两个小麦14-3-3基因的特征、亚细胞定位及其对非生物胁迫的响应

Characterization and subcellular localization of two 14-3-3 genes and their response to abiotic stress in wheat

摘要:

为了探讨14-3-3基因在小麦逆境胁迫应答中的调控作用，利用RACE技术克隆了两个包含完整编码框的14-3-3基因 (命名为Ta14R1和Ta14R2)，其中Ta14R1 cDNA长999 bp，编码262个氨基酸，而Ta14R2 cDNA长897 bp，编码261个氨基酸。Ta14R1/Ta14R2-GFP融合载体瞬时表达结果显示，Ta14R1和Ta14R2蛋白均定位于细胞质和细胞膜，但不在叶绿体中。荧光定量PCR分析表明，Ta14R1和Ta14R2均在萌发1 d的胚芽鞘中表达量最高；在高温、低温、模拟干旱和ABA处理下，两个基因在小麦的根和叶中都受胁迫诱导而且显著上调表达，推测这两个14-3-3基因通过依赖ABA的非生物胁迫响应途径发挥作用，可能参与了小麦中高温、低温和干旱胁迫的耐受调节过程。

Abstract:

In order to investigate biological functions of the 14-3-3 genes and their response to abiotic stress, two cDNAs (designated as Ta14R1 and Ta14R2) encoding putative 14-3-3 proteins were isolated from wheat by PCR and rapid amplification of cDNA end (RACE) technique. The cDNA of Ta14R1 is 999bp and encodes a protein of 262 amino acids, while the cDNA of Ta14R2 is 897bp in length and encodes a protein of 261 amino acids. Transient expression assays using Ta14R1/Ta14R2-GFP fusion constructs indicated that Ta14R1 and Ta14R2 were located in cytoplasm and cell membrane but not in chloroplasts. Real-time quantitative (RT-PCR) analysis revealed that Ta14R1 and Ta14R2 were differentially expressed in wheat tissues and significantly up-regulated in roots and shoots 1d after germination, indicating they may play a role in process of seed germination. The expression of the two genes in roots and leaves were significantly induced by plant hormone ABA, as well as heat, cold and drought treatments, suggesting that the two 14-3-3 genes in wheat may be involved in ABA dependent stress-responding pathway and response to heat, cold and drought stress.