Mechanisms of vacuolar phosphate efflux supporting soybean root hair growth in response to phosphate deficiency  

作　　者：Zhong Shan Yanli Chu Guangfang Sun Rui Chen Jun Yan Qiwei He Yingna Liu Bin Wang Mingda Luan Wenzhi Lan 

机构地区：[1]School of Life Sciences,Nanjing University,Nanjing 210023,China [2]Institute of Future Agriculture,Northwest A&F University,Yangling 712100,China

出　　处：《Journal of Integrative Plant Biology》2024年第9期1983-1999,共17页植物学报（英文版）

基　　金：Supported by National Natural Science Foundation of China 32200216(to M.L.);National Natural Science Foundation of China 32370279(to M.L.);Northwest A&F University Start‐up Funding(to M.L.and W.L.).

摘　　要：Phosphorus is an essential macronutrient for plant growth and development.In response to phosphate(Pi)deficiency,plants rapidly produce a substitutive amount of root hairs;however,the mechanisms underlying Pi supply for root hair growth remain unclear.Here,we observed that soybean(Glycine max)plants maintain a consistent level of Pi within root hairs even under external Pi deficiency.We therefore investigated the role of vacuole-stored Pi,a major Pi reservoir in plant cells,in supporting root hair growth under Pi-deficient conditions.Our findings indicated that two vacuolar Pi efflux(VPE)transporters,GmVPE1 and GmVPE2,remobilize vacuolar stored Pi to sustain cytosolic Pi content in root hair cells.Genetic analysis showed that double mutants of GmVPE1 and GmVPE2 exhibited reduced root hair growth under low Pi conditions.Moreover,GmVPE1 and GmVPE2 were highly expressed in root hairs,with their expression levels significantly upregulated by low Pi treatment.Further analysis revealed that GmRSL2(ROOT HAIR DEFECTIVE 6-like 2),a transcription factor involved in root hair morphogenesis,directly binds to the promoter regions of GmVPE1 and GmVPE2,and promotes their expressions under low Pi conditions.Additionally,mutants lacking both GmRSL2 and its homolog GmRSL3 exhibited impaired root hair growth under low Pi stress,which was rescued by overexpressing either GmVPE1 or GmVPE2.Taken together,our study has identified a module comprising vacuolar Pi exporters and transcription factors responsible for remobilizing vacuolar Pi to support root hair growth in response to Pi deficiency in soybean.

关 键 词：mineral deficiency REMOBILIZATION root remodeling transcriptional regulation 

分 类 号：S565.1[农业科学—作物学]