REGULATION OF TUBEROUS ROOT FORMATION BY CDK-ACTIVATING KINASE IN SWEET POTATO

克隆了cdk活化激酶和细胞周期蛋白H的两个cdna，命名为Ipoba；CDKD;1和Ipoba；进入;1,分别。Ipoba的氨基酸序列；CDKD;1含有一个atp结合位点、一个激酶活性位点和t环内保守的苏氨酸残基。Ipoba的氨基酸序列；进入;1包含n端结构域。Ipoba;CDKD;虽然该基因在所有器官中均有表达，但在块根中检测到1个转录本，表达水平最低。不同器官中转录本的相对丰度几乎没有变化。蔗糖、ABA和细胞分裂素水平在块根形成过程中增加。因此，这些信号分子对Ipoba表达的影响；CDKD;1和Ipoba；进入;1. Ipoba的表达；CDKD;1表达量增加，而Ipoba表达量增加；进入;1受蔗糖影响不显著。ABA诱导Ipoba表达；CDKD;1，而Ipoba的表达；进入;1不受ABA的影响。Ipoba的相对量；CDKD;1 mRNA被苄腺嘌呤降低，Ipoba相对量增加；进入;1 mRNA。蔗糖可拮抗苯ladenine对Ipoba的抑制作用；CDKD;1基因表达。苄基腺苷增强Ipoba的表达；进入;1 .补充蔗糖。这些结果表明，细胞增殖是通过改变蔗糖、ABA和细胞分裂素的浓度来调节cdk活化激酶和细胞周期蛋白H基因的表达来控制的。

Two cDNAs for a CDK-activating kinase and a cyclin H were cloned and designated Ipoba; CDKD; 1 and Ipoba; CycH; 1, respectively. The deduced amino acid sequences for Ipoba; CDKD; 1 contained an ATP-binding site, an kinase active-site and the conserved threonine residue within the T-loop. The deduced amino acid sequences for Ipoba; CycH; 1 contained N-terminal domain. Ipoba; CDKD; 1 transcript was detected in tuberous roots with the lowest level, although the gene was expressed in allorgans. There was little variety found among the relative abundance of transcripts in different organs. The levels of sucrose, ABA and cytokinins increase in the process of tuberous root formation. Therefore, the effect of these signal molecules on the expression of both Ipoba; CDKD; 1 and Ipoba; CycH; 1. The expression of Ipoba; CDKD; 1 increased by application of sucrose solution, while the expression of Ipoba; CycH; 1 was not significantly affected by sucrose. ABA induced the expression of Ipoba; CDKD; 1, whereas the expression of Ipoba; CycH; 1 was not influenced by ABA. The relative amount of Ipoba; CDKD; 1 mRNA was reduced by benzyladenine, while benzyladenine increased the relative amount of Ipoba; CycH; 1 mRNA. Sucrose antagonized the inhibitory effect of benzyladenine for Ipoba; CDKD; 1 gene expression. Benzyladenine enhanced the expression of Ipoba; CycH; 1 when sucrose was supplemented. These results suggested that cell proliferation was controlled via regulation of CDK-activating kinase and cyclin H gene expression by alterations in the concentration of sucrose, ABA and cytokinin.