Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland, College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, 434025, China.
Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland, College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, 434025, China.
Plant Physiol Biochem. 2021 May;162:27-35. doi: 10.1016/j.plaphy.2021.02.026. Epub 2021 Feb 25.
Aquaporins (AQPs) involved in water and small molecule transport respond to environmental stress, while it is not clear how arbuscular mycorrhizal fungi (AMF) regulate AQP expression. Here, we investigated the change in leaf water potential and expression level of four tonoplast intrinsic proteins (TIPs), six plasma membrane intrinsic proteins (PIPs), and four nodin-26 like intrinsic proteins (NIPs) genes in trifoliate orange (Poncirus trifoliata) inoculated with Funneliformis mosseae under well-watered (WW), salt stress (SS), and waterlogging stress (WS). Root AMF colonization and soil hyphal length collectively were reduced by SS and WS. Under WW, inoculation with AMF gave diverse responses of AQPs: six AQPs up-regulated, three AQPs down-regulated, and five AQPs did not change. Such up-regulation of more AQPs under mycorrhization and WW partly accelerated water absorption, thereby, maintaining higher leaf water potential. However, under SS, all the fourteen AQPs were dramatically induced by AMF inoculation, which improved water permeability of membranes and stimulated water transport of the host. Under WS, AMF colonization almost did not induce or even down-regulated these AQPs expressions with three exceptions (PtTIP2;2, PtPIP1;1, and PtNIP1;2), thus, no change in leaf water potential. As a result, mycorrhizal plants under flooding may have an escape mechanism to reduce water absorption. It is concluded that AMF had different strategies in response to environmental stresses (e.g. SS and WS) by regulating leaf AQP expression in the host (e.g. trifoliate orange).
水通道蛋白（AQPs）参与水和小分子的转运，对环境胁迫做出响应，而丛枝菌根真菌（AMF）如何调节 AQP 的表达尚不清楚。在这里，我们研究了在水分充足（WW）、盐胁迫（SS）和淹水胁迫（WS）条件下，接种摩西管柄囊霉（Funneliformis mosseae）后，三叶枳（Poncirus trifoliata）叶片水势的变化和 4 种液泡膜内在蛋白（TIPs）、6 种质膜内在蛋白（PIPs）和 4 种 nodin-26 内在蛋白（NIPs）基因的表达水平。SS 和 WS 导致根 AMF 定殖和土壤菌丝长度减少。在 WW 条件下，接种 AMF 对 AQPs 有不同的反应：6 个 AQP 上调，3 个 AQP 下调，5 个 AQP 没有变化。在共生和 WW 条件下，更多 AQP 的上调部分加速了水分的吸收，从而维持了较高的叶片水势。然而，在 SS 条件下，所有 14 个 AQPs 都被 AMF 接种强烈诱导，这提高了膜的透水性并刺激了宿主的水分运输。在 WS 条件下，AMF 定殖几乎没有诱导或甚至下调这些 AQP 的表达，只有 3 个例外（PtTIP2;2、PtPIP1;1 和 PtNIP1;2），因此叶片水势没有变化。结果，水淹条件下的菌根植物可能有一种逃避机制来减少水分吸收。结论是，AMF 通过调节宿主（如三叶枳）叶片 AQP 的表达，对环境胁迫（如 SS 和 WS）有不同的策略。
