苹果MdCRTISO基因的鉴定与表达模式分析

Identification and Expression Analysis of MdCRTISO Gene in Apple

类胡萝卜素异构酶(CRTISO)是类胡萝卜素生物合成途径中催化番茄红素由顺式结构向反式结构转变的关键异构酶,在高等植物和藻类的类胡萝卜素合成途径中发挥着重要作用.从金冠苹果叶片中克隆了MdCRTISO基因,采用生物信息学方法对其编码蛋白的理化性质、保守结构域、亲/疏水性及系统发育关系等进行了分析,并利用实时荧光定量PCR技术检测MdCRTISO基因在苹果不同组织和不同胁迫下的表达模式.结果显示:MdCRTISO基因编码区长度为2028 bp,编码675个氨基酸,该基因的编码蛋白分子量为74.331 kDa,为稳定的亲水性蛋白,定位于叶绿体中.MdCRTISO基因在苹果根、叶、茎、花和果实中均有表达,其中以在果实和叶片中的表达最为显著.在盐、碱和低温胁迫下,该基因表达显著上调,在ABA处理、PEG胁迫下,该基因表达显著下调,表明该基因能响应多种不同的逆境胁迫.

Carotenoid isomerase(CRTISO)is a key isomerase that catalyzes the conversion of cis-lycopene to all-trans lycopene in the carotenoid biosynthesis pathway,and plays an important role in higher plants and algae.The MdCRTISO gene was cloned from the leaves of‘Golden Delicious’apple,and the physicochemical properties,conserved domains,affinity/hydrophobicity and phylogenetic relationship of the encoded protein were analyzed by the bioinformatics methods.The expression of MdCRTISO gene in different tissues and under different stresses were detected by Real-time PCR.The results showed that the coding region of MdCRTISO gene is 2029 bp in length,encoding 675 amino acids.The encoded protein of this gene has a molecular weight of 74.331 kDa,which is a stable hydrophilic protein.The MdCRTISO gene is expressed in various tissues such as roots,leaves,stems,flowers and fruits.The expression level is significantly higher in fruits and leaves compared to other tissues.The expression level of this gene is significantly up-regulated under salt,alkali,and low temperature stresses,and significantly down-regulated under ABA treatment and PEG stress,indicating that the gene could respond to a variety of different stresses.