CPPU处理猕猴桃常温贮藏过程中果实糖含量相关基因的表达分析

Gene Expression Related to Sugar Content During Storage of Kiwifruit under Room Temperature with CPPU Treatment

为了解析采前CPPU处理的猕猴桃果实贮藏性与未处理果实的差异及相关的分子调控机制,以清水为对照,评价了盛花后用20 mg/L CPPU处理果实在常温贮藏下可溶性固形物、可滴定酸及可溶性糖含量的变化,并用转录组分析鉴定出与可溶性糖变化相关的候选基因。结果表明,无论处理还是对照,可溶性糖含量在贮藏过程中呈逐渐上升趋势,但CPPU处理果实的可溶性糖含量始终低于对照果实。转录组分析表明,CPPU处理抑制了淀粉和蔗糖代谢中的基因Achn087691(编码磷酸己糖异构酶)以及果糖和甘露糖代谢中基因Achn203191(编码磷酸丙糖异构酶)的表达,并促进淀粉和蔗糖代谢中基因Achn069851(编码己糖激酶)前期表达,但对基因Achn161931(编码尿苷二磷酸葡萄糖脱氢酶)、基因Achn206141(编码尿苷二磷酸-葡萄糖醛酸酯-4-表异构酶)和基因Achn295291(编码果胶甲酯酶)表现为前期抑制、中期促进、后期抑制。由此推测,20 mg/L CPPU处理明显影响了徐香猕猴桃果实中可溶性糖含量及糖代谢相关基因的表达,致使果实常温贮藏过程中可溶性固形物和可溶性糖含量降低,且提前软化。

In order to study the regulation mechanism in the sugar meta bolismin of CPPU treated kiwifruit during the storage,this study analyzed the differences in total soluble solids( TSS),titratable acid( TA) and soluble sugar conten( SSC) between 20 mg/L CPPU-treated and water-treated kiwifruits after two,four,six,or eight days of storage,and differential gene expression related to these compounds using high-throughput sequencing. The study found that,regardless of the treatment or the control,the soluble sugar content gradually increased during the storage,but the soluble sugar content of the CPPU-treated fruit was always lower than that of the control fruit. CPPU treatment inhibited the expression of gene Achn087691( glucose-6-phosphate isomerase) in starch and sucrose metabolism and Achn203191( triosephosphate isomeras) in fructose and mannose metabolism, and promoted early expression of gene Achn069851( hexokinase) in starch and sucrose metabolism,but showed early inhibition,medium-term promotion,late suppression of gene Achn161931( UDP-glucose 6-dehydrogenase),gene Achn206141( udp-galactose-4-epimerase),and gene Achn295291( pectin methylesterase). It was speculated that 20 mg/L CPPU treatment significantly affected the soluble sugar content and sugar metabolism related gene expression in kiwifruit( Actinidia deliciosa Xuxiang),resulting in a decrease in TSS and SSC during storage at room temperature and accelerated the softening of fruit.