Golgi‐localized cation/proton exchangers regulate ionic homeostasis and skotomorphogenesis in Arabidopsis

• DOI: 10.1111/pce.13452
• Publication Date: 2018-09-26T00:39:34Z
• Authors: Yuan Wang; Ren‐Jie Tang; Xiyan Yang; Xiaojiang Zheng; Qiaolin Shao; Qing‐Lin Tang; Aigen Fu; Sheng Luan
• Keywords: Homeostasis; Proton Transport; Etiolation

Multiple transporters and channels mediate cation transport across the plasma membrane tonoplast to regulate ionic homeostasis in plant cells. However, much less is known about molecular function of that facilitate other organelles such as Golgi. We report here Arabidopsis KEA4, KEA5, KEA6, members cation/proton antiporters-2 (CPA2) superfamily were colocalized with Golgi marker, SYP32-mCherry. Although single kea4,5,6 mutants showed similar phenotype wild type under various conditions, kea4/5/6 triple hypersensitivity low pH, high K+ , Na+ displayed growth defects darkness, suggesting these three KEA-type redundantly controlling etiolated seedling ion homeostasis. Detailed analysis indicated mutant exhibited cell wall biosynthesis defect during rapid /Na+ condition. The wall-derived pectin homogalacturonan (GalA)3 partially suppressed toxicity when grown dark but not light conditions. Together, data support hypothesis Golgi-localized KEAs play key roles maintenance pH homeostasis, thereby facilitating coping stress.