Diversity analysis of antagonistic microbes against bacterial leaf and fungal sheath blight diseases of rice

Abstract

Background Biocontrol is an effective strategy in the integrated management of plant diseases, now more as a necessity than choice, in the present era of environmental and health awareness. Microbial diversity is a wonder by nature that inspires to explore and accordingly, the diversity analysis of the isolated microbes revealed their morphological and molecular differences. The DNA provides a common platform to store the microbial information in the form of databases in public domain that can be used by anyone from anywhere. Results Exploration for native microbes in the present study resulted in isolation of different isolates of Trichoderma and Bacillus. The microbes were identified using morphological traits and molecular markers and the key conserved 18S and 16S gene sequences submitted with the appropriate repositories. Nucleotide analysis indicated a close phylogenetic relationship between BIK 2 and BIK 3 (Bacillus isolates) and within all the 5 Trichoderma isolates. The percent disease reduction of Rhizoctonia solani and Xanthomonas oryzae pv. oryzae (Xoo) was more in plants treated with consortia of the Trichoderma (61.13%) and Bacillus (53.59%) isolates, respectively. Screening of plant growth promotion activities, percentage increase in root (41.00%) and shoot length (44.77%) were found to be maximum in Trichoderma consortia treated plants. Conclusions Three Bacillus and one Trichoderma strains, viz., B. velezensis, B. subtilis and B. paralicheniformis and Trichoderma asperellum, were identified and found to be effective against R. solani and Xoo pathogens of rice. In vitro and in vivo studies indicated that TAIK1 and BIK3 were found to be the most potential isolates among others isolated. Ability to improve plant growth was more pronounced by consortia of microbes.

Native bioagents released phytohormones induce biochemical changes in rice against stem rot and false smut diseases

“…They also produce plant growth-promoting hormones and other alkaloids like siderophores which improves availability of Fe to the plants (Stuti et al, 2021). The other bioagents viz., TAIK1 and BIK3 were found to improve all plant growth parameters in rice as reported earlier (Kannan et al, 2021). Trichoderma help plants to acquire nutrients such as phosphorus, nitrogen, and other micronutrients by secreting enzymes that break down organic matter in the soil and converts complex matter to simpler substances (Yedidia, et al, 2000).…”

Performance of Novel Antimicrobial Protein Bg_9562 and In Silico Predictions on Its Properties with Reference to Its Antimicrobial Efficiency against Rhizoctonia solani

“…Significant bioactivity of the protein at higher temperatures (45 • C) indicates the thermostability of the protein to withstand application in the late sown crop in tropical conditions, where the temperature ranges above 35 • C during most stages of the crop cycle [31]. Positive compatibility studies of Bg_9562 with native antagonistic/plant growth promoting fungi and bacteria isolated and characterized at this institute, viz., TAIK and BIK3 strains [18], would help in co-application of Bg_9562 along with the biocontrol agents for the management of ShB disease in rice. In addition to their plant protection properties, plant growth promotion by Bacillus and Trichoderma species will give an additional benefit to the plants.…”

“…The physicochemical properties, transmembrane regions, and thermal stability-related residues of the protein were determined in silico and correlated with wet-lab experiments and bioactivity assays of Bg_9562 on RS. The interaction of Bg_9562 with potential native biocontrol agents Trichoderma asperellum TAIK1 and Bacillus subtilis BIK3 [18] was studied, which helps in the use of this protein along with the biocontrol agents. In summary, this study aims to identify the antimicrobial properties of Bg_9562 for its effective usage as a biocontrol agent to fight against sheath blight disease of rice.…”

Whole genome sequencing data of native isolates of Bacillus and Trichoderma having potential biocontrol and plant growth promotion activities in rice

“… The table is modified from Tables 1 and 2 from the article referred - 10.1186/s41938-021-00462-x [1] . …”

“…For instance, TAIK1 application on 30 th day of transplantation released growth promoting substances and also suppress the infection induced by R. solani and S. oryzae. It has also been reported that the bioagents application needs to be standardised for different varieties [1] .…”