番茄复三螺旋基因响应外源激素和非生物胁迫的研究

复三螺旋(double trihelix)基因在植物形态建成和植株抗逆性方面发挥关键作用。该研究以番茄自交品种AC⁺⁺为试验材料，运用生物信息学方法与qRT PCR技术对5个复三螺旋成员(SlGTL1~SlGTL5)在番茄体内不同器官的表达模式、以及基因对激素与非生物胁迫的响应进行表达分析，以探讨番茄复三螺旋基因的功能。结果表明：(1)生物信息学分析显示，番茄中含有5个复三螺旋基因(SlGTL1~SlGTL5)；进化树分析表明，番茄复三螺旋基因具有物种特异性。(2)qRT PCR分析显示，番茄SlGTL3基因在根和茎中特异表达，其他4个基因均在果实中较高表达，表明不同番茄复三螺旋基因的表达具有组织特异性。(3)激素诱导表达结果显示，SlGTL1只响应ABA(1种)激素，而SlGTL5基因可响应4种激素，且速度较快。(4)非生物胁迫诱导证实，SlGTL3、SlGTL5基因可响应盐胁迫，SlGTL3~SlGTL5基因可响应极端温度，SlGTL3和SlGTL4基因可响应机械损伤；SlGTL1、SlGTL4和SlGTL5可响应脱水胁迫。研究认为，SlGTL3的功能可能与植株形态建成和非生物胁迫有关，其他4个基因的功能可能与果实的发育有关；推测SlGTL1可能与ABA信号途径有关，SlGTL5快速响应多种激素，可能位于信息传递的节点，其功能可能与信号传递有关。

Responses of Double trihelix Genes to Phytohormones and Abiotic Stress in Tomato

Double trihelix genes play important roles in promoting morphogenesis and resistance to stress. In order to identify their function in tomato, we tested the expression patterns and responses of five double trihelix genes in different tissues, to phytohormones and abiotic stress by bioinformatics and expression analysis. Experimental results showed that: (1) five members and their species specificity were determined in tomato by bioinformatics analysis. (2) Expression pattern analysis showed that SlGTL3 specifically expressed in root and stem and others high in fruits by means of qRT PCR, suggesting the tissues specificity of double trihelix genes in AC⁺⁺. (3) Hormone induced test displayed that SlGTL5 responds to four kind of phyhormones very quickly and SlGTL1 is only induced by ABA. (4) It was proved that expression levels of SlGTL3 and SlGTL5 can be altered by salt, SlGTL3-SlGTL5 by extreme temperature, SlGTL3 and SlGTL5 by mechanical wounding, and SlGTL1, SlGTL4, SlGTL5 by dehydration. The results indicated that SlGTL3 function is correlated with plant morphogenesis and abiotic stress, while others to fruits development. Our study also suggested that SlGTL1 is related with ABA signaling and SlGTL5 with signaling transmission as the result of its fast responses to various exogenous hormones.