Zhang Zhihao, Chai Xutian, Zhang Bo, Lu Yan, Gao Yanju, Tariq Akash, Li Xiangyi, Zeng Fanjiang
Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China.
Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Plant Physiol Biochem. 2023 Nov;204:108124. doi: 10.1016/j.plaphy.2023.108124. Epub 2023 Oct 26.
Plants possess the ability to adapt to osmotic stress by adjusting their physiology and morphology and by cooperating with their root-associated (rhizosphere and endosphere) microbial communities. However, the coordination of host self-regulation with root-associated microorganisms at the community level, especially for desert plants, remains unclear. This study investigated the morphophysiological responses of seedlings from the desert plant Alhagi sparsifolia Shap to osmotic stress, as well as the relationships between these adaptations and their root-associated bacterial communities. The results indicated that osmotic stress contributed to a reduction in height and increased levels of reactive oxygen species (ROS) and malondialdehyde (MDA). In response, A. sparsifolia exhibited a series of morphophysiological adjustments, including increased ratio of root to shoot biomass (R/S) and the number of root tip, enhanced vitality, high levels of peroxidase (POD), ascorbate peroxidase (APX), and glutathione (GSH), as well as osmolytes (proline, soluble protein, and soluble sugar) and modification in phytohormones (abscisic acid (ABA) and jasmonic acid (JA)). Additionally, osmotic stress resulted in alterations in the compositions and co-occurrence patterns of root-associated bacterial communities, but not α-diversity (Chao1). Specifically, the rhizosphere Actinobacteria phylum was significantly increased by osmotic stress. These shifts in root-associated bacterial communities were significantly correlated with the host's adaptation to osmotic stress. Overall, the findings revealed that osmotic stress, in addition to its impacts on plant physiology, resulted in a restructuring of root-associated microbial communities and suggested that the concomitant adjustment in plant microbiota may potentially contribute to the survival of desert plants under extreme environmental stress.
植物具有通过调节自身生理和形态以及与根系相关（根际和内生菌）微生物群落协作来适应渗透胁迫的能力。然而，宿主自我调节与根系相关微生物在群落水平上的协调，尤其是对于沙漠植物而言，仍不清楚。本研究调查了沙漠植物疏叶骆驼刺（Alhagi sparsifolia Shap）幼苗对渗透胁迫的形态生理响应，以及这些适应性与根系相关细菌群落之间的关系。结果表明，渗透胁迫导致株高降低，活性氧（ROS）和丙二醛（MDA）水平升高。作为响应，疏叶骆驼刺表现出一系列形态生理调节，包括根与地上部生物量比（R/S）和根尖数量增加、活力增强、过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）和谷胱甘肽（GSH）水平升高，以及渗透调节物质（脯氨酸、可溶性蛋白和可溶性糖）和植物激素（脱落酸（ABA）和茉莉酸（JA））的变化。此外，渗透胁迫导致根系相关细菌群落的组成和共现模式发生改变，但α多样性（Chao1）未变。具体而言，渗透胁迫使根际放线菌门显著增加。根系相关细菌群落的这些变化与宿主对渗透胁迫的适应性显著相关。总体而言，研究结果表明，渗透胁迫除了影响植物生理外，还导致根系相关微生物群落的重组，并表明植物微生物群的伴随调整可能有助于沙漠植物在极端环境胁迫下生存。
