菜豆金黄荚色产生的生化机制研究

选用菜豆金黄色豆荚品种‘A18’和绿色豆荚品种‘热那亚’为试验材料,通过测定豆荚发育过程中荚壁的叶绿素、类胡萝卜素和叶绿素合成途径中相关代谢物质含量,探讨菜豆金黄荚色的形成机理。结果表明,嫩荚呈现金黄色是由于叶绿素缺乏,推测是因为叶绿素酸酯a(chlorophyllide a)的合成受阻导致;利用荧光定量PCR对叶绿素生物合成相关基因的表达进行分析,发现在‘A18’中CHLM和DVR的表达量从花后12 d开始下降,但CHLP、CHLG和CAO的表达量在多个时间点高于‘热那亚’,这说明虽然叶绿素酸酯a合成受阻,但叶绿素的合成仍然能进行。

Biochemical Mechanism of Golden Yellow Pod Color in Common Bean

Golden yellow bean pod‘A18’and green bean‘Genoa’were chosen as experimental materials to study the expressing mechanism of color in golden bean pods. The formation mechanism of the golden pod color of kidney bean was studied by determining the amount of related metabolin in the synthetic pathway of chlorophyll，carotenoid，and chlorophyll during pod development in its wall. The results indicated the golden color of tender pod was resulted from the lack of chlorophyll content，which was speculated by the inhibition of chlorophyllide a synthesis. The expression pattern of chlorophyll biosynthesis-related genes was analyzed by real-time PCR. Indeed，the analysis suggested the expression levels of CHLM and DVR decreased in‘A18’from the 12th day after flowering. While the expression levels of CHLP，CHLG and CAO were higher than those in‘Genoa’at multiple time points，indicating that although chlorophyllide a synthesis is blocked，chlorophyll synthesis is still active.