富含脯氨酸和甘氨酸的蛋白基因GPRPs广泛分布于高等植物中,在植物的生长发育和逆境适应中具有重要的作用.为了克隆水稻中的OsGPRP基因,利用生物信息学分析,结合RT-PCR和测序等方法,共获得了3个水稻OsGPRP的cDNA序列,分别编码197,180,170个氨基酸,其蛋白序列均含有3个典型的植物GPRP蛋白保守结构域:N端的XYPP重复、中部富含A的疏水区和C端的HGK重复.为了初步探讨这些OsGPRP基因的功能,利用在线工具PlantCARE database分析,结果发现有3个水稻OsGPRP基因的启动子中包含有许多与植物生长发育、激素和逆境胁迫响应相关的顺式作用元件.为了进一步探究OsGPRP基因在水稻适应非生物逆境胁迫过程中的生物学功能,利用实时荧光定量PCR分析了3个OsGPRP基因在水稻幼苗适应干旱和低温胁迫过程中的响应情况.结果显示,这些OsGPRP基因对干旱和低温胁迫均有不同程度的响应;在干旱胁迫下,这些OsGPRP基因在水稻幼苗不同组织中的表达量均表现出上升的趋势,表达模式较为相似;而在低温胁迫下,其表达模式却存在一些明显的不同,其中,OsGPRP1和OsGPRP3的表达量上升,而OsGPRP2的表达量却下降.结果表明,3个OsGPRP基因在水稻适应非生物逆境中具有重要的作用.
Genes encoding glycine-and proline-rich proteins (GPRPs) are widely distributed in higher plants, playing important roles in plant growth and development,and stress adaptation. In this study,to clone rice OsG-PRPs,bioinformatics analysis combining RT-PCR and sequencing were performed.Complementary DNA (cDNA) sequences of three OsGPRPs encoding OsGPRPs with 197,180 and 170 amino acids,respectively,were obtained. Each OsGPRP encoded contained three motifs typical in plant GPRPs including an N-terminal XYPP repeat,a cen-tral hydrophobic region rich in alanine residues and a C-terminal HGK repeat.Online cis-acting regulatory element analysis against PlantCARE database were used to explore the function of these OsGPRPs.Plenty of putative cis-ele-ments related to plant growth and hormone and stress responses were identified in the promoters of these OsGPRPs. To further understand the biological function of these OsGPRPs during the process of abiotic stress adaptation,quan-titative real-time PCR (qRT-PCR) were used to analyze their responses under drought and cold stresses in rice seedlings.Responses of all three OsGPRPs to both drought and cold stresses were detected.Similar expression pat-terns with up-regulation of these OsGPRPs in response to drought were shown in different rice seedling tissues.How-ever,obviously different patterns in response to low temperature were shown with elevated OsGPRP1 and OsGPRP3 but reduced OsGPRP2 expression levels.Results indicate important adaptive roles of these three OsGPRPs to abiotic stresses in rice.