Arabidopsis CK2 family gene CKB3 involved in abscisic acid signaling

Abstract CKB3 is a regulatory (beta) subunit of CK2. In this study Arabidopsis thaliana homozygous T-DNA mutant ckb3 was studied to understand the role of CKB3 in abscisic acid (ABA) signaling. The results shown: CKB3 was expressed in all organs and the highest expression in the seeds, followed by the root. During seed germination and root growth the ckb3 mutant showed reduced sensitivity to ABA. The ckb3 mutant had more stomatal opening and increased proline accumulation and leaf water loss. The expression levels of number of genes in the ABA regulatory network had changed. This study demonstrates that CKB3 is an ABA signaling-related gene and may play a positive role in ABA signaling.摘要：CKB3是酪蛋白激酶2（CK2）的调控型β亚基。本研究以拟南芥（Arabidopsis thaliana）纯合T-DNA插入突变体ckb3为实验材料，探究CKB3在脱落酸（abscisic acid, ABA）信号通路中的生物学功能。实验结果表明：CKB3在拟南芥各器官中均有表达，其中种子内表达量最高，根系次之。在种子萌发与根系生长阶段，ckb3突变体对ABA的敏感性显著降低。ckb3突变体的气孔开放程度更高，脯氨酸积累量与叶片水分流失量均有所升高。ABA调控网络内多个基因的表达水平发生显著变化。本研究证实，CKB3是一类与ABA信号通路相关的基因，并可能在ABA信号通路中发挥正向调控作用。