期刊
JOURNAL OF EXPERIMENTAL BOTANY
卷 65, 期 15, 页码 4159-4175出版社
OXFORD UNIV PRESS
DOI: 10.1093/jxb/eru190
关键词
ABA insensitivity; gene expression; knockout mutation; plastid casein kinase 2; retrograde signalling; thermotolerance
资金
- National Natural Science Foundation of China [31071076, 30871325, 30600368, 91317312]
- Program for New Century Excellent Talents in University [NCET-10-0363]
- Excellent Youth Foundation of Hunan Province [11JJ1005]
- PhD Programs Foundation of Ministry of Education of China [20130161110005]
- Scientific Research Foundation for the Returned Overseas Chinese Scholars
- State Education Ministry [(2011) 1139]
Plastid casein kinase 2 (CK2) is a major Ser/Thr-specific enzyme for protein phosphorylation in the chloroplast stroma and its kinase activity is regulated by redox signals. To understand the role of CK2 phosphorylation of chloroplast proteins in abiotic stress signalling, an Arabidopsis plastid CK2 (CKA4) knockout mutant was investigated in terms of the plant response to abscisic acid (ABA) and heat stress. CKA4 expression was upregulated by ABA and heat treatment. The cka4 mutant showed reduced sensitivity to ABA during seed germination and seedling growth, and increased stomatal aperture and leaf water loss with a slightly reduced leaf ABA level. The cka4 mutant was more sensitive to heat stress than the wild-type Columbia-0. The expression levels of a number of genes in the ABA regulatory network were reduced in the cka4 mutant. Many heat-upregulated genes (heat-shock factors and heat-shock proteins) were also reduced in the cka4 mutant. The cka4 mutant showed reduced expression levels of plastid-encoded RNA polymerase target genes (atpB and psbA). CKA4 knockout mutation also resulted in a reduction in expression of some critical genes (PTM, ABI4, and PRS1) involved in retrograde signalling from the chloroplast to the nucleus. Similar results were observed in mutant plants with the knockout mutation in both CKA4 and CKA3, which encodes a nuclear CK2 alpha 3 subunit. CKA3 expression was not responsive to ABA and heat stress. These results suggest that CKA4 is an enhancing factor in abiotic stress signalling through modulating the expression of some molecular players in retrograde signalling.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据