《植物生理学报》 2021, 57(3): 703-712

小麦不同灌浆速率品种籽粒淀粉合成与积累研究

刘大同^1,2，蒋正宁^1,2，张晓^1,2，刘健^1,2，杨阳²，周宾寒³，朱冬梅^1,2，高德荣^1,2,3,*

¹江苏里下河地区农业科学研究所, 农业农村部长江中下游小麦生物学与遗传育种重点实验室, 江苏扬州 225007；²扬州大学/江苏省粮食作物现代产业技术协同创新中心, 江苏扬州225009；³长江大学农学院, 湖北荆州434023

通信作者：高德荣；E-mail: gdr@wheat.org.cn

摘　要：

为探明小麦(Triticum aestivum)不同灌浆速率品种籽粒淀粉合成与积累差异的生理基础, 本研究以长江中下游麦区灌浆速率较快的品种‘扬麦16’和‘扬麦23’为材料, 以灌浆速率较慢的‘扬麦15’和‘宁麦13’为对照, 测定不同灌浆时间籽粒中淀粉含量, 通过树脂半薄切片和扫描电镜观察胚乳淀粉体发育特征, 采用荧光定量PCR测定灌浆期籽粒淀粉合成酶基因相对表达量, 并测定淀粉合成关键酶活性。结果表明: ‘扬麦16’和‘扬麦23’灌浆盛期单粒淀粉合成量大于对照, 形态学表现为胚乳细胞内淀粉体大, 充实快, 且B型淀粉体形成早, 淀粉体总体发育进程快。灌浆前中期, ‘扬麦16’和‘扬麦23’中AGPaseI、 GBSSI、 SSSIII、SBEI等4种基因表达量总体高于对照, 并且ADP-葡萄糖焦磷酸化酶(AGPase)、可溶性淀粉合成酶(SSS)、结合态淀粉合成酶(GBSS)和淀粉分支酶(SBE)活性也均高于‘扬麦15’和‘宁麦13’。本研究表明, ‘扬麦16’和‘扬麦23’灌浆期淀粉体较大、淀粉合成关键酶活性高是淀粉合成与积累快的主要原因。

关键词：小麦; 灌浆速率; 淀粉合成; 淀粉体; 基因表达; 关键酶

收稿：2020-08-12   修定：2021-01-18

资助：国家自然科学基金(31700163)、国家重点研发计划(2017YFD0100800)、江苏省重点研发计划(BE2018350)和山东省农业良种工程 项目(2017LZN047)

Studies on starch biosynthesis and accumulation in wheat varieties with different grain-flling rates

LIU Datong^1,2, JIANG Zhengning^1,2, ZHANG Xiao^1,2, LIU Jian^1,2, LIU Jian², ZHOU Binhan³, ZHU Dongmei^1,2, GAO Derong^1,2,3,*

¹Lixiahe Regional Institute of Agricultural Sciences of Jiangsu, Key Laboratory of Wheat Biology and Genetic Breeding in the Middle and Lower Yangtze River, Ministry of Agriculture and Rural Affairs, Yangzhou, Jiangsu 225007, China; ²Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, Jiangsu 225009, China; ³College of Agriculture, Yangtze University, Jingzhou, Hubei 434023, China

Corresponding author: GAO Derong; E-mail: gdr@wheat.org.cn

Abstract:

In order to uncover the differences of starch biosynthesis and accumulation in wheat (Triticum aestivum) varieties with different grain-flling rates, we preformed phenotypic, physiologic and molecular analyses using four wheat varieties of ‘Yangmai16’, ‘Yangmai23’, ‘Yangmai15’ and ‘Ningmai13’. On the basis of analyzation of starch contents during grain flling, the development of starch granule in endosperm cells of caryopsis were observed by semi-thin section method and scanning electron microscopy (SEM). The key enzyme activities of starch biosynthesis and the relative expression of genes were detected. The results show that, compared to the control cultivars of ‘Yangmai15’ and ‘Ningmai13’, the starch contents per grain of ‘Yangmai 16’ and ‘Yangmai 23’ were larger and increased faster. In the endosperm cells of ‘Yangmai16’ and ‘Yangmai23’, the starch granules developed with larger size and faster flling. Meanwhile, the B-type starch granules appeared earlier, which generally indicates a faster developmental process of starch granules. The expression levels of AGPaseI, GBSSI, SSSIII and SBEI were signifcantly higher in the early and middle stages of grain flling. Moreover, the activities of ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS) and starch-branching enzyme (SBE) were also higher in the seeds of ‘Yangmai 16’ and ‘Yangmai 23’. Our results demonstrate that the larger starch granule size and higher activities of starch biosynthetic enzymes during the flling period of  ‘Yangmai 16’ and ‘Yangmai 23’ are mainly responsible for the fast starch biosynthesis and accumulation, as well as the faster grain flling.

Key words: wheat; grain-flling rate; starch biosynthesis; starch granule; gene expression; key enzyme