麻疯树雌雄花中MADS-BOX基因的表达分析

摘要

麻疯树(Jatropha curcas)种子含油率高,种子中的油类物质可作为生物柴油被开发和利用,是极具潜力的生物质能源树种之一.麻疯树雌雄异花,在自然条件下雄花数量通常远远大于雌花,这大大限制了种子和油的产量,因此开展麻疯树性别分化与花发育分子机理的研究具有重要意义.该研究选取10个麻疯树的MADS?BOX基因(JcAGL1,JcAGL6,JcAGL9,JcAGL11,JcAGL15,JcAGL61-3,JcAGL62-1,JcAGL62-6,JcA-GL62-7,JcAGL80-2),提取麻疯树早期发育各个阶段的雌雄花总RNA,并反转录成cDNA,采用实时荧光定量方法,探索早期发育不同阶段的麻疯树雌雄花目的基因的表达情况.结果表明:目的基因在发育起始的雌雄花中的表达具有差异,比如JcAGL6和JcAGL15在雄花中表达量要高于雌花,而JcAGL1,JcAGL9和JcAGL11在雌花中的表达量要高于雄花,这说明花原基中目的基因表达会直接或间接决定性别分化的方向;在之后的发育过程中,目的基因的表达情况在雌雄花中有所不同:随着花的发育,目的基因在雌雄花中的表达量变化存在差别,这反应出麻疯树雌雄花发育中目的基因表达模式上的差异;另外,也能看出在此过程中各个目的基因又发挥着不同的功能.该研究结果为进一步探究麻疯树雌雄花发育相关基因的表达提供了理论依据,为了解麻疯树性别分化和花发育的分子机理奠定了基础.%The members of the MADS?BOX transcription factor family play essential roles in sex differentiation and flow?er development in many plants. Jatropha curcas is a monoecious plant,which has been seen as one of the potential bio?mass energy tree species because oil content in the seeds is high and it can be used as biodiesel.However,seed oil pro?duction is mainly depended on seed yield,which is restricted by the low ratio of female flowers to male flowers. So the number of female flowers is one of the key factors to increase seed yield, and it is of great significance to analyze the causes of the differences in the number of female and male flowers and to study the molecular mechanisms of sex differen?tiation and flower development in J. curcas. In order to investigate the molecular mechanisms of sex differentiation and flower development,we chose ten members of MADS?BOX family gene in J. curcas(JcAGL1, JcAGL6, JcAGL9, JcA-GL11,JcAGL15,JcAGL61-3,JcAGL62-1,JcAGL62-6,JcAGL62-7,JcAGL80-2),total RNA were extracted from female and male flowers at different stages of early developments,cDNA were synthesized by using these RNA,and qRT?PCR method was used to detect and analyze the expression of these genes in female and male flowers. The results were de?scribed as below:The expression of target genes was different between pistillate and staminate at the beginning of devel?opment,for example,the expression of JcAGL6 and JcAGL15 in staminate flowers was higher than that in pistillate flow?ers,while the expression of JcAGL1,JcAGL9 and JcAGL11 in pistillate flowers was higher than that in staminate flowers, showing that the expression of target genes in floral primordia directly or indirectly determines the direction of sex differ?entiation. Expression level of target genes was different between pistillate and staminate flowers in later development:With flowers development,the variation of target genes expression in pistillate and staminate flowers was different,indi?cating different expression patterns of target genes between pistillate and staminate flowers. In addition, it can be seen that each target gene has different functions in the process. Our results provide theory evidence to further study the ex?pression of genes related to the development of pistillate and staminate flowers,and lay the foundation for understanding the molecular mechanism of sex differentiation and flower development in J. curcas.