CKB1 is involved in abscisic acid and gibberellic acid signaling to regulate stress responses in Arabidopsis thaliana.
Casein kinase II (CK2), an evolutionarily well-conserved Ser/Thr kinase, plays critical roles in all higher organisms including plants. CKB1 is a regulatory subunit beta of CK2. In this study, homozygous T-DNA mutants (ckb1-1 and ckb1-2) and over-expression plants (35S:CKB1-1, 35S:CKB1-2) of Arabidopsis thaliana were studied to understand the role of CKB1 in abiotic stress and gibberellic acid (GA) signaling. Histochemical staining showed that although CKB1 was expressed in all organs, it had a relatively higher expression in conducting tissues. The ckb1 mutants showed reduced sensitivity to abscisic acid (ABA) during seed germination and seedling growth. The increased stomatal aperture, leaf water loss and proline accumulation were observed in ckb1 mutants. In contrast, the ckb1 mutant had increased sensitivity to polyaluminum chloride during seed germination and hypocotyl elongation. We obtained opposite results in over-expression plants. The expression levels of a number of genes in the ABA and GA regulatory network had changed. This study demonstrates that CKB1 is an ABA signaling-related gene, which subsequently influences GA metabolism, and may play a positive role in ABA signaling.
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Congying
C
Yuan
College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
Jianping
J
Ai
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Hongping
H
Chang
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Wenjun
W
Xiao
Department of Plant Pathology, Washington State University, Pullman, WA, USA.
Lu
L
Liu
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Cheng
C
Zhang
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Zhuang
Z
He
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Ji
J
Huang
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
Jinyan
J
Li
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China. gxh@hnu.edu.cn.
Xinhong
X
Guo
D000040:Abscisic Acid / Q000378:metabolism* / Q000502:physiology; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination; D005875:Gibberellins / Q000378:metabolism*; D018546:Hypocotyl / Q000254:growth & development; D009154:Mutation; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D054046:Plant Stomata / Q000502:physiology; D011392:Proline / Q000378:metabolism; D036226:Seedlings / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics*; D014867:Water / Q000502:physiology
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018744:DNA, Plant; D005875:Gibberellins; C036483:T-DNA; D014867:Water; D000040:Abscisic Acid; D011392:Proline; C007842:gibberellic acid; D047390:Casein Kinase II
ABA; Casein kinase II; GA; Over-expression; Signaling; T-DNA mutants