Endophytic Micrococcus sp. TCR-5 ameliorates drought stress in rice plants and improves soil enzymatic activity
摘要
Environmental stressors, such as prolonged drought episodes, have significantly impacted rice productivity, posing a threat to food security. However, plant-associated microbiota trigger multipronged metabolic modulations to enhance plant growth and resilience in response to drought conditions. Therefore, this study aimed to harness the capability of selected endophytic bacteria, either individually or in consortia, to alleviate the negative impact of drought stress on rice plants and to analyze the genome sequence of selected drought-tolerant strain.
ResultAmong the selected endophytes, Micrococcus sp. TCR-5 significantly enhanced the drought tolerance ability of rice plants by minimizing oxidative damage, as evidenced by decreased lipid peroxidation, H2O2 content, and PAL activity. In contrast, a significant enhancement in proline content, APX, CAT, POD, PPO, and SOD enzyme activities was observed under drought regimes. Moreover, under drought conditions, TCR-5 treatment resulted in a significant increase in soil ACP and DHA activity. The genome sequence analysis of Micrococcus sp. TCR-5 revealed a genome size of ~ 2.38 Mb with 73.3% GC content. In the TCR-5 genome, 925 genes related to plant growth promotion, along with 39 secondary metabolite biosynthetic gene clusters and 130 different CAZymes were identified. The strain also contains genes related to plant colonization and the neutralization of environmental stressors.
ConclusionOverall, the study shows that the root endophyte Micrococcus sp. TCR-5 is a promising plant growth-promoting drought-tolerant microbe that can be further utilized for field applications. Furthermore, an in-depth investigation into the TCR-5-plant-soil tripartite interaction will facilitate the broad application of this strain in the agricultural sector.