Gouli Sandeep, Majeed Aqsa, Liu Jinbao, Moseley David, Mukhtar M Shahid, Ham Jong Hyun
Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
Department of Biology, University of Alabama at Birmingham, 3100 Science & Engineering Complex-East Science Hall, 902 14 Street South, Birmingham, AL 35294, USA.
Microorganisms. 2024 Dec 19;12(12):2630. doi: 10.3390/microorganisms12122630.
Drought stress has a significant impact on agricultural productivity, affecting key crops such as soybeans, the second most widely cultivated crop in the United States. Endophytic and rhizospheric microbial diversity analyses were conducted with soybean plants cultivated during the 2023 growing season amid extreme weather conditions of prolonged high temperatures and drought in Louisiana. Specifically, surviving and non-surviving soybean plants were collected from two plots of a Louisiana soybean field severely damaged by extreme heat and drought conditions in 2023. Although no significant difference was observed between surviving and non-surviving plants in microbial diversity of the rhizosphere, obvious differences were found in the structure of the endophytic microbial community in root tissues between the two plant conditions. In particular, the bacterial genera belonging to Proteobacteria, and , were predominant in the surviving root tissues, while the bacterial genus was conspicuously dominant in the non-surviving (dead) root tissues. Co-occurrence patterns and network centrality analyses enabled us to discern the intricate characteristics of operational taxonomic units (OTUs) within endophytic and rhizospheric networks. Additionally, we isolated and identified bacterial strains that enhanced soybean tolerance to drought stresses, which were sourced from soybean plants under a drought field condition. The 16S rDNA sequence analysis revealed that the beneficial bacterial strains belong to the genera , , , and . Specific bacterial strains, particularly those identified as and sp., significantly enhanced plant growth metrics and reduced drought stress indices in soybean plants through seed treatment. Overall, this study advances our understanding of the soybean-associated microbiome structure under drought stress, paving the way for future research to develop innovative strategies and biological tools for enhancing soybean resilience to drought.
干旱胁迫对农业生产力有重大影响，影响着诸如大豆等关键作物，大豆是美国种植面积第二广泛的作物。在路易斯安那州2023年生长季节高温持续和干旱的极端天气条件下，对种植的大豆植株进行了内生和根际微生物多样性分析。具体而言，从路易斯安那州一个大豆田的两块地中收集了存活和未存活的大豆植株，该大豆田在2023年受到极端高温和干旱条件的严重破坏。虽然在根际微生物多样性方面，存活植株和未存活植株之间未观察到显著差异，但在两种植株状况下，根组织内生微生物群落结构存在明显差异。特别是，属于变形菌门的细菌属在存活根组织中占主导地位，而在未存活（死亡）根组织中，细菌属显著占优。共现模式和网络中心性分析使我们能够识别内生和根际网络内操作分类单元（OTU）的复杂特征。此外，我们分离并鉴定了增强大豆对干旱胁迫耐受性的细菌菌株，这些菌株来自干旱田间条件下的大豆植株。16S rDNA序列分析表明，有益细菌菌株属于、、和属。特定的细菌菌株，特别是那些被鉴定为和sp.的菌株，通过种子处理显著提高了大豆植株的生长指标并降低了干旱胁迫指数。总体而言，本研究增进了我们对干旱胁迫下大豆相关微生物组结构的理解，为未来开发增强大豆抗旱复原力的创新策略和生物工具的研究铺平了道路。
