“蜀脆枣”果实发育过程中糖酸代谢相关基因表达分析

Analysis of Sugar and Organic Acid Metabolism-related Genes Expression during Development of Ziziphus jujuba cv.“Shucuizao”Fruits

以“蜀脆枣”为试验材料,采用HPLC测定果实发育过程中可溶性糖和有机酸组分及含量,利用qRT-PCR分析糖酸代谢相关基因的表达差异。结果表明,“蜀脆枣”果实发育前中期以积累葡萄糖和果糖为主,白熟期蔗糖含量迅速上升,至成熟期其含量占总糖的73.17%。果实发育过程中,苹果酸含量始终最高,成熟期达3.30 mg/g,占总酸的65.74%;柠檬酸含量次之,占成熟期总酸的31.08%;酒石酸含量最低。糖酸代谢基因表达及相关性分析表明,蔗糖含量与Zj SS3、Zj SPS1、Zj SPS2的表达呈极显著正相关,与Zjv INV2的表达显著负相关,果实发育后期Zj SS3、Zj SPS1、Zj SPS2的高表达和Zjv INV2的低表达共同促进成熟期蔗糖的迅速积累,是影响果实糖代谢的关键因素。Zj PEPC1的表达与苹果酸含量极显著正相关,其高表达是果实苹果酸积累的重要因素;Zj PEPCK1-1的表达与柠檬酸含量呈极显著正相关,是调控柠檬酸积累的关键基因。

Taking“Shucuizao”as material,the contents of soluble sugars and organic acid components in Ziziphus jujuba cv.“Shucuizao”fruits during its development were determined by using HPLC,and the differential expression levels of sugar and organic acid metabolism-related genes were analyzed using qRT-PCR.The results showed that glucose and fructose accumulated mainly at the early and middle stages of fruit development.The sucrose content increased rapidly at white ripening stage,reaching 107.43 mg/g at mature stage,which accounted for 73.17%of the total sugar.Among organic acid components,the malic acid content was the highest,reaching 3.30 mg/g at the mature stage,which accounted for 65.74%of the total organic acid.Citric acid content was the second,accounting for 31.08%of the total acid at mature stage.The tartaric acid content was the lowest.Gene expression and correlation analysis showed that the sucrose content had significantly positive correlation with the expression of Zj SS3,Zj SPS1,and Zj SPS2,and negative correlation with the expression of Zj vINV2.The up-regulation of Zj SS3,Zj SPS1,and Zj SPS2 and the down-regulation of Zj vINV2 joint lypromoted rapid sucrose accumulation during the mature stage,which was the key factor affecting sugar metabolism in fruits.Zj PEPC1 had significantly positive correlation with the malic acid content and was the main factor to affect its changes in fruits.The expression levels of Zj PEPCK1-1 had significantly positive correlation with the citric acid content and regulated citric acid accumulation in fruits.