Tonoplast-associated calcium signaling regulates manganese homeostasis in Arabidopsis  

作　　者：Zhenqian Zhang Dali Fu Zhihui Sun Chuanfeng Ju Cuicui Miao Zhangqing Wang Dixiang Xie Liang Ma Zhizhong Gong Cun Wang 

机构地区：[1]State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences,Northwest A&F University,Yangling,Shaanxi 712100,People’s Republic of China [2]State Key Laboratory of Plant Physiology and Biochemistry,College of Biological Sciences,China Agricultural University,Beijing 100193,China [3]College of Life Sciences,Hebei University,Baoding,China

出　　处：《Molecular Plant》2021年第5期805-819,共15页分子植物（英文版）

基　　金：funded by grants from the National Natural Science Foundation of China(31770289 to C.W.);Northwest A&F University(Z111021604 to C.W.);the China Postdoctoral Science Foundation(Z109021802 to Z.Z.);partially supported by the open funds of the State Key Laboratory of Plant Physiology and Biochemistry'(SKLPPBKF1901 to Z.Z.).

摘　　要：Manganese(Mn)is an essential micronutrient in plants.However,excessive Mn absorption in acidic and waterlogged soils can lead to Mn toxicity.Despite their essential roles in Mn homeostasis,transcriptional and post-transcriptional modifications of Mn transporters remain poorly understood.Here,we demonstrated that high-Mn stress induces an obvious Ca^(2+) signature in Arabidopsis.We identified four calcium-dependent protein kinases,CPK4/5/6/11,that interact with the tonoplast-localized Mn and iron(Fe)transporter MTP8 in vitro and in vivo.The cpk4/5/6/11 quadruple mutant displayed a dramatic high-Mn-sensitive phenotype similar to that of the mtp8 mutant.CPKs phosphorylated the N-terminal domain of MTP8 primarily at the Ser31 and Ser32 residues.Transport assays combined with multiple physiological experiments on phospho-dead variant MTP8^(S31/32A)and phospho-mimetic variant MTP8^(S31/32D)plants under different Mn and Fe conditions suggested that Ser31 and Ser32 are crucial for MTP8 function.In addition,genetic analysis showed that CPKs functioned upstream of MTP8.In summary,we identified a tonoplast-associated calcium signaling cascade that orchestrates Mn homeostasis and links Mn toxicity,Ca^(2+) signaling,and Mn transporters.These findings provide new insight into Mn homeostasis mechanisms and Ca^(2+) signaling pathways in plants,providing potential targets for engineering heavy metal toxicity-tolerant plants.

关 键 词：MANGANESE CALCIUM calcium-dependent protein kinases MTP8 iron 

分 类 号：Q94[生物学—植物学]