NAA对葡萄果实中糖酸含量及相关基因表达的影响

Effect of NAA Treatment on Sugar Acid Content and Related Gene Expression in Grape Berries

以‘里扎马特’葡萄为试材,于果实始熟期分别利用50、100和200 mg·L^(-1)的NAA喷施果实。结果表明:NAA处理可显著抑制果实中葡萄糖、果糖、蔗糖以及可溶性总糖的积累,阻碍酒石酸、苹果酸、柠檬酸、草酸及总酸的降解,且以200 mg·L^(-1)处理最为显著,但处理并未改变果实中的糖酸组分。NAA处理还可显著抑制可溶性糖代谢关键基因SS和SPS的表达,但对NI表现为前、中期抑制,后期促进,对FRK表现为前、中期促进,后期抑制。对于有机酸代谢相关基因而言,NAA处理显著促进MDH和PEPC的表达,抑制ME基因的表达,但对IDH基因表达的影响并不显著。由此推断,外源NAA处理抑制果实成熟的原因可能在于其改变了部分糖酸代谢相关基因的表达,进而阻碍了可溶性糖的积累和有机酸酸的降解。

‘Rizamat'grape berries were treated with 50,100 and 200 mg · L^(-1) NAA separately at veraison. The results showed that the accumulation of glucose,fructose,sucrose and soluble sugar was significantly inhibited,and the degradation of tartaric acid,malic acid,citric acid,oxalic acid and total acid was also hindered by the treatment of NAA. Comparing three different treatments,the effect of NAA with 200 mg · L^(-1) was the most remarkable,but sugar and acid compositions were not changed. The expression of SS and SPS,which were the soluble sugar-metabolism related genes,was also inhibited by the treatment of NAA. But the expression of NI was inhibited in prometaphase and promoted at later stage. The expression of FRK was contrary to the NI. For organic acid related genes,the expression of MDH and PEPC was promoted by the treatment of NAA,and the expression of ME was inhibited. But the effect on the expression of IDH was not significant. Therefore,we speculate that the reason for delaying fruit ripening of exogenous NAA is that parts of the sucrose and acid-metabolism related genes expression are changed,and then the accumulation of sugar and degradation of acid are hindered.