番茄SlCBL1基因的克隆与生物学功能初探

Isolation,relative expression and functional identification of SlCBL1 gene

类钙调磷酸酶B亚基蛋白(calcineurin B-like proteins,CBLs)是植物中一类特殊的钙离子感受器,在应对多种生物与非生物胁迫反应中起到十分重要的作用.目前有关CBLs基因生物学功能研究主要集中于拟南芥与水稻,番茄中相关功能报道较少.研究利用同源克隆方法,从番茄中分离出1个SlCBL1基因;应用半定量PCR技术研究SlCBL1基因在不同组织的相对表达水平,将该基因构建超表达载体并遗传转化本氏烟.结果表明:SlCBL1基因cDNA全长639 bp,编码212个氨基酸残基;基因组全长5000 bp,包含8个外显子及7个内含子;推导的氨基酸序列与烟草NtCBL1蛋白相似度最高,且包含CBL蛋白结合Ca2+所必需的4个EF手型结构.SlCBL1在番茄不同组织中均有表达,但在营养器官中的表达最高,并且响应多种非生物胁迫.与对照相比,过超量表达SlCBL1基因的本氏烟株系提高了对盐胁迫的抗性.上述研究表明,番茄SlCBL1基因能够响应并拮抗非生物胁迫,这为进一步研究CBL1生物学功能提供了基础.

Plant calcineurin B-like proteins(CBLs),a specific Ca2+sensor,interacted with CBL-interacting protein kinase(CIPK),played fundamental roles in responding to biotic and abiotic stress.The recent researches about CBLs were mainly focused on Arabidopsis thaliana and Oryza sativa,however,its biological functions in tomato(Solanum lycopersicum)was less exploited.SlCBL1 gene was isolated from tomato cDNA and genomic DNA,and its sequence characterization,relative expression level,and biological functions were identified.The results showed that the open reading frame of SlCBL1 gene was 639 bp for a putative protein of 212 amino acids,and the genomic sequence of SlCBL1 was 5000 bp,including 8 exons and 7 introns.The deduced amino acid sequence was similar to that of tobacco NtCBL1,and contained 4 conserve EF domains.RT-PCR analysis showed that SlCBL1 was widely expressed in different tissues,and responded to various abiotic stress.Moreover,overexpression of SlCBL1 gene in Nicotiana benthamiana lines could increase the tolerance to salt stress,indicated SlCBL1 was involved against abiotic stresses,which provides clues for further study its function.