《植物生理学报》 2015, 51(4): 436-444

根域限制对转色期‘巨玫瑰’葡萄氮水平和氮代谢关键酶基因表达的影响

虞秀明^1,2, 李节法¹, 王博³, 王磊¹, 王世平^1,*

¹上海交通大学农业与生物学院, 上海200240; ²上海市林业总站, 上海200072; ³广西大学农学院, 广西南宁530004

通信作者：王世平；E-mail: fruit@sjtu.edu.cn；Tel: 021-34205956

摘　要：

为探讨根域限制影响葡萄树氮代谢的分子机制, 以二年生‘巨玫瑰‘葡萄为试材, 研究根域限制对其转色期不同组织器官中氮水平和氮代谢关键酶基因(NR、NiR、GS1-1、GS1-2、GS2、Fd-GOGAT和NADH-GOGAT)转录水平的影响。结果表明, 根域限制导致转色期葡萄的新梢生长显著受到抑制, 但显著促进果实生长和果实品质的提高。根域限制导致(NO₂^－+NO₃^－)-N、NH₄⁺－N和全氮含量在转色期叶片、叶柄和褐根中显著下降, 而在白根中却显著提高。根域限制栽培条件下叶柄、白根和褐根中的可溶性蛋白含量极显著高于对照。根域限制栽培条件下叶片和叶柄中的谷氨酰胺合成酶(GS)活性均显著低于对照, 白根和褐根中的GS活性却高于对照。根域限制下转色期叶片和叶柄(光合组织)中氮代谢关键酶基因的表达水平低于对照, 而根域限制却导致这些基因在白根中表达均上调, 尤其是白根和褐根中的GS基因。根域限制栽培条件下转色期NO₃^－还原和NH₄⁺同化过程发生在葡萄地下部分(白根)内比例上升, 而在地上部分(叶片和叶柄)内进行的比例显著下降。根域限制导致葡萄叶片和叶柄中氮代谢关键酶基因表达显著下调是根域限制对新梢营养生长产生抑制效应的重要因素。

关键词：根域限制; 葡萄; 氮代谢; 氮素水平; 基因表达

收稿：2014-12-08   修定：2015-03-23

资助：国家自然科学基金(30871695)。

Effects of Root Restriction on Nitrogen Levels and Expression of Genes Involved in Nitrogen Metabolism in ‘Jumeigui’ Grapevines (Vitis vinifera×V. labrusca) at Veraison

YU Xiu-Ming^1,2, LI Jie-Fa¹, WANG Bo³, WANG Lei¹, WANG Shi-Ping^1,*

¹School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; ²Shanghai Forestry Station, Shanghai 200072, China; ³Agricultural College, Guangxi University, Nanning, Guangxi 530004, China

Corresponding author: WANG Shi-Ping; E-mail: fruit@sjtu.edu.cn; Tel: 021-34205956

Abstract:

The aim of this study was to investigate the molecular mechanism of nitrogen metabolism in grapevines (Vitis vinifera×V. labrusca) in response to root restriction. The two-year-old ‘Jumeigui’ grape cultivars were used to study changes of nitrogen levels and the transcription of nitrogen metabolism enzyme genes in different organs under root restriction at veraison. The results showed that the shoot growth was significantly inhibited, whereas the berry growth and berry quality were enhanced under root restriction at veraison. The root restriction decreased the (NO₂^－+NO₃^－)-N, NH₄⁺－N and total N contents in leaves, petioles and brown roots, while a significant increase was observed in root-restricted white roots. Moreover, soluble protein contents in petioles, white and brown roots were markedly enhanced under root restriction. The root restriction significantly reduced the GS activities in leaves and petioles, whereas GS activities were higher in root-restricted white and brown roots than the control. The root restriction also induced down regulation of expression of nitrogen metabolism relevant genes (NR, NiR, GS1-1, GS1-2, GS2, Fd-GOGAT, NADH-GOGAT) in leaves and petioles (photosynthetic tissues). However, the transcription levels of all these genes were enhanced in white roots in response to root restriction, especially GS gene in root-restricted white and brown roots. In summary, grapevines might enterprise their NO₃^－ reduction and NH₄⁺assimilation in white roots, in prejudice of the leaves and petioles, in response to root restriction at veraison, leading to less NO₃^－ transported from roots and then assimilated in root-restricted leaves. The inhibition of vegetative growth in ‘Jumeigui’ grapevines under root restriction at veraison is closely associated with the down regulation of gene expression in nitrogen metabolism in leaves and petioles.

Key words: root restriction; grapevine (Vitis vinifera×V. labrusca); nitrogen metabolism; gene expression