge gaps in stress-related molecular signaling, and regulatory hurdles continue to limit broader biostimulant adoption. Despite these challenges, microbial biostimulants hold significant potential for advancing agricultural sustainability, particularly amid climate change-induced stresses. Future studies and innovation, including Clustered Regularly Interspaced Short Palindromic Repeats and other molecular editing tools, should optimize biostimulant formulations and their application for diverse agro-ecological systems. This review aims to underscore current advances, challenges, and future directions in the field, advocating for a multidisciplinary approach to fully harness the potential of biostimulants in modern agriculture.

Wild again: recovery of a beneficial Cannabis seed endophyte from low domestication genotypes

BackgroundBeyond carrying the plant embryo, seeds harbour intricate microbial communities whose transmission across successive plant generations can significantly influence the ecological and evolutionary dynamics of plant–microbe symbioses. The process of plant domestication has potential repercussions in genes involved in plant-microbiome interactions. However, the extent to which breeding can impact the seed microbiome is sparsely explored. Cannabis is a high-value crop but sparsely subjected to agricultural innovations established in other crop species during the last century. Here, we conduct a large-scale analysis of the bacterial seed microbiome of Cannabis across different domestication grades and investigate the potential of seed-associated endophytes as plant growth-promoting agents under both controlled and field conditions.ResultsAnalysis of Cannabis seed endophyte composition and diversity across 46 plant genotypes revealed 813 different bacterial genera with a predominance of Gammaproteobacteria, Bacilli, Actinobacteria and Alphaproteobacteria but a genotype-specific microbiome. The assessment of domestication and breeding on microbial assembly revealed a higher bacterial diversity in low domestication genotypes (Shannon index, H′: 1.21 vs. 1.05) and a higher homogeneity in bacterial composition caused by line development. Further, a seed bacterial isolate (Bacillus frigoritolerans C1141) associated with low domestication genotypes, and with genes associated with bio-fertilization, bioremediation and phytohormone production, increased plant growth by 42.3% at the time of harvest, under field conditions.ConclusionThis study addresses critical knowledge gaps related to the assembly of the Cannabis seed-endophytic microbiome. It reveals that Cannabis breeding is linked to alterations of seed microbial communities, which potentially led to the loss of bacteria with functional significance. These results highlight the importance of preserving seed microbiomes in plant breeding to support sustainable plant health and growth enhancement in Cannabis.CAHvc7HPtw2foEoMit4yw-Video

Polyurethane waste valorization: A Two-Phase process using Ozonization and Rhodococcus pyridinivorans fermentation for biofertilizer production

A circular economy process has been developed to convert polyurethane waste into biofertilizing microorganisms through a sequential chemical/biological process. The chemical phase involves the complete depolymerization of polyurethane using ozone attack, generating an aqueous extract (OLE) composed of small, bioavailable molecules such as polyols, isocyanate derivatives, and carboxylic acids. The biological phase utilizes OLE for the generation of biomass with biofertilizing functional activity through Rhodococcus pyridinivorans fermentation. The metabolic-proteomic expression during the biodegradation of OLE involves the synthesis of numerous enzymes such as cutinases, hydrolases, proteases, esterases and oxidoreductases, which participate in the degradation of chemical compounds like benzene derivatives, phenols, or plastic polymers. OLE has been converted into microorganisms with biofertilizing properties, including nitrogen fixation, phytohormone production and siderophores. This process contributes to sustainability by diverting polyurethane waste from landfills, reducing the environmental impact of chemical fertilizers and promoting a more sustainable agricultural system.

Effects of chitosan on plant growth under stress conditions: similarities with plant growth promoting bacteria.

The agricultural use of synthetic pesticides, fertilizers, and growth regulators may represent a serious public health and environmental problem worldwide. All this has prompted the exploration of alternative chemical compounds, leading to exploring the potential of chitosan and PGPB in agricultural systems as a potential biotechnological solution to establish novel agricultural production practices that not only result in fewer adverse impacts on health and the environment but also improve the resilience and growth of the plants. In this work, an analysis of the impact of plant growth-promoting bacteria (PGPB) and chitosan on plant growth and protection has been conducted, emphasizing the crucial bioactivities of the resistance of the plants to both biotic and abiotic stressors. These include inducing phytohormone production, mobilization of insoluble soil nutrients, biological nitrogen fixation, ethylene level regulation, controlling soil phytopathogens, etc. Moreover, some relevant aspects of chitin and chitosan are discussed, including their chemical structures, sources, and how their physical properties are related to beneficial effects on agricultural applications and mechanisms of action. The effects of PGPB and chitosan on photosynthesis, germination, root development, and protection against plant diseases have been compared, emphasizing the intriguing similarities and synergistic effects observed in some of these aspects. Although currently there are limited studies focused on the combined application of PGPB and chitosan, it would be important to consider the similarities highlighted in this work, and those that may emerge in future studies or through well-designed investigations, because these could permit advancing towards a greater knowledge of these systems and to obtain better formulations by combining these bioproducts, especially for use in the new contexts of sustainable agriculture. Thus, it seems feasible to augur a promising near future for these combinations, considering the wide range of possibilities offered by chitinous biomaterials for the development of innovative formulations, as well as allowing different application methods. Likewise, the studies related to the PGPB effects on plant growth appear to be expanding due to ongoing research to test on plants the impacts of microorganisms derived from different environments, whether known or recently discovered, making it a very exciting field of research.

A study on the potential of endophytic bacteria to promote plant growth: uses in agriculture and future directions

The escalating demand for chemical-free fertilizers in agriculture stems from the adverse impacts associated with chemical fertilizers on both human and animal health, as well as environmental pollution. To address this concern, plant-based microorganisms emerge as a promising solution for the development of environmentally sustainable biofertilizers. Among these microorganisms, endophytic bacteria, residing within plant tissues without causing harm to the host plant, exhibit exceptional attributes conducive to plant growth promotion. Notably, these bacteria demonstrate the production of phytohormones, ammonia, phosphate solubilization, and nitrogen fixation capabilities. Additionally, endophytic bacteria showcase the synthesis of hydrolytic enzymes, the production of siderophores, and antimicrobial activity against pathogens. Such characteristics contribute significantly to the robust growth and development of host plants, fostering tolerance to environmental stresses. This manuscript aims to comprehensively review the plant growth promotion activities of endophytic bacteria, elucidating their diversity and isolation from various plants. Furthermore, it explores the potential future directions in this burgeoning field of research, envisioning the development of endophytic bacterial strains capable of replacing traditional chemical fertilizers. Future research endeavors hold the promise of uncovering novel and effective endophytic bacterial strains, heralding a sustainable paradigm shift in the realm of agricultural fertilization.

Induction of Two Pseudomonas Strains Indole Acetic Acid Production by Synthetic and Biologically-Produced L-Tryptophan: a Comparative Study

Amino acids, serving as fundamental building blocks of proteins, can also act as inducers in essential metabolic pathways across various microorganisms. The metabolic effects of synthetic and biologically produced amino acid L-tryptophan on two Pseudomonas strains – Pseudomonas chlororaphis 1S4 and Pseudomonas yamanorum 1046 were compared in this study. Both strains belong to the plant growth-pro¬moting rhizobacteria. The inducers impacted the production of the primary auxin phytohormone in the plant kingdom, the indole-3-acetic acid. The biologically produced L-tryptophan exerted a more pronounced positive effect on its production in both strains, increasing the process efficiency.

Ecological Diversity of Lycopersicon esculentum (Tomato) Root Associated Plant Growth Promoting Rhizobacteria (PGPRs)

Tomato member of family Solanaceae is one amongst the foremost important vegetable crop worldwide. It has its significance due to its nutritive, therapeutic and antioxidant properties. An ecofriendly approach to improve the crop yield is the use of PGPRs which improves the growth of plant through nitrogen fixation, phosphorus solubilization and phyto-hormone production. The present study is to evaluate the biodiversity of such PGPRs and their potential role as biofertilizer for tomato crop. A total eight bacteria were isolated and purified from soil and rhizosphere of tomato plant collected from temperate and tropical rainfed regions of Pakistan including Rawalakot and Attock respectively. Soil texture of Rawalakot and Attock varied from sandy loam to loamy. Plant growth promoting traits like N2 Fixation, P-solubilization and IAA production were determined for all the eight isolates. Maximum P-solubilization was shown by isolates from Attock, AS4 (129.72 µg mL-1) and Rawalakot, RS3 (132.73 µg mL-1) and maximum IAA production was observed in Rawalakot isolates, RS2 (22.237 µg mL-1) followed by Attock isolates, AS3 (49.63 µg mL-1) and AS2 (62.86 µg mL-1). PGPRs were selected with multifunctional properties and were used in plant inoculation experiment to study enhanced growth of tomato plants. Bacterial isolates showed remarkable increase in all growth parameters as compare to uninoculated control. These PGPRs can be best developed for improved development of tomato plants with less dependence on chemical fertilizers.

Bacillus licheniformisYB06: A Rhizosphere-Genome-Wide Analysis and Plant Growth-Promoting Analysis of a Plant Growth-Promoting Rhizobacterium Isolated from Codonopsis pilosula.

Codonopsis pilosula, commonly known as Dangshen, is a valuable medicinal plant, but its slow growth and susceptibility to environmental stress pose challenges for its cultivation. In pursuit of sustainable agricultural practices to enhance the yield and quality of Dangshen, the present study isolated a bacterial strain exhibiting plant growth-promoting potential from the rhizosphere of C. pilosula. This strain was subsequently identified as Bacillus licheniformisYB06. Assessment of its plant growth-promoting attributes revealed the potential of B. licheniformis YB06 as a biofertilizer. Whole-genome sequencing of B. licheniformis YB06 revealed a genome size of 4,226,888 bp with a GC content of 46.22%, harboring 4325 predicted protein-coding sequences. Genomic analysis of B. licheniformis YB06 revealed a diverse array of genes linked to induced systemic resistance (ISR) and plant growth-promoting (PGP) traits, encompassing phytohormone production, nitrogen assimilation and reduction, siderophore biosynthesis, phosphate solubilization, biofilm formation, synthesis of PGP-related amino acids, and flagellar motility. Seed germination assays demonstrated the positive effects of B. licheniformis YB06 on the germination and growth of C. pilosula seedlings. Furthermore, we explored various fertilization regimes, particularly the B. licheniformis YB06-based biofertilizer, were investigated for their impact on the structure and diversity of the C. pilosula rhizosphere soil bacterial community. Our findings revealed that fertilization significantly impacted soil bacterial composition and diversity, with the combined application of B. licheniformis YB06-based biofertilizer and organic fertilizer exhibiting a particularly pronounced enhancement of rhizosphere bacterial community structure and diversity. This study represents the first report on the beneficial effects of B. licheniformis YB06 on both the growth of C. pilosula and the composition of its rhizosphere soil microbial community. These findings provide a theoretical foundation and practical guidance for the development of novel bio-organic compound fertilizers, thereby contributing to the sustainable cultivation of C. pilosula.

Bacterial allelopathy: an approach for biological control of weeds.

Weed infestation is one of the most damaging biotic factors to limit crop production by competing with the crop for space, water, and nutrients. Different conventional approaches are being used to cope with weed infestation, including labor intensive manual removal and the use of soil-degrading, crop-damaging, and environment-deteriorating chemical herbicides. The use of chemicals for weed control has increased 2-fold after the green revolution and their non-judicious use is posing serious threats to mankind, animals, and biodiversity. The detrimental effects of these approaches have shifted the researchers' attention from the last two decades towards alternate, sustainable, and eco-friendly approaches to cope with weed infestation. The recent approaches of weed control, including plant and microbial allelopathy have gained popularity during last decade. Farmers still use conventional methods, but the majority of farmers are very passionate about organic agriculture and describe it as a slogan in the developed world. The effectiveness of these approaches lies in host specificity by selective bacteria and differential response towards weeds and crops. Moreover, the crop growth promoting effect of microorganisms (allelopathic bacteria) possessing various growth promoting traits, that is, mineral solubilization, phytohormone production, and beneficial enzymatic activity, provide additional benefits. The significance of this review lies in the provision of a comprehensive comparison of the conventional approaches along with their potential limitations with advanced/biological weed control approaches in sustainable production. In addition, the knowledge imparted about weed control will contribute to a better understanding of biological control methods.