中文摘要：

丝氨酸/苏氨酸蛋白磷酸酶6亚基（catalytic subunits of Ser/Thr protein phosphatase 6,PP6C）是PP6全酶的催化亚基。在模式植物拟南芥中的研究表明,PP6C参与生长素极性运输、脱落酸信号转导和光信号转导途径介导的开花调控。为了明确玉米丝氨酸/苏氨酸蛋白磷酸酶6亚基（ZmPP6C）的蛋白结构特征与同源蛋白间的进化关系,采用RT-PCR方法克隆了ZmPP6C的全长基因。序列分析表明,ZmPP6C开放阅读框为912个核苷酸,编码303个氨基酸残基,包含PP2A的催化亚基PP2Ac结构域;系统进化树分析表明,PP6C蛋白在进化上较为保守,并且与高粱的PP6C蛋白相似性更高。对玉米自交系B73的ZmPP6C基因进行器官特异性表达分析表明,其表达量在成株期叶片中最高,是根中的7.9倍;ZmPP6C能够响应不同光质处理,且受远红光和红光的影响较大;也能响应长日和短日处理,在长日条件下的光照和黑暗阶段各有一个明显的表达高峰,在短日条件下的光照和黑暗阶段分别有2个和3个表达峰值;同时,ZmPP6C还响应高渗透、盐渍和淹水等胁迫处理,出现明显的上调表达。结果表明,ZmPP6C在玉米光信号转导、开花诱导与胁迫应答中发挥重要作用,其分子与生化机制值得进一步探讨。

英文摘要：

PP6C is the catalytic subunits of Ser/Thr protein phosphatase 6 （PP6） gene, which plays important roles in auxin transport polarity, ABA （abscisic acid） signal transduction, flowering time control though light signaling pathway. To clarify structural characteristics of PP6C protein and the evolution relationships among plant PP6C homologs, we cloned ZmPP6C gene by RT-PCR. The open reading flame （ORF） of ZmPP6C possesses 912 nucleotides and encodes 303 amino acid residues with one PP2Ac domain （the catalytic subunits of Ser/Thr protein phosphatase 2A）. Phylogenetic analysis indicated that ZmPP6C belongs to the same branch with the PP6C of Sorghum bicolor, and shows high similarity to all PP6C proteins from other monocotyledons and dicotyledons. Further quantitative RT-PCR （qRT-PCR） assays indicated that ZmPP6C was highly expressed in leaf and lowly in stem, stamen, pulvinus, sheath, and pedical. ZmPP6C transcription abundances could respond to different light and circadian treatments （both long-day and short-day conditions）, especially to the light transitions from the dark to far-red or red light condition. In addition, ZmPP6C transcription abundances were up-regulated by high osmosis, high salt and water logging. Our results suggested that ZmPP6C may be involved in light signaling pathway, flowering time control, and abiotic stress response in maize, and its roles in crop improvement are worthy of more exploration in the future.