外源ABA和6-BA对不同持绿型小麦籽粒灌浆进程及蛋白质含量影响

Effects of Exogenous ABA and 6-BA on Protein Content and Grain Filling Process in Different Types of Stay-Green Wheat

本文旨在揭示持绿型小麦品种的灌浆特性和籽粒蛋白质含量对外源激素的响应，认识植物激素调控籽粒灌浆和蛋白质合成的作用机制。自盛花期开始，连续4d喷施10mgL^-1脱落酸（ABA）和6．苄基腺嘌呤（6-BA），持绿型品种汶农6号的灌浆期（t3）、活跃生长期（D）、平均灌浆速率（Gmean）、最大灌浆速率（Gmax）、千粒重（TGW）和产量（GY）均大于非持绿型济麦20，且强势粒的各项灌浆参数均大于弱势粒。喷施两种外源激素显著提高两品种的Gmean、Gmax、TGW和GY，对t3和D的影响存在粒位及品种效应。喷施ABA和6-BA均显著提高花后35d的籽粒蛋白质含量，显著提高汶农6号强、弱势粒的麦谷蛋白含量，但济麦20强、弱势粒的麦谷蛋白含量显著降低。喷施ABA后，汶农6号强势粒花后7～21d的玉米素核苷（zR）含量显著升高；喷施6-BA后，济麦20弱势粒花后14～35d的ZR含量显著升高，而汶农6号强势粒7～21d的赤霉素（GA3）含量显著降低，弱势粒花后7～28d的GA3含量显著提高。喷施外源ABA和6-BA显著提高两品种强势粒花后7～21d的生长素（IAA）和ABA含量。ABA和6-BA处理显著提高花后7～21d谷氨酰胺合成酶（GS）活性。可见，喷施外源ABA和6-BA使小麦内源激素水平变化，促进籽粒灌浆，增加粒重和产量，提高籽粒GS活性和蛋白质含量，改变蛋白质组分。

This study aimed to understand the grain filling process and protein biosynthesis in grain of stay-green wheat in re- sponse to exogenous hormones. At blooming stage, plants of Wennong 6 （stay-green cultivar） and Jimai 20 （control） were sprayed with 10 mg L^-1 abscisic acid （ABA） and 6-benzyladenine （6-BA） for four days. Compared with Jimai 20, Wermong 6 had longer grain-filling duration （t3） and the active growth phase （D）, higher mean grain-filling rate （Gmean） and maximum grain-filling rate （Gmax）, larger thousand-grain weight （TGW）, and greater grain yield （GY）. All parameters for grain filling were higher in superior grain than in inferior grain. Gmean, Gmax, TGW, and GY were promoted by ABA or 6-BA treatment in both cultivars. However, the effects of exogenous hormones on t3 and D were interacted with grain position in a panicle and genotype. Exogenous ABA and 6-BA treatment obviously increased protein content at 35 days after anthesis （DAA）. The glutenin contents in ABA-treated and 6-BA-treated Wennong 6 significantly increased at 35 DAA; however, those in Jimai 20 decreased at 35 DAA. Exogenous ABA increased endogenous zeatin （ZR） content from 7 DAA to 21 DAA. In Wennong 6, GA3 content in superior grain was significantly decreased from 7 DAA to 21 DAA by 6-BA treatment, however, its content in inferior grain was enhanced. In both cultivars, ap-plication of ABA and 6-BA resulted in significant increases of endogenous auxin （IAA） and ABA contents from 7 DAA to 21 DAA, along with significant enhancement of glutamine synthetase （GS） activity.