为探讨草莓果实发育过程ABA积累的酶学调控机制,文章以花后1~4周的‘杜克拉’草莓7个时期果肉为试材,利用实时荧光定量PCR分析ABA积累关键酶基因FaNCED1和FaBG1转录水平。结果表明,在整个草摹果实发育过程中,果肉中FaNCED1基因表达水平明显地分为两个持续上升阶段,即从小绿期至白熟期和始红期至全红期,但二者之间还存在一个短暂下降期,即白熟期至始红期;果肉中FaBG1基因表达水平呈逐渐降低的趋势。结合果肉中ABA含量分析发现,FaNCED1基因转录水平呈现与ABA水平相似的变化趋势。本研究主要得出以下结论:(1)退绿和着色是草莓果实发育成熟过程中两个突出事件;(2)果肉中ABA水平两次持续快速积累分别与草莓果实退绿和着色相偶联;(5)果肉中ABA含量主要由FaNCED1基因决定,而与FaBG1基因关系不大。以上结果为从分子水平调控草莓果实中ABA含量,进而调控果实的发育奠定研究基础。
To explore the enzymatic regulatory mechanism of ABA level during strawberry fruit development, receptacle of 'Fugilia' strawberries (Fragaria xananassa Duch.) was used to detect the expression levels of FaNCEDI and FaBGI genes by real-time quantitative PCR during 1-4 week after flowering at seven stages of fruit development. The results showed that the mRNA expression level of FaNCED1 gene has two rapid accumulation stages, namely, from small green stage to white stage and initial red stage to full red stage, and there is a decreasing stage between them, namely from white stage to initial red stage. In contrast, the expression level of FaBG1 gene showed a gradually decreasing trends. Combinational analysis of ABA contents in receptacle showed that the mRNA expression level of FaNCED1 gene has a similar changing trends with ABA contents during strawberry fruit development.The conclusion is that, (1)Fading green and coloring up are marked events during strawberry fruit development; (2)The two rapid accumulation of ABA is coupled with fruit fading green and coloring up, respectively; (3)ABA accumulation is mainly resulted from FaNCED1 gene high expression, has little relationship with FaBG1 gene. The results of this study might provide the foundation on manipulation of the ABA content at molecular level, further on manipulating the ripening time and extent of strawberry fruits.