The aquaporin MePIP2;7 improves MeMGT9-mediated Mg2+ acquisition in cassava

作     者：Qiuxiang Ma Yancai Feng Shu Luo Lu Cheng Weijing Tong Xinlu Lu Youzhi Li Peng Zhang Qiuxiang Ma;Yancai Feng;Shu Luo;Lu Cheng;Weijing Tong;Xinlu Lu;Youzhi Li;Peng Zhang

作者机构：National Key Laboratory of Plant Molecular GeneticsCAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032China College of Life SciencesUniversity of Chinese Academy of SciencesBeijing 100049China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/College of Life Science and TechnologyGuangxi UniversityNanning 530004China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2023年第65卷第10期

页      面：2349-2367页

核心收录：

学科分类：09[农学] 0901[农学-作物学] 

基　　金：supported by grants from the National Natural Science Foundation of China (31801417) Natural Science Foundation of Shanghai (17ZR1435200) the Open Project of State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources (SKLCUSA-b201703) the Earmarked Fund for China Agriculture Research System (CARS-11) 

主　　题：aquaporin cassava magnesium transporter nutrient utilization protein interaction 

摘      要：Aquaporins are important transmembrane water transport proteins which transport water and several neutral molecules. However, how aquaporins are involved in the synergistic transport of Mg2+and water remains poorly understood. Here, we found that the cassava aquaporin Me PIP2;7 was involved in Mg2+transport through interaction with Me MGT9, a lower affinity magnesium transporter protein. Knockdown of Me PIP2;7 in cassava led to magnesium deficiency in basal mature leaves with chlorosis and necrotic spots on their edges and starch over-accumulation. Mg2+content was significantly decreased in leaves and roots of Me PIP2;7-RNA interference(PIP-Ri) plants grown in both field and Mg2+-free hydroponic solution. Xenopus oocyte injection analysis verified that Me PIP2;7 possessed the ability to transport water only and Me MGT9 was responsible for Mg^(2+)*** importantly, Me PIP2;7 improved the transportability of Mg^(2+)via Me MGT9 as verified using the CM66 mutant complementation assay and Xenopus oocytes expressing system. Yeast twohybrid, bimolecular fuorescence complementation,co-localization, and co-immunoprecipitation assays demonstrated the direct protein–protein interaction between Me PIP2;7 and Me MGT9 in vivo. Mg2+fux was significantly elevated in Me PIP2;7-overexpressing lines in hydroponic solution through non-invasive micro-test technique analysis. Under Mg^(2+)-free condition, the retarded growth of PIP-Ri transgenic plants could be recovered with Mg^(2+)supplementation. Taken together, our results demonstrated the synergistic effect of the Me PIP2;7 and Me MGT9 interaction in regulating water and Mg2+absorption and transport in cassava.