Perception of Biocontrol Potential of Bacillusinaquosorum KR2-7 against Tomato Fusarium Wilt through Merging Genome Mining with Chemical Analysis

Tomato Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici (Fol), is a destructive disease that threatens the agricultural production of tomatoes. In the present study, the biocontrol potential of strain KR2-7 against Fol was investigated through integrated genome mining and chemical analysis. Strain KR2-7 was identified as B. inaquosorum based on phylogenetic analysis. Through the genome mining of strain KR2-7, we identified nine antifungal and antibacterial compound biosynthetic gene clusters (BGCs) including fengycin, surfactin and Bacillomycin F, bacillaene, macrolactin, sporulation killing factor (skf), subtilosin A, bacilysin, and bacillibactin. The corresponding compounds were confirmed through MALDI-TOF-MS chemical analysis. The gene/gene clusters involved in plant colonization, plant growth promotion, and induced systemic resistance were also identified in the KR2-7 genome, and their related secondary metabolites were detected. In light of these results, the biocontrol potential of strain KR2-7 against tomato Fusarium wilt was identified. This study highlights the potential to use strain KR2-7 as a plant-growth promotion agent.

Genomic analysis and plant growth-promoting potential of a Serratia marcescens isolated from food

A genomic analysis of the potential application of a Serratia marcescens strain in the plant-growth promotion. We performed whole-genome sequencing of Serratia marcescens isolated from a Minas Frescal Cheese. The genomic repertoire revealed a bacterium of agricultural and biotechnological interest. In the plant-growth promotion traits, we highlight genes encoding proteins possibly responsible for the biosynthesis of phytohormone indole acetic acid, organic compounds that act in iron uptake, and the Phosphate solubilization system. Genes encoding for enzymes like the versatile L-asparaginase stimulates the development of seeds and grains and can benefit the food industry due to a mitigation effect on acrylamide and notably, has medical applications as a chemotherapeutic agent or is applicable by its antimicrobial and anti-inflammatory properties. Moreover, functional diversity of genes encoding for resistance to different metals and metabolism of xenobiotics genes can be found in this strain, reinforcing its biotechnological potential. The versatile enzymes that can be produced by S. marcescens benefit the food, pharmaceutical, textile, agronomic, and cosmetic industries. The relevant genetic systems of S. marcescens described here may be used to promote plant growth and health and improve the environment. To the best of our knowledge, this is the first genome sequence report on S. marcescens isolated from cheese, with potential application as promoting plant growth and providing a baseline for future genomic studies on the development of this species.

Seed treatment using rhizobacteria as plant growth promotion of two chili variety (Capsicum annuum L.)

The research aims to find out the effect of pre-germination treatment seeds using rhizobacteria as plant growth promotion of two varieties of red chili peppers in the field. The experiment used a randomized design of factorial groups. Factors studied were varieties (V) and rhizobacteria types (R). The variety factor consists of 2 varieties namely PM999 (V1) and Kiyo F1 (V2). While the type of rhizobacteria factor tried consists of 8 treatment, namely, control (R0), Azotobacter sp. (R1), B. megaterium (R2), P. atmuta (R3), B. alvei (R4), Flavobacterium sp. (R5), B. coagulans (R6), B. firmus (R7) and B. pilymixa (Rs). Each treatment was repeated 3 times, so there were 48 experimental units. Each unit of experiment is represented by 5 sample plants. The data was analyzed using ANOVA and continued with DMRT test at real level α = 0.05. The results showed that vegetative growth and production of chili plants until the age of 45 days after planting in each variety is not dependent on the pre-germination treatment of seeds with rhizobacteria. But the varieties of chili plants used affect vegetative growth and production. PM999 varieties are superior to the Kiyo F1 variety. Pre-germination treatment of seeds using rhizobacteria is relatively effective in improving vegetative growth and yield of chili plants. Among the 8 isolates rizobacteria isolate Azotobacter sp., B. megaterium, B. coagulants, Flavobacterium sp., and P. atmuta relatively effective to provide an increased effect on the growth and production of chili plants.

Plant Based Biosynthesis of Copper Nanoparticles and its Efficacy on Seed Viability and Seedling Growth in Peanut (Arachis hypogaea Linn.)

Nano-fertilizers can easily adsorb into the plant and can increase the reactive points in the plant and hence are treated as an efficient alternative to the conventional fertilizers. Based on this, the present study was intended to synthesize copper nanoparticles (CuNPs) using aqueous root extract of Schrebera swietenioides Roxb. as green reducing agent. The synthesized nanoparticles were studied for its effectiveness on enhancement of seed germination and plant growth promotion on peanut (Arachis hypogaea Linn.). The formation of nanoparticles was confirmed by observing colour change in the reaction mixture, which shows characteristic absorption maxima at 340 nm. The SEM and TEM analysis confirmed that the nanoparticles were in monodispersed with spherical to irregular shape with an average particle size of 35 nm. The EDX analysis confirmed that the nanoparticles contain 82.5% copper metal. The synthesized nanoparticles were applied for its seed germination enhancement activity on peanut seeds and results confirms that the nanoparticles were significantly enhances the germination of peanut seeds with decrease in mean germination time. The peanut plant growth also enhances when compared with metal solution treatment and untreated plants. The root length of CuNPs treated plants was observed to be 9.27 ± 0.15 cm, which is significantly more than the untreated (6.40 ± 0.10 cm) as well as treated copper metal (7.13 ± 0.25 cm) plants. The shoot length of 19.13 ± 0.20 cm was observed for nano-treated plants and is greatly enhanced than the untreated (10.30 ± 0.20 cm) and treated copper metal (11.27 ± 0.25 cm) plants. The protease activity on day 5 of the germination study was found to be 0.904 ± 0.004, 0.133 ± 0.002 and 0.095 ± 0.002 units/mL, respectively for the peanut seeds treated with CuNPs, copper metal solution and untreated conditions. The catalase activity at 5th day of seed germination studies the activity was observed to be 45.177 ± 0.192, 23.691 ± 0.074 and 18.331 ± 0.209 units/min/g, respectively for CuNPs treated, copper sulphate treated and untreated pea nut seeds. The water update of the nano treated seeds was observed to be very high along with high quantity of photosynthetic pigments when compared with the other treatments in the study. Based on the results achieved, it can be confirmed that the nano-treatment enhances the seed germination and plant growth promotion on peanut seeds.

Metagenomic insights into plant growth promoting genes inherent in bacterial endophytes of Emilia sonchifolia (Linn.) DC

Studies on the genome of endophytes reveal the metabolic potential of endophytic microbiome including both culturable and unculturable fractions. The metagenome analysis through the Illumina HiSeq platform gives access to the genetic data encrypted for the molecular machinery, which takes part in plant growth promotion activity of the endophyte in various aspects including production of plant growth hormones and enhancing nutrient availability for the host plant. The present work was undertaken to identify the genes involved in plant growth promotion activities from the endophytes of Emilia sonchifolia(Linn.) DC. through metagenome analysis. Metagenomic studies include the analysis of functional annotations which aid in the detection of biocatalysts taking part in the metabolic pathway of host plants. The annotations of expressed genes in different databases like NCBI Nr, KEGG, eggnog and CAZy resulted in enlisting the vast array of information on the genetic diversity of the endophytic microbiome. The metagenome analysis of endophytic bacteria from the medicinal plant E.sonchifolia unveiled characteristic functional genes involved in plant growth promotion such as nitrogen metabolism (nif) and siderophore production (enterobactin category), ipdC and tnaA (IAA producing), ACC deaminase coding genes (regulation of elevated ethylene levels in host tissues), Mo-Nitrogenase, nitrous-oxide reductase (nosZ), nitrate reductase (narG, napA), nitrite reductase (nirD) (nutrient assimilation and absorption) enterobactin siderophore synthetase components F and D and acid phosphatase genes. This clearly explains the effective plant-microbe relationship and the role of bacterial endophytic microbes in regulating the growth of host plants.

IMPACT OF PESTICIDE TOLERANT SOIL BACTERIA ON DISEASE CONTROL, PLANT GROWTH PROMOTION AND SYSTEMIC RESISTANCE IN COWPEA

Cowpea, an annual legume, suffers from several disease symptoms caused by Macrophomina phaseolina. Rhizobacteria isolated from pesticide infested soil, identified by blast analysis as Bacillus cereus, Bacillus safensis, Pseudomonas donghuensis and Pseudomonas aeruginosa ascertained tolerant to at least 0.1% pesticides viz. methomyl, imidacloprid and carbendazim. In vitro antagonism against pathogen exhibited maximum by P. aeruginosa 63%. All rhizobacteria were bestowed with attributes responsible for pathogen control and plant growth promotion. Field evaluation resulted highest 75% disease control, enhancement of length, nodule counts, biomass or yield per plant by P. aeruginosa. All rhizobacteria induced systemic resistance in cowpea under challenged inoculation with pathogen by augmenting defensive enzyme production. Highest Phenylalanine Ammonia Lyase activity was expressed in P. aeruginosa treated plants 1.02 μMoles/ml/min, Polyphenol Oxidase by P. donghuensis 1.39 μMoles/ml/min, Chitinase by B. cereus 0.745 μMoles/ml/min and 400 percent relative activity of Peroxidase by P. aeruginosa. The rhizobacteria were prospective for plant disease control, growth promotion and as immunity boosters in pesticide and heavy metal infested toxic environment.