Molecular Cloning of ZmPP6C Gene and Its Ex-pression Patterns in Response to Light and Stress Treatments in Maize( Zea mays L.)

Abstract

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 frame (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 第 2期 原换换等: 玉米 ZmPP6C基因的克隆及其响应光质和胁迫处理的表达模式分析 171 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.