Mechanisms Of Plant Growth Promotion Research Articles

Plant growth-promoting mechanisms and genetic diversity of bacteria strains isolated from Brachiaria humidicola and Brachiaria decumbens.

Plant growth-promoting bacteria (PGPB) have received great interest in recent decades. However, PGPB mechanisms remain poorly understood in forage species. We aimed to evaluate roots endophytic and rhizospheric bacteria strains from Brachiaria humidicola and Brachiaria decumbens. The strains were evaluated for biological nitrogen-fixing in saline stress (0 to 10.0 g L-1 of NaCl), N-acyl homoserine lactones and indole-like compounds (ILC) production, the activity of hydrolytic enzymes, and inorganic phosphate solubilization (IPS) under different C sources. The diversity of strains was assessed by BOX-PCR. About 58% of strains were positive for BNF. High salinity levels reduced the growth and BNF. About 58% produced N-acyl homoserine lactones. The ILC was present in 39% of strains. Cellulase, polygalacturonase, pectate lyase, and amylase production were observed in 77, 14, 22, and 25% of strains, respectively. The IPS was observed in 44, 81, and 87% of isolates when glucose, mannitol and sucrose were used, respectively. Comparing two plant species and niches, the strains associated with B. humidicola and root endophytic presented more PGPB mechanisms than others. We found high strain diversity, of which 64% showed similarity lower than 70%. These results can be supporting the bioproducts development to increase forage grasses production in tropical soils.

Mechanism of Plant Growth Promotion and Disease Suppression by Chitosan Biopolymer

The chitosan (CHT) biopolymer is a de-acetylated chitin derivative that exists in the outer shell of shrimp, shellfish, lobster or crabs, as well as fungal cell walls. Because of its biodegradability, environmental non-toxicity, and biocompatibility, it is an ideal resource for sustainable agriculture. The CHT emerged as a promising agent used as a plant growth promoter and also as an antimicrobial agent. It induces plant growth by influencing plant physiological processes like nutrient uptake, cell division, cell elongation, enzymatic activation and synthesis of protein that can eventually lead to increased yield. It also acts as a catalyst to inhibit the growth of plant pathogens, and alter plant defense responses by triggering multiple useful metabolic pathways. This review emphasizes the role and mechanisms of CHT as a plant growth promoter and disease suppressor, and its future implications in agriculture.

Analysis of the Interaction between Pisum sativum L. and Rhizobium laguerreae Strains Nodulating This Legume in Northwest Spain.

Pisum sativum L. (pea) is one of the most cultivated grain legumes in European countries due to the high protein content of its seeds. Nevertheless, the rhizobial microsymbionts of this legume have been scarcely studied in these countries. In this work, we analyzed the rhizobial strains nodulating the pea in a region from Northwestern Spain, where this legume is widely cultivated. The isolated strains were genetically diverse, and the phylogenetic analysis of core and symbiotic genes showed that these strains belong to different clusters related to R. laguerreae sv. viciae. Representative strains of these clusters were able to produce cellulose and cellulases, which are two key molecules in the legume infection process. They formed biofilms and produced acyl-homoserine lactones (AHLs), which are involved in the quorum sensing regulation process. They also exhibited several plant growth promotion mechanisms, including phosphate solubilization, siderophore, and indole acetic acid production and symbiotic atmospheric nitrogen fixation. All strains showed high symbiotic efficiency on pea plants, indicating that strains of R. laguerreae sv. viciae are promising candidates for the biofertilization of this legume worldwide.

Isolates of Bacillus sp. from garlic: effect on corn development and plant growth-promoting mechanisms

Corn and garlic are important crops to Curitibanos region (state of Santa Catarina – Brazil), often planted in alternate cropping seasons. Production costs are high, especially due to N fertilizer, since they are highly demanding in N. In addition to reducing economic costs, the search for environmentally sustainable technologies has stimulated the study of interactions between plants and growth-promoting microorganisms. Rhizobacteria, e.g., Bacillus sp., have been presenting as growth-promoting microorganisms. Five isolates of garlic rhizosphere from 27 individuals of [...]

Use of Plant Growth-Promoting Rhizobacteria in Maize and Sugarcane: Characteristics and Applications

Free-living bacteria that actively colonize plant roots and provide positive effects on plant development are called plant-growth promoting. Plant growth-promoting bacteria can promote plant growth and use their own metabolism to solubilize phosphates, produce hormones and fix nitrogen, and they can directly affect plant metabolism. PGPR also increase plant absorption of water and nutrients, improving root development and increasing plant enzymatic activity; moreover, PGPR can promote other microorganisms as part of a synergistic effect to improve their effects on plants, promoting plant growth or suppressing pathogens. Many studies have shown several benefits of the use of PGPR in maize and sugarcane crops. These bacteria are an excellent alternative to farmers to reduce chemical fertilization and pesticide input without promoting the environment impact and yield-reducing. The present review is an effort to elucidate the concept of rhizobacteria in the current scenario and their underlying mechanisms of plant growth promotion with recent updates. The latest paradigms of a wide range of applications of these beneficial rhizobacteria in both crops maize and sugarcane have been presented explicitly to garner broad perspectives regarding their functioning and applicability. The results from several studies have shown that the utilization of PGPR in maize and sugarcane is the great alternative to farmers face the challenge the modern agriculture.

Diazotrophic bacteria from maize exhibit multifaceted plant growth promotion traits in multiple hosts.

Sierra Mixe maize is a geographically remote landrace variety grown on nitrogen-deficient fields in Oaxaca, Mexico that meets its nutritional requirements without synthetic fertilizer by associating with free-living diazotrophs comprising the microbiota of its aerial root mucilage. We selected nearly 500 diazotrophic (N2-fixing) bacteria isolated from Sierra Mixe maize mucilage and sequenced their genomes. Comparative genomic analysis demonstrated that isolates represented diverse genera and composed three major diazotrophic groups based on nitrogen fixation gene content. In addition to nitrogen fixation, we examined deamination of 1-amino-1-cyclopropanecarboxylic acid, biosynthesis of indole-3-acetic acid, and phosphate solubilization as alternative mechanisms of direct plant growth promotion (PGP). Genome mining showed that isolates of all diazotrophic groups possessed marker genes for multiple mechanisms of direct plant growth promotion (PGP). Implementing in vitro assays corroborated isolate genotypes by measuring each isolate’s potential to confer the targeted PGP traits and revealed phenotypic variation among isolates based on diazotrophic group assignment. Investigating the ability of mucilage diazotrophs to confer PGP by direct inoculation of clonally propagated potato plants in planta led to the identification of 16 bio-stimulant candidates. Conducting nitrogen-stress greenhouse experiments demonstrated that potato inoculation with a synthetic community of bio-stimulant candidates, as well as with its individual components, resulted in PGP phenotypes. We further demonstrated that one diazotrophic isolate conferred PGP to a conventional maize variety under nitrogen-stress in the greenhouse. These results indicate that, while many diazotrophic isolates from Sierra Mixe maize possessed genotypes and in vitro phenotypes for targeted PGP traits, a subset of these organisms promoted the growth of potato and conventional maize, potentially through the use of multiple promotion mechanisms.

Complete Genome Sequence of Rahnella aquatilis MEM40, a Plant Growth-Promoting Rhizobacterium Isolated from Rice Rhizosphere Soil, with Antagonism against Magnaporthe oryzae and Fusarium graminearum.

Rahnella aquatilis strain MEM40 is a plant growth-promoting rhizobacterium (PGPR) with antagonism against Magnaporthe oryzae and Fusarium graminearum that was isolated from rice rhizosphere soil in Hubei, China. Here, we report its complete genome sequence, which will increase our understanding of the mechanisms of plant growth promotion and biocontrol.

Rhizobium laguerreae Improves Productivity and Phenolic Compound Content of Lettuce (Lactuca sativa L.) under Saline Stress Conditions.

Lettuce (Lactuca sativa L.) is a widely consumed horticultural species. Its significance lies in a high polyphenolic compound content, including phenolic acids and flavonols. In this work, we have probed the ability of Rhizobium laguerreae HUTR05 to promote lettuce growth, under in vitro and greenhouse conditions (both non-saline and saline conditions). This strain has shown several in vitro plant growth promotion mechanisms, as well as capacity to colonize lettuce seedlings roots. We have analyzed the effect of the rhizobacterium inoculation on mineral and bioactive compounds in lettuce, under greenhouse conditions, and found a rise in the content of certain phenolic acids and flavonoids, such as derivatives of caffeoyl acid and quercetin. The genome analysis of the strain has shown the presence of genes related to plant growth-promoting rhizobacteria (PGPR) mechanisms, defense from saline stress, and phenolic compound metabolism (such as naringenin-chalcone synthase or phenylalanine aminotransferase).

Native rhizobia from southern Brazilian grassland promote the growth of grasses

Soil communities support great biodiversity, as well as their interaction with the plants, can be equally diverse. In this work, we focused our attention on investigating the effect of native rhizobia from Brazilian grassland as a plant growth-promoting rhizobacteria for grasses. We suggest that the positive effect of rhizobacteria on plants is context-dependent, and native species may present better adaptability under certain soil conditions (i.e. acidity, nutrient availability, interaction with other organisms in the rhizosphere). To explore this iteration among native rhizobia and grasses, we isolated rhizobia from Desmodium incanum, a native legume from Brazilian grassland, and inoculated on oats (Avena sativa) and maize (Zea mays). Firstly, we characterized the ability of those rhizobia in solubilizing phosphate and producing indole-acetic acid. Next, under greenhouse conditions, we inoculated grasses with the isolates that presented at least one mechanism of plant growth promotion. After 45 days, we measured the effect of those rhizobia on both morphological and nutritional attributes of grasses. Our finding showed that rhizobia isolated from Desmodium incanum improve the growth of grasses by increasing shoot and root biomass, plant height, and nutrient accumulation in leaves. The most efficient isolate was UFRGS-Dinc1, perhaps due to its ability in solubilize phosphate and produce indole-acetic acid. However, we also noted that UFRGS-Dinc3, that presented the highest phosphate solubilization index, and UFRGS-Dinc18, that produce only indole-acetic acid, could also promote plant growth of grasses. Our results provide pieces of evidence that native rhizobia from Desmodium incanum can promote the growth of grasses, indicating their potential in increasing the yield of crop cultures.

Pan-genome analysis of Paenibacillus polymyxa strains reveals the mechanism of plant growth promotion and biocontrol.

Rapid development of gene sequencing technologies has led to an exponential increase in microbial sequencing data. Genome research of a single organism does not capture the changes in the characteristics of genetic information within a species. Pan-genome analysis gives us a broader perspective to study the complete genetic information of a species. Paenibacillus polymyxa is a Gram-positive bacterium and an important plant growth-promoting rhizobacterium with the ability to produce multiple antibiotics, such as fusaricidin, lantibiotic, paenilan, and polymyxin. Our study explores the pan-genome of 14 representative P. polymyxa strains isolated from around the world. Heap's law model and curve fitting confirmed an open pan-genome of P. polymyxa. The phylogenetic and collinearity analyses reflected that the evolutionary classification of P. polymyxa strains are not associated with geographical area and ecological niches. Few genes related to phytohormone synthesis and phosphate solubilization were conserved; however, the nif cluster gene associated with nitrogen fixation exists only in some strains. This finding is indicative of nitrogen fixing ability is not stable in P. polymyxa. Analysis of antibiotic gene clusters in P. polymyxa revealed the presence of these genes in both core and accessory genomes. This observation indicates that the difference in living environment led to loss of ability to synthesize antibiotics in some strains. The current pan-genomic analysis of P. polymyxa will help us understand the mechanisms of biological control and plant growth promotion. It will also promote the use of P. polymyxa in agriculture.

Enhanced growth in nursery of coffee seedlings inoculated with the rhizosphere fungus Aspergillus niger for field transplantation

Multifunctional microorganisms, showing multiple mechanisms of plant growth promotion, are desirable in the development of microbial formulations. Aspergillus niger is known for its capacity to solubilize mineral phosphates, being considered a promising candidate for the development of inoculants. Furthermore, A. niger can produce phytohormones, which places it as a potential multifunctional plant-growth promoter. To test this potential, we evaluated if A. niger can promote the growth of coffee (Coffea arabica L.) seedlings in a substrate with no P limitation. The seedlings inoculated with a granular formulation of A. niger presented significant increments in height (5.6%), stem diameter (6.1%), number of leaves (8.5%), and root dry mass (13%) and volume (15%) after 30 weeks. These findings show that A. niger can promote the growth of coffee seedlings in a substrate with no P limitation, providing evidence that A. niger has additional plant growth-promotion traits.

Bacillus pumilus LZP02 Promotes Rice Root Growth by Improving Carbohydrate Metabolism and Phenylpropanoid Biosynthesis.

Elucidation of the underlying mechanisms of plant growth promotion of rhizobacteria is very important. This study explored the mechanism by which Bacillus pumilus LZP02 promotes growth in rice roots through proteomic, transcriptomic, and metabolomic techniques. The results showed that B. pumilus LZP02 promoted the absorption of phosphorous, calcium, and magnesium ions by colonization of rice roots and enhanced peroxidase, catalase, superoxide dismutase, and Ca2+Mg2+ adenosine triphosphatase activities and chlorophyll contents in rice. The proteomic results showed that most of the differentially expressed proteins were involved in carbohydrate metabolism and that the biosynthesis of other secondary metabolites was also increased. According to RNA-seq and reverse transcription-quantitative PCR analyses, expression of some genes involved in carbohydrate metabolism and phenylpropanoid biosynthesis was upregulated in rice roots. Regarding metabolomics, phenylpropanoid biosynthesis, starch and sucrose metabolism, the pentose phosphate pathway, and glyoxylate and dicarboxylate metabolism were increased. The results indicated that B. pumilus LZP02 promoted the growth of rice roots by enhancing carbohydrate metabolism and phenylpropanoid biosynthesis.

Mechanisms in plant growth-promoting rhizobacteria that enhance legume-rhizobial symbioses.

Nitrogen fixation is an important biological process in terrestrial ecosystems and for global crop production. Legume nodulation and N2 fixation have been improved using nodule-enhancing rhizobacteria (NER) under both regular and stressed conditions. The positive effect of NER on legume-rhizobia symbiosis can be facilitated by plant growth-promoting (PGP) mechanisms, some of which remain to be identified. NER that produce aminocyclopropane-1-carboxylic acid deaminase and indole acetic acid enhance the legume-rhizobia symbiosis through (i) enhancing the nodule induction, (ii) improving the competitiveness of rhizobia for nodulation, (iii) prolonging functional nodules by suppressing nodule senescence and (iv) upregulating genes associated with legume-rhizobia symbiosis. The means by which these processes enhance the legume-rhizobia symbiosis is the focus of this review. A better understanding of the mechanisms by which PGP rhizobacteria operate, and how they can be altered, will provide opportunities to enhance legume-rhizobial interactions, to provide new advances in plant growth promotion and N2 fixation.

Bacillus strain selection with plant growth-promoting mechanisms as potential elicitors of systemic resistance to gray mold in pepper plants.

Certain soil bacteria produce beneficial effects on the growth and health of plants; hence, their use is steadily increasing. Five strains of Bacillus with plant growth-promoting potential were selected in this study, which produced indole-3-acetic acid levels below 50µg.mL-1. On the other hand, while only strains M8 and M15 dissolved phosphorus, the latter was the only strain that did not produce siderophores. Only strains M8 and M16 significantly inhibited the in vitro growth of Botrytis cinerea and Fusarium solani phytopathogens, whose inhibition ranges fluctuated between 60% and 63% for strains M8 and M16 against B. cinerea and between 40% and 53% for strains M8 and M16 against F. solani. Based on these results, the need to implement resistance induction against gray mold on pepper plants was determined using strains M8 and M16. In this case, strain M16 inhibited the propagation of the necrotic spot by approximately 70%, whereas strain M8 significantly reduced the superoxide dismutase activity in systemic leaves, which substantially increased in plants inoculated with strain M8 and infected with the pathogen. Accordingly, the use of native rhizobacteria may entail biotechnological progress for the integrated management of crops in agriculture industry.

Bacillus toyonensis COPE52 Modifies Lipid and Fatty Acid Composition, Exhibits Antifungal Activity, and Stimulates Growth of Tomato Plants Under Saline Conditions.

Salinity is one of the most important factors that limit the productivity of agricultural soils. Certain plant growth-promoting bacteria (PGPB) have the ability to stimulate the growth of crop plants even under salt stress. In the present study, we analysed the potential of PGPB Bacillus toyonensis COPE52 to improve the growth of tomato plants and its capacity to modify its membrane lipid and fatty acid composition under salt stress. Thus, strain COPE52 increased the relative amount of branched chain fatty acids (15:0i and 16:1∆9) and accumulation of an unknown membrane lipid, while phosphatidylethanolamine (PE) levels decreased during growth with 100 and 200mM NaCl. Importantly, direct and indirect plant growth-promoting (PGP) mechanisms of B. toyonensis COPE52, such as indole-3-acetic acid (IAA), protease activity, biofilm formation, and antifungal activity against Botrytis cinerea, remained unchanged in the presence of NaCl in vitro, compared to controls without salt. In a greenhouse experiment, tomato plants (Lycopersicon esculentum 'Saladette') showed increased shoot and root length, higher dry biomass, and chlorophyll content when inoculated with B. toyonensis COPE52 at 0 and 100mM NaCl. In summary, these results indicate that Bacillus toyonensis COPE52 can modify cell membrane lipid components as a potential protecting mechanism to maintain PGP traits under saline-soil conditions.

Effects of Selected Functional Bacteria on Maize Growth and Nutrient Use Efficiency.

Plant growth-promoting rhizobacteria (PGPR), which include isolates from genera Paraburkholderia, Burkholderia and Serratia, have received attention due to their numerous plant growth-promoting mechanisms such as their ability to solubilize insoluble phosphates and nitrogen-fixation. However, there is a dearth of information on the potential plant growth-promoting effects of these three groups of bacteria on non-legumes such as maize. This study determined the influences of the aforementioned strains on soil properties, maize growth, nutrient uptake and nutrient use efficiency. A pot trial using maize as a test crop was done using a randomized complete block design with 7 treatments each replicated 7 times. The treatments used in this study were: Control (no fertilizer), chemical fertilizer (CF), organic-chemical fertilizers combination without inoculum (OCF) and with inocula consisting of single strains [cellulolytic bacteria (TC), organic fertilizer and chemical fertilizer with N-fixing bacteria (TN), organic fertilizer and chemical fertilizer with P-solubilizing bacteria (TP)) and three-strain inocula (TCNP), respectively. The variables measured included plant growth and nutrient content, soil nutrient content and functional rhizospheric bacterial populations. Paraburkholderia nodosa NB1 and Burkholderia cepacia PB3 showed comparable effects on maize biomass and also improved N and P use efficiencies when compared to full chemical fertilization. Nitrogen-fixing rhizobacteria had a positive effect on above-ground biomass of maize. Paraburkholderia nodosa NB1 improved soil total C and organic matter contents, besides being the only bacterial treatment that improved K use efficiency compared to OCF. The results suggest that P. nodosa NB1 and B. cepacia PB3 have potential usage in bio-fertilizers. In contrast, treatments with Serratia nematodiphila C46d and consortium strains showed poorer maize nutrient uptake and use efficiency than the other single strain treatments. Bacterial treatments generally showed comparable or higher overall N and P use efficiencies than full chemical fertilization. These findings suggest that at least half the amounts of N and P fertilizers could be reduced through the use of combined fertilization together with beneficial bacteria.

Maize growth and yield promoting endophytes isolated into a legume root nodule by a cross-over approach

Rhizobia can colonize the roots of grasses in the Brazilian semiarid region; however, studies to isolate these bacteria for growth promotion of maize via unconventional isolation approaches have not been conducted. This study aimed to isolate, characterize (biochemically and molecularly) and assess the potential of cowpea nodulating/maize associated rhizobia for plant growth promotion. Extracts of surface-disinfected maize root were inoculated onto cowpea seeds in axenic conditions. Rhizobia were isolated and classified by sequencing of the 16 S rRNA and nodC genes, and recA and atpD were specifically assayed for Bradyrhizobium. The in vitro ability of rhizobia to produce auxin and siderophores, solubilize calcium phosphate, exhibit antagonism against the growth of the pathogen Fusarium verticillioides, and undergo endophytic colonization were evaluated. The ability of rhizobia to promote the growth of both potted cowpea and maize and to promote the growth and yield of maize under field conditions was also evaluated. Thirteen isolates were obtained, including six Rhizobium, four Agrobacterium, and three Bradyrhizobium isolates, which exhibited high genetic variability and low similarity with the type strains. All bacteria showed at least one plant growth promotion mechanism. Six bacteria stood out regarding the promotion of maize growth, and one bacterium showed the best performance in cowpea. The results of the field assay with maize indicated that Bradyrhizobium sp. ESA 114 and Rhizobium sp. ESA 116 induced the same maize grain yields as those observed in plants inoculated with the commercial strain of Azospirillum brasilense Ab-V5. Maize harbors a community of putative facultative endophytic rhizobia that are genetically diverse and have the potential to be used in inoculant production.

Endophytic microbes: biodiversity, plant growth-promoting mechanisms and potential applications for agricultural sustainability.

Endophytic microbes are known to live asymptomatically inside their host throughout different stages of their life cycle and play crucial roles inthe growth, development, fitness, and diversification of plants. The plant-endophyte association ranges from mutualism to pathogenicity. These microbes help the host to combata diverse array of biotic and abiotic stressful conditions. Endophytic microbes play a major role in the growth promotion of their host by solubilizing of macronutrients such as phosphorous, potassium, and zinc; fixing of atmospheric nitrogen, synthesizing of phytohormones, siderophores, hydrogen cyanide, ammonia, and act as a biocontrol agent against wide array of phytopathogens. Endophytic microbes are beneficial to plants by directly promoting their growth or indirectly by inhibiting the growth of phytopathogens. Over a long period of co-evolution, endophytic microbes have attained the mechanism of synthesis of various hydrolytic enzymes such as pectinase, xylanases, cellulase, and proteinase which help in the penetration of endophytic microbes into tissues of plants. The effective usage of endophytic microbes in the form of bioinoculants reduce the usage of chemical fertilizers. Endophytic microbes belong to different phyla such as Actinobacteria, Acidobacteria, Bacteroidetes, Deinococcus-thermus, Firmicutes, Proteobacteria, and Verrucomicrobia. The most predominant and studied endophytic bacteria belonged to Proteobacteria followed by Firmicutes and then by Actinobacteria. The most dominant among reported genera in most of the leguminous and non-leguminous plants are Bacillus, Pseudomonas, Fusarium, Burkholderia, Rhizobium, and Klebsiella. In future, endophytic microbes have a wide range of potential for maintaining health of plant as well as environmental conditions for agricultural sustainability. The present review is focused on endophytic microbes, their diversity in leguminous as well as non-leguminous crops, biotechnological applications, and ability to promote the growth of plant for agro-environmental sustainability.

Plant growth enhancement is not a conserved feature in the Caulobacter genus

Species within the Caulobacter genus have been termed ‘hub species’ in the plant microbiome. To understand these interactions, we assessed the interactions between several Caulobacter strains and a common host plant. We identified a set of 11 Caulobacter strains that range in genetic diversity and tested them for their ability to increase the growth of Arabidopsis thaliana. In addition, biochemical assays were employed to determine if these Caulobacter strains produce common plant growth promoting (PGP) biosynthates. To identify potential PGP-related genes, genomic analyses were performed to compare the genomes of PGP Caulobacter strains to those of non-PGP Caulobacter strains. For the PGP Caulobacter strains, we observed that common PGP biosynthates did not contribute to the observed Caulobacter-mediated plant growth stimulation. Genomic analyses suggested that the genomes of PGP strains maintain similar metabolic pathways compared to those of non-PGP strains, and that common genes related to PGP factors do not explain the PGP mechanisms for the Caulobacter strains we analyzed. Plant growth enhancement is not a conserved feature in the Caulobacter genus, and some Caulobacter strains even inhibit plant growth. Moreover, common PGP factors do not fully explain Caulobacter-mediated plant growth enhancement.

Biocontrol Potential and Growth Promotion Capability of Bacillus sp. LBF-1 for Management of Wilt Disease of Solanum lycopersicum Caused by Fusarium sp.

The aim of the present study was to focus on the growth promotion and wilt diseases protection of tomato plants by Bacillus sp. LBF-01.The plant growth promotion (both in vitro and in vivo) and diseases protection mechanism were studied following standard protocols. This bacterial strain showed positive PGP and antifungal traits against the wilt pathogen Fusarium sp. The seed bacterization with Bacillus sp. LBF-01 improved the germination rate of tomato seeds by 20% compared to the control whereas the vigor index was increased by 854.026%.The percentage of disease protection by Bacillus sp. LBF-01 against root-rot disease inoculated was inversely proportional to the doses of fungal spores inoculum. Under in vivo condition, the PGP bacteria enhanced the seedling growth in nursery as well as field condition. Application of Bacillus sp. LBF-01 enhanced the activity of defense related enzymes in root and leaves. Bacillus sp. LBF-01 treatment had significantly enhanced total chlorophyll and carotenoids contents of leaves by 77.78 and 52.5% over untreated control plants. It is evident from the present study that the application of the Bacillus sp. LBF-01 bacterial strain in tomato soil improved the potentiality of the plant by systemic resistance and control the wilt diseases for tomato production.