施氮时期对酿酒葡萄叶片氮代谢酶及相关基因表达的影响

Effects of Nitrogen Metabolism Enzymes and Related Gene Expression in Leaves of Vitis vinifera during Nitrogen Application Period

以10年生‘蛇龙珠’葡萄为材料,在萌芽期(S1)、新梢旺长期(S2)、开花期(S3)、果实第一次膨大期(S4)、副梢生长旺期(S5)和果实第二次膨大期(S6)分别一次性施入尿素300kg·hm-2,以不施氮肥为对照(CK),分析了花前5d(DBF5)、花后25d(DAF25)、花后55d(DAF55)和花后85d(DAF85)叶片的各项指标,以明确氮素施用时期对葡萄叶片氮代谢的调控与影响。结果表明:(1)S1和S2处理葡萄叶片中总氮及可溶性蛋白含量在DAF25时显著增加。(2)S3和S4处理的NR及GS活性在DAF85时显著高于其他处理;在DAF25时,S1和S2处理的GOGAT活性,以及S3和S4处理的GDH活性均显著高于同期对照和其他施肥处理。(3)各施肥处理叶片VvNR表达水平在不同时期均高于同期对照,S3处理VvNR表达水平在DAF25和DAF85时分别为对照的3.4倍和2.7倍;S3和S4处理的VvGS表达水平分别在DAF55和DAF85时达到最高值,S3处理的VvGOGAT和S4处理的VvGDH表达水平在DAF55和DAF85均显著高于其他处理,S3处理的VvGDH表达水平在DAF55和DAF85仅次于S4处理。研究表明,氮素通过诱导叶片氮素代谢基因的响应,从而调控叶片中氮素代谢酶活性增加,促进了氮素的积累,S3和S4处理在不同时期氮代谢酶活性和对应的基因表达水平均较高,更有利于叶片中氮素的转化和代谢。

This study is based on the10year old Cabernet‘Gernischet’,which was treated with300kg·hm-2urea at the germination stage(S1),new shoot vigorous growth stage(S2),flowering stage(S3),the first expansion stage of fruit(S4),secondary shoot vigorous growth stage(S5)and the second expansion stage of fruit(S6).No nitrogen fertilizer was used as the control(CK).The indicators in leaves were analyzed at5days before flowering(DBF5),25days after flowering(DAF25),55days after flowering(DAF55),and85days after flowering(DAF85),for clarifying the regulation and influence of nitrogen application period on nitrogen metabolism in grape leaves.The results showed that:(1)S1and S2treatments significantly increased the total nitrogen and soluble protein contents in leaves at DAF25.(2)The activities of NR and GS in S3and S4treatments were significantly higher than those in other treatments at DAF85.At DAF25,the GOGAT activities of S1and S2were0.29and0.33μmol·g-1·min-1,respectively.The GDH activities of S3and S4significantly higher than those of control and other fertilization treatments,which were225.0and227.3U·g-1,respectively.(3)Quantitative analysis showed that the expression level of VvNR was higher than that of control at different stages,and was3.4times and2.7times higher than that of control in S3at DAF25and DAF85,respectively.The expression levels of VvGS in S3and S4were the highest at DAF55and DAF85,respectively.The expression level of VvGOGAT in S3and VvGDH in S4were significantly higher than that of other treatments at DAF55and DAF85.In addition,the expression level of VvGDH in S3at DAF55and DAF85was second only to S4.Correlation analysis showed that there was a linear relationship among nitrogen content,nitrogen metabolism enzyme activities and the expression levels of regulatory genes.Therefore,nitrogen could induce the response of leaf nitrogen metabolism genes,thereby regulating nitrogen metabolism in leaves.S3and S4treatments were higher in the activities of nitrogen metabolizing enzymes and the corresponding gene relative expression levels in different periods,and were more conducive to the transformation and metabolism of nitrogen in the leaves.This study could provide some support for the scientific application of nitrogen fertilizer.