CHLORIDE CHANNEL-b mediates vacuolar nitrate efflux to improve low nitrogen adaptation in Arabidopsis

被引：5

作者：

Shi, Yujiao ^{[1
]}

Liu, Dong ^{[1
]}

He, Yiqi ^{[1
]}

Tang, Jing ^{[1
]}

Chen, Haifei ^{[1
,2
]}

Gong, Pan ^{[1
,2
]}

Luo, Jin-Song ^{[1
,2
]}

Zhang, Zhenhua ^{[1
,2
]}

机构：

[1] Hunan Agr Univ, Coll Resources, Changsha 410128, Peoples R China

[2] Natl Engn Lab Soil & Fertilizer Resources Efficien, Hunan Prov Key Lab Nutr Common Univ, Hunan Prov Key Lab Farmland Pollut Control & Agr R, Changsha 410128, Peoples R China

来源：

PLANT PHYSIOLOGY | 2023年 / 193卷 / 03期

基金：

中国国家自然科学基金;

关键词：

LEAF SENESCENCE; SUBCELLULAR-LOCALIZATION; TRANSCRIPTION; TRANSPORT; REALLOCATION; STARVATION; TONOPLAST; MUTANTS; CADMIUM; NRT1.5;

D O I：

10.1093/plphys/kiad438

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

CHLORIDE CHANNEL-b functions as a vacuolar nitrate efflux transporter and is negatively regulated by HRS1 HOMOLOG2, providing a theoretical basis for improving plant adaptability to low nitrogen. The vacuole is an important organelle for nitrate storage, and the reuse of vacuolar nitrate under nitrate starvation helps plants adapt to low-nitrate environments. CHLORIDE CHANNEL-b (CLC-b) in the vacuolar membrane is a nitrate transporter; however, its regulation and effects on nitrate efflux have not been established. Here, we evaluated CLC-b expression and its effects on physiological parameters under low nitrate conditions. CLC-b expression increased significantly in the roots of wild-type Arabidopsis (Arabidopsis thaliana) Col-0 under nitrate starvation. Under low nitrate, clcb mutants showed reductions in chlorophyll content and xylem sap nitrate concentration, shoot/root nitrate ratios, shoot/root total N ratios, and biomass. CLC-b-overexpression yielded opposite phenotypes and increased nitrogen use efficiency. CLC-b mutants showed elevated chlorate tolerance and an increased proportion of vacuolar nitrate relative to the total protoplast nitrate content as compared to the wild type. Yeast 1-hybrid, EMSA, and chromatin immunoprecipitation (ChIP) experiments showed that HRS1 HOMOLOG2 (HHO2), the expression of which is downregulated under low nitrate, binds directly to the promoter of CLC-b. clcb/hho2 double mutants and HHO2-overexpressing clcb plants had similar phenotypes under low nitrate to those of clcb single mutants. Thus, CLC-b mediates vacuolar nitrate efflux and is negatively regulated by HHO2, providing a theoretical basis for improving plant adaptability to low nitrate.

引用

页码：1987 / 2002

页数：16