The anion channel SLAH3 interacts with potassium channels to regulate nitrogen–potassium homeostasis and the membrane potential in Arabidopsis

作者：Beibei Liu, Changxin Feng, Xianming Fang, Zhen Ma, Chengbin Xiao, Shuaishuai Zhang, Zhenzhen Liu, Doudou Sun, Hongyong Shi, Xiaoqin Ding, Chenyang Qiu, Jia Li, Sheng Luan, Legong Li, Kai He · 发表于：The Plant Cell · 年份：2023 · DOI：10.1093/plcell/koad014 · 被引用次数：32 · 研究领域：Plant Stress Responses and Tolerance、Plant nutrient uptake and metabolism、Aluminum toxicity and tolerance in plants and animals

Nitrogen (N) and potassium (K) are essential macronutrients for plants. Sufficient N and K uptake from the environment is required for successful growth and development. However, how N and K influence each other at the molecular level in plants is largely unknown. In this study, we found loss-of-function mutation in SLAH3 (SLAC1 HOMOLOGUE 3), encoding a NO3- efflux channel in Arabidopsis thaliana, enhanced tolerance to high KNO3 concentrations. Surprisingly, slah3 mutants were less sensitive to high K+ but not NO3-. Addition of NO3- led to reduced phenotypic difference between wild-type and slah3 plants, suggesting SLAH3 orchestrates NO3--K+ balance. Non-invasive Micro-test Technology analysis revealed reduced NO3- efflux and enhanced K+ efflux in slah3 mutants, demonstrating that SLAH3-mediated NO3- transport and SLAH3-affected K+ flux are critical in response to high K +. Further investigation showed that two K+ efflux channels, GORK (GATED OUTWARDLY-RECTIFYING K+ CHANNEL) and SKOR (STELAR K+ OUTWARD RECTIFIER), interacted with SLAH3 and played key roles in high K+ response. The gork and skor mutants were slightly more sensitive to high K+ conditions. Less depolarization occurred in slah3 mutants and enhanced depolarization was observed in gork and skor mutants upon K+ treatment, suggesting NO3-/K+ efflux-mediated membrane potential regulation is involved in high K+ response. Electrophysiological results showed that SLAH3 partially inhibited the activities of GORK and SKOR ...