Chinese Journal OF Rice Science ›› 2015, Vol. 29 ›› Issue (1): 73-81.DOI: 10.3969/j.issn.1001-7216.2015.01.009

• Orginal Article • Previous Articles     Next Articles

Activities of Several Starch Synthesis Enzymes in Filling Grains for Rice Sugary Endosperm Mutant (Sug-11)and Its Relation to Starch Quality

Hua ZHAO1,3, Jun-min WANG2, Qi-fang ZHANG3, Qian ZHAO3, Shu-fang MEI1, Xiang-lei LIU1, Fang-min CHENG3,*()   

  1. 1Jinhua Polytechnic, Jinhua 321017, China
    2Zhejiang Academy of Agricultural Sciences, Hangzhou 310031, China
    3College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
  • Received:2014-08-27 Revised:2014-11-03 Online:2015-01-10 Published:2015-01-10
  • Contact: Fang-min CHENG

水稻糖质胚乳突变体Sug-11籽粒灌浆过程的淀粉合成关键酶活性及其与淀粉理化特性关系

赵华1,3, 王俊敏2, 张其芳3, 赵倩3, 梅淑芳1, 刘向蕾1, 程方民3,*()   

  1. 1金华职业技术学院, 浙江 金华 321017
    2浙江省农业科学院 作物与核技术研究所, 杭州 310031
    3浙江大学 农业与生物技术学院, 杭州 310058
  • 通讯作者: 程方民
  • 基金资助:
    国家自然科学基金资助项目(31271655);浙江省公益性技术应用研究项目(2012C22035)

Abstract:

With the rice sugary endosperm mutant (Sug-11) and its wild-type (Zhonghua 11) as materials, the total soluble sugar, sucrose contents, starch accumulation in filling grains and the starch physicochemical properties were compared to further reveal the temporal patterns of sugar content, several key enzymes activities and their isoform genes transcriptional expression level during the grain filling so as to analyze the physiological mechanism for Sug-11 whose sugars contents change and 1000-grain weight decline from the point of starch biosynthesis pathway in rice grains. The result showed that the differences in soluble sugar and sucrose contents between Sug-11 and its wild-type were not obvious at the initial stage of grain filling, but with the filling process it gradually became apparent. Secondly, the amylose(Am) content and BV(Am) of Sug-11 were significantly decreased while the starch solubility and BV(amylopectin, Ap) were increased compared with Zhonghua 11, indicating that the physicochemical properties of grain starch were significantly affected in the sugary endosperm mutant. Finally, among the key enzymes in starch synthetic metabolism, debranching enzyme(DBE), existed in Sug-11 seeds, were quite different from its wild type in activity and dynamic in the process of grain filling, and PUL transcriptional expression level and DBE activity strikingly decreased at the middle-late stage, resulting in the declined starch accumulation and increased sugar content in Sug-11. However the poor filling and 1000-grain weight decline were, to some extent, associated with dropped ADPGase activity at the early grain filling stage.

Key words: rice, sugary endosperm mutant, starch synthesis, enzymatic activity, starch quality

摘要:

以水稻糖质胚乳突变体Sug-11与其野生型对照中花11为材料,通过对两者籽粒中可溶性总糖、蔗糖含量和淀粉含量以及有关淀粉品质理化指标的比较,结合籽粒灌浆过程中糖类物质含量、淀粉合成代谢关键酶活性和相关同工型基因转录表达水平的动态测定,从籽粒淀粉合成代谢角度,对水稻糖质突变体Sug-11的籽粒糖类含量变化和千粒重下降的生理原因进行了分析。结果表明,Sug-11糖质突变体与其野生型在灌浆初期的可溶性糖和蔗糖含量差异并不明显,随着籽粒灌浆进程,两者间的籽粒糖分含量差异在灌浆中后期逐步趋于明显;与野生型相比,Sug-11糖质胚乳突变体的稻米直链淀粉含量和直链淀粉碘蓝值显著下降,而淀粉溶解度和支链淀粉碘蓝值则显著升高,糖质胚乳突变对稻米淀粉的理化特性也产生了明显的影响;在籽粒淀粉合成代谢的几个关键酶中,Sug-11糖质突变体籽粒中的DBE活性及其在灌浆过程中的动态变化与其野生型存在明显差异,揭示了胚乳糖质突变体Sug-11籽粒中淀粉积累减少、糖分含量增加主要是由籽粒灌浆中后期的PUL转录表达水平和DBE活性的大幅下降所引起的,而Sug-11的籽粒灌浆不良和千粒重下降等现象,则与其ADPGase活性在籽粒灌浆前期的显著下降存在一定的联系。

关键词: 水稻, 糖质突变, 淀粉合成, 酶活性, 淀粉品质

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