AtKC1 and CIPK23 Synergistically Modulate AKT1-Mediated Low-Potassium Stress Responses in Arabidopsis.

Autor:	Wang XP; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Chen LM; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Liu WX; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Shen LK; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wang FL; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Zhou Y; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Zhang Z; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wu WH; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wang Y; State Key Laboratory of Plant Physiology and Biochemistry, National Plant Gene Research Centre (X.-P.W., L.-M.C., W.-X.L., L.-K.S., F.-L.W., W.-H.W., Y.W.), and State Key Laboratory of Agrobiotechnology (Y.Z., Z.Z.), College of Biological Sciences, China Agricultural University, Beijing 100193, China yiwang@cau.edu.cn.
Jazyk:	angličtina
Zdroj:	Plant physiology [Plant Physiol] 2016 Apr; Vol. 170 (4), pp. 2264-77. Date of Electronic Publication: 2016 Feb 01.
DOI:	10.1104/pp.15.01493
Abstrakt:	In Arabidopsis (Arabidopsis thaliana), the Shaker K(+) channel AKT1 conducts K(+) uptake in root cells, and its activity is regulated by CBL1/9-CIPK23 complexes as well as by the AtKC1 channel subunit. CIPK23 and AtKC1 are both involved in the AKT1-mediated low-K(+) (LK) response; however, the relationship between them remains unclear. In this study, we screened suppressors of low-K(+) sensitive [lks1 (cipk23)] and isolated the suppressor of lks1 (sls1) mutant, which suppressed the leaf chlorosis phenotype of lks1 under LK conditions. Map-based cloning revealed a point mutation in AtKC1 of sls1 that led to an amino acid substitution (G322D) in the S6 region of AtKC1. The G322D substitution generated a gain-of-function mutation, AtKC1(D), that enhanced K(+) uptake capacity and LK tolerance in Arabidopsis. Structural prediction suggested that glycine-322 is highly conserved in K(+) channels and may function as the gating hinge of plant Shaker K(+) channels. Electrophysiological analyses revealed that, compared with wild-type AtKC1, AtKC1(D) showed enhanced inhibition of AKT1 activity and strongly reduced K(+) leakage through AKT1 under LK conditions. In addition, phenotype analysis revealed distinct phenotypes of lks1 and atkc1 mutants in different LK assays, but the lks1 atkc1 double mutant always showed a LK-sensitive phenotype similar to that of akt1 This study revealed a link between CIPK-mediated activation and AtKC1-mediated modification in AKT1 regulation. CIPK23 and AtKC1 exhibit distinct effects; however, they act synergistically and balance K(+) uptake/leakage to modulate AKT1-mediated LK responses in Arabidopsis. (© 2016 American Society of Plant Biologists. All Rights Reserved.)
Databáze:	MEDLINE
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