《植物生理学报》 2018, 54(7): 1195-1204

氮对水稻叶蔗糖磷酸合成酶的影响及其与同化物积累和产量的关系

李国辉¹, 崔克辉^1,2,*

¹作物遗传改良国家重点实验室, 农业部长江中游作物生理生态与耕作重点实验室, 华中农业大学植物科学技术学院, 武汉430070; ²主要粮食作物产业化湖北省协同创新中心, 湖北荆州434025

通信作者：崔克辉；E-mail: cuikehui@mail.hzau.edu.cn

摘　要：

蔗糖磷酸合成酶是植物体内蔗糖合成、碳同化与分配的一个关键调节酶。以3个水稻品种‘两优培九’、‘汕优63’和‘黄华占’为材料, 在低氮和高氮处理下分析了水稻幼穗分化至抽穗不同阶段叶片蔗糖磷酸合成酶(sucrose phosphate synthase, SPS)的基因表达和活性及其与植株同化物积累和产量形成的关系。研究结果表明, 所有SPS基因(OsSPS1、OsSPS2、OsSPS6、OsSPS8和OsSPS11)的相对表达量均随植株生育进程推进而下降; SPS活性的变化趋势与SPS基因表达量一致。与高氮处理相比, 低氮处理下SPS基因的相对表达量和SPS活性增加。相关分析表明, SPS基因的相对表达量和SPS活性均与叶片非结构性碳水化合物(non-structural carbohydrates, NSC)浓度显著正相关, OsSPS1表达和SPS活性状态均与每穗颖花数和籽粒产量显著正相关, OsSPS2、OsSPS6和OsSPS8表达均与结实率和千粒重显著正相关。因此, 适当减少氮肥施用有利于提高SPS基因表达和活性, 进而增加植株NSC积累和促进产量形成。

关键词：水稻; 蔗糖磷酸合成酶; 非结构性碳水化合物; 基因表达; 产量形成

收稿：2018-06-04   修定：2018-07-06

资助：国家自然科学基金(31371548)和国家重点研发计划(2016-YFD0300207)。

The effect of nitrogen on leaf sucrose phosphate synthase and its relationships with assimilate accumulation and yield in rice

LI Guo-Hui¹, CUI Ke-Hui^1,2,*

¹National Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Ecophysiology and Farming System for the Middle Reaches of the Yangtze River, Ministry of Agriculture, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; ²Hubei Collaborative Innovation Center for Grain Industry, Jingzhou, Hubei 434025, China

Corresponding author: CUI Ke-Hui; E-mail: cuikehui@mail.hzau.edu.cn

Abstract:

Sucrose phosphate synthase (SPS) plays a central role in the sucrose production and is one of the key regulatory enzymes in carbon assimilation and partitioning in plants. In current study, three rice cultivars, ‘Liangyoupeijiu’, ‘Shanyou63’ and ‘Huanghuazhan’, were used to investigate relationships among gene expression and activity of SPS, assimilates accumulation, and yield formation under low and high nitrogen application. The results indicated that expressions of leaf SPS genes (OsSPS1, OsSPS2, OsSPS6, OsSPS8 and OsSPS11) decreased at different stages from panicle initiation to heading date. Changes in SPS activities were consistent with that of SPS gene expressions. Low nitrogen application increased SPS gene expressions and SPS activities when compared to high nitrogen application. Correlation analysis showed that the gene expressions and activities of SPS were significantly and positively correlated with leaf non-structural carbohydrates (NSC) concentration, OsSPS1 expression and SPS activation were significantly and positively correlated with spikelets per panicle and grain yield, and expressions of OsSPS2, OsSPS6 and OsSPS8 were significantly and positively correlated with grain filling percentage and grain weight. These results suggested that enhanced expressions and activities of leaf SPS were beneficial to NSC accumulation of plant and yield formation via calculated reductions in nitrogen application rate.

Key words: rice; sucrose phosphate synthase; non-structural carbohydrates; gene expression; yield formation