水稻高温、干旱响应基因OsHdr5的克隆与表达谱分析

低温、高温、干旱等非生物逆境通常会严重影响到水稻的生长及产量.为深入了解水稻逆境反应的分子机理和挖掘耐逆相关基因,本文采用Affymetrix水稻表达芯片对水稻多逆境下的全基因组表达谱进行分析,并筛选出众多表达特异基因.OsHdr5是其中一个在多个生长发育时期与组织器官中受高温、干旱诱导均显著上调的基因,用实时定量PCR方法(real-time PCR)对其表达水平进一步分析,两组结果基本吻合.用PCR方法扩增获得长为743bp的全长基因序列,其ORF区编码167个氨基酸残基,组成的肽链含有磷酸化激酶位点,形成的二级结构包含一个由6个α螺旋和2个β折叠组成的跨膜结构域,进一步分析推测其可能是叶绿体膜上与细胞跨膜信号传递相关的功能蛋白.

Cloning and Analysis of Heat-Drought Stress Related Gene OsHdr5 in Rice

Abiotie stresses including cold, drought and heat usually decrease the growth and productiv-ity of rice significantly. In order to understand the molecular mechanisms of stress responses, and to deter-mine the functions of genes involved in stress-tolerance in rice (Oryza sativa L.), gene mircoarray (Affy-metrix GeneChip Rice Genome Array) analysis was used to investigate the global genome expression pro-files of a male-sterile cuitivar, Pei'ai 64S, subjected to cold, drought or heat stresses. Gene expression profiles from leaf and panicle organs at seedling, booting and heading stages were obtained. OsHdr5 (Ory-za sativa Heat-Drought stress Responsive gene 5) was highly induced by heat and drought stresses in leaf and panicle at the two stages analyzed. Quantitative real-time PCR (real-time PCR) analysis confirmed its expression pattern revealed by the microarray analysis. We cloned this gene with full sequence of 743 bp which was found to encode a putative peptide of 167 amino acid residues in its ORF region. The predicted secondary structure of the peptide includes 6 α-helices and 2 β-sheets with transmembrane domains. BLAST search of the NCBI database for proteins sharing sequence similarity to OsHdr5 showed that it has significant sequence similarity with plasma membrane protein. We also found some potential kinase phos-phorylation sites in the protein sequence. Further analysis indicated that this protein may be a chloroplast membrane protein. Thus, OsHdr5 may be a functional gene potentially involved in cell transmembranesignaling.