Department of Agronomy and Horticulture, University of Nebraska Lincoln, Lincoln, NE, 68588, USA.
Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN, 55108.
Environ Microbiol. 2020 Mar;22(3):889-904. doi: 10.1111/1462-2920.14701. Epub 2019 Jun 26.
Root-associated microbial communities are important for maintaining agricultural productivity. However, belowground microbial community response to drought in temperate maize agroecosystems, as well as how these responses to water-stress are shaped by host genotype are poorly understood. Ten maize hybrids (six newer and four older) were grown in a replicated field trial. The endosphere, rhizosphere and soil bacterial and archaeal communities were sampled and analyzed using 16S rRNA gene amplicon sequencing. Sampling was done at two developmental stages in a water-limited environment with and without supplemental irrigation. Significant shifts in microbial community composition (β-diversity) were measured between two sampling times during the season, in well-watered and water-stressed conditions and in newer and older generation maize hybrids. The microbial community diversity within samples (α-diversity) was not affected by drought stress or host factors. The phyla Actinobacteria and Firmicutes were more abundant in the rhizosphere of newer hybrids under water stress. These results highlight the importance of temporal variation, environmental stress and plant genetics as influenced by breeding history in shaping the composition of root associated microbial communities. These insights may provide new approaches to the improvement of crop stress tolerance through optimizing microbial communities.
根相关微生物群落对于维持农业生产力至关重要。然而，在温带玉米农业生态系统中，地下微生物群落对干旱的响应，以及这些对水分胁迫的响应如何受到宿主基因型的影响，还知之甚少。十个玉米杂交种（六个较新的和四个较旧的）在重复的田间试验中种植。使用 16S rRNA 基因扩增子测序对内生菌、根际和土壤细菌和古菌群落进行了采样和分析。在限水和非限水环境中，在有和没有补充灌溉的情况下，在两个发育阶段进行了采样。在季节中两个采样时间之间，在水分充足和水分胁迫条件下，以及在较新和较旧一代玉米杂交种之间，测量了微生物群落组成（β多样性）的显著变化。干旱胁迫或宿主因素并未影响样品内的微生物群落多样性（α多样性）。在水分胁迫下，新型杂交种的根际中放线菌和厚壁菌门更为丰富。这些结果强调了时间变化、环境胁迫和植物遗传因素作为由育种历史影响塑造与根相关的微生物群落组成的重要性。这些见解可能为通过优化微生物群落来提高作物的抗胁迫能力提供新方法。
