Soybean CHX-type ion transport protein GmSALT3 confers leaf Na+ exclusion via a root derived mechanism, and Cl- exclusion via a shoot derived process
Soybean CHX-type ion transport protein GmSALT3 confers leaf Na+ exclusion via a root derived mechanism, and Cl- exclusion via a shoot derived process
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DOI：
10.1111/pce.13947
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发表时间：
2020-12-08
影响因子：
7.3
通讯作者：
Gilliham, Matthew
中科院分区：
文献类型：
--
作者：
Qu, Yue;Guan, Rongxia;Gilliham, Matthew
大豆（Glycine max）产量受到包括土壤盐分在内的多重胁迫的威胁。GmSALT 3（一种阳离子质子交换蛋白）可以排除Na+和Cl-的净芽，提高大豆的耐盐性;然而，ER定位的GmSALT 3如何实现这一点尚不清楚。在这里，GmSALT 3的功能进行了研究，在异源系统和近等基因系，含有全长GmSALT 3（NIL-T;耐盐）或截短的转录Gmsalt 3（NIL-S;盐敏感）。GmSALT 3恢复了K+吸收缺陷大肠杆菌的生长，并有助于非洲爪蟾卵母细胞中Na+、K+和Cl-的净流入和积累，而Gmsalt 3则无功能。近等离子体的时程分析证实，芽Cl-排斥发生明显的Na+排斥。嫁接表明，芽Na+排斥发生通过根木质部为基础的机制，相反，NIL-T植物表现出显着更大的Cl-含量在茎木质部和韧皮部汁液相比，NIL-S，表明芽Cl-排斥可能取决于新的韧皮部为基础的Cl-再循环。NIL-S根上嫁接的NIL-T芽含有低的芽Cl-，这证实Cl-再循环依赖于芽中GmSALT 3的存在。总的来说，这些发现提供了新的见解GmSALT 3的耐盐性的影响，并揭示了一种新的机制，在植物中的芽氯排斥。
Soybean (Glycine max) yields are threatened by multiple stresses including soil salinity. GmSALT3 (a cation-proton exchanger protein) confers net shoot exclusion for both Na+ and Cl- and improves salt tolerance of soybean; however, how the ER-localized GmSALT3 achieves this is unknown. Here, GmSALT3's function was investigated in heterologous systems and near isogenic lines that contained the full-length GmSALT3 (NIL-T; salt-tolerant) or a truncated transcript Gmsalt3 (NIL-S; salt-sensitive). GmSALT3 restored growth of K+-uptake-defective Escherichia coli and contributed towards net influx and accumulation of Na+, K+ and Cl- in Xenopus laevis oocytes, while Gmsalt3 was non-functional. Time-course analysis of NILs confirmed shoot Cl- exclusion occurs distinctly from Na+ exclusion. Grafting showed that shoot Na+ exclusion occurs via a root xylem-based mechanism; in contrast, NIL-T plants exhibited significantly greater Cl- content in both the stem xylem and phloem sap compared to NIL-S, indicating that shoot Cl- exclusion likely depends upon novel phloem-based Cl- recirculation. NIL-T shoots grafted on NIL-S roots contained low shoot Cl-, which confirmed that Cl- recirculation is dependent on the presence of GmSALT3 in shoots. Overall, these findings provide new insights on GmSALT3's impact on salinity tolerance and reveal a novel mechanism for shoot Cl- exclusion in plants.