Yuan Congying, Ai Jianping, Chang Hongping, Xiao Wenjun, Liu Lu, Zhang Cheng, He Zhuang, Huang Ji, Li Jinyan, Guo Xinhong
College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, People's Republic of China.
College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
J Plant Res. 2017 May;130(3):587-598. doi: 10.1007/s10265-017-0924-6. Epub 2017 Mar 24.
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.
酪蛋白激酶II（CK2）是一种在进化上高度保守的丝氨酸/苏氨酸激酶，在包括植物在内的所有高等生物中都发挥着关键作用。CKB1是CK2的调节亚基β。在本研究中，对拟南芥的纯合T-DNA突变体（ckb1-1和ckb1-2）和过表达植株（35S:CKB1-1、35S:CKB1-2）进行了研究，以了解CKB1在非生物胁迫和赤霉素（GA）信号传导中的作用。组织化学染色显示，尽管CKB1在所有器官中均有表达，但在输导组织中的表达相对较高。ckb1突变体在种子萌发和幼苗生长过程中对脱落酸（ABA）的敏感性降低。在ckb1突变体中观察到气孔孔径增大、叶片水分流失和脯氨酸积累增加。相反，ckb1突变体在种子萌发和下胚轴伸长过程中对聚氯化铝的敏感性增加。我们在过表达植株中得到了相反的结果。ABA和GA调控网络中一些基因的表达水平发生了变化。本研究表明，CKB1是一个与ABA信号相关的基因，随后影响GA代谢，并可能在ABA信号传导中发挥积极作用。
