Liu Yuhan, Mao Jiao, Xu Yuanmeng, Ren Jiangling, Wang Mengyao, Wang Shu, Liu Sichen, Wang Ruiyun, Wang Lun, Wang Liwei, Qiao Zhijun, Cao Xiaoning
Center for Agricultural Genetic Resources Research, Shanxi Agricultural University, Taiyuan 030031, China.
College of Agriculture, Shanxi Agricultural University, Jinzhong 030801, China.
Microorganisms. 2024 Jul 26;12(8):1534. doi: 10.3390/microorganisms12081534.
This study aimed to elucidate responses of the bacterial structure and diversity of the rhizosphere in flowering broomcorn millet after rehydration following drought stress. In this study, the broomcorn millet varieties 'Hequ red millet' (A1) and 'Yanshu No.10' (A2), known for their different drought tolerance levels, were selected as experimental materials. The plants were subjected to rehydration after drought stress at the flowering stage, while normal watering (A1CK and A2CK) served as the control. Soil samples were collected at 10 days (A11, A21, A1CK1, and A2CK1) and 20 days (A12, A22, A1CK2, and A2CK2) after rehydration. High-throughput sequencing technology was employed to investigate the variations in bacterial community structure, diversity, and metabolic functions in the rhizosphere of the broomcorn millet at different time points following rehydration. The findings indicated that the operational taxonomic units (OTUs) of bacteria in the rhizosphere of broomcorn millet were notably influenced by the duration of treatment, with a significant decrease in OTUs observed after 20 days of rehydration. However, bacterial Alpha diversity was not significantly impacted by rehydration following drought stress. The bacterial community in the rhizosphere of broomcorn millet was mainly composed of and . After rewatering for 10 to 20 days after drought stress, the abundance of and in the rhizosphere soil of the two varieties of broomcorn millet decreased gradually. Compared with Yanshu No.10, the abundance of in the rhizosphere of Hequ red millet gradually increased. A Beta diversity analysis revealed variations in the dissimilarities of the bacterial community which corresponded to different rehydration durations. The relative abundance of bacterial metabolic functions in the rhizosphere of broomcorn millet was lower after 20 days of rehydration, compared to measurements after 10 days of rehydration. This observation might be attributed to the exchange of materials between broomcorn millet and microorganisms during the initial rehydration stage to repair the effects of drought, as well as to the enrichment of numerous microorganisms to sustain the stability of the community structure. This study helps to comprehend the alterations to the bacterial structure and diversity in the rhizosphere of broomcorn millet following drought stress and rehydration. It sheds light on the growth status of broomcorn millet and its rhizosphere microorganisms under real environmental influences, thereby enhancing research on the drought tolerance mechanisms of broomcorn millet.
本研究旨在阐明干旱胁迫后复水的开花期黍稷根际细菌结构和多样性的响应。在本研究中，选择了耐旱水平不同的黍稷品种‘河曲红谷’（A1）和‘延谷10号’（A2）作为实验材料。在开花期对植株进行干旱胁迫后复水，同时以正常浇水（A1CK和A2CK）作为对照。在复水后10天（A11、A21、A1CK1和A2CK1）和20天（A12、A22、A1CK2和A2CK2）采集土壤样本。采用高通量测序技术研究复水后不同时间点黍稷根际细菌群落结构、多样性和代谢功能的变化。研究结果表明，黍稷根际细菌的可操作分类单元（OTUs）受处理时间的显著影响，复水20天后OTUs显著减少。然而，干旱胁迫后的复水对细菌的α多样性没有显著影响。黍稷根际细菌群落主要由 和 组成。干旱胁迫后复水10至20天，两个黍稷品种根际土壤中 和 的丰度逐渐降低。与延谷10号相比，河曲红谷根际 的丰度逐渐增加。β多样性分析揭示了细菌群落差异的变化，这些变化与不同的复水持续时间相对应。与复水10天后的测量结果相比，复水20天后黍稷根际细菌代谢功能的相对丰度较低。这一观察结果可能归因于复水初期黍稷与微生物之间的物质交换以修复干旱的影响，以及大量微生物的富集以维持群落结构的稳定性。本研究有助于理解干旱胁迫和复水后黍稷根际细菌结构和多样性的变化。它揭示了在实际环境影响下黍稷及其根际微生物的生长状况，从而加强了对黍稷耐旱机制的研究。
