Starch granules size distribution in superior and inferior grains of wheat is related to enzyme activities and their gene expressions during grain filling
Starch granules size distribution in superior and inferior grains of wheat is related to enzyme activities and their gene expressions during grain filling
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小麦优劣粒淀粉粒粒径分布与灌浆过程中酶活性及其基因表达有关
DOI：
10.1016/j.jcs.2009.12.002
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发表时间：
2010-03-01
影响因子：
3.8
通讯作者：
Cao, Weixing
中科院分区：
文献类型：
--
作者：
Zhang, Chuanhui;Jiang, Dong;Cao, Weixing
成熟小麦胚乳中含有A、B、C型淀粉粒，各类型淀粉粒具有独特的理化性质，决定了淀粉的品质。研究了灌浆过程中上级和弱势粒淀粉粒大小分布、淀粉酶活性和淀粉合成酶基因表达的动态变化。与弱势粒相比，上级粒的粒重、淀粉、直链淀粉和支链淀粉含量较高。A型、B型和C型淀粉粒的形成分别始于4 ℃、8 ℃和20 ℃，与淀粉合成酶活性和相关基因表达水平的时间变化规律一致。例如，可溶性淀粉酶和颗粒结合淀粉酶（命名为SSS和GBSS）的活性在20 ℃和24 ℃达到峰值。编码淀粉合酶同工型的基因在不同灌浆期表达。此外，SS I在灌浆期普遍表达，SS II和SS III在灌浆前期和中期表达，GBSS I在灌浆中后期表达。此外，淀粉酶活性和淀粉合成酶编码基因表达的时程变化很好地解释了淀粉颗粒大小分布的动态变化。(C)2009爱思唯尔有限公司保留所有权利。
Mature wheat endosperm contains A-, B-, C-type starch granules, and each class has unique physiochemical properties which determine the quality of starch. The dynamics of the starch granule size distribution, activities of starch synthases and expression of starch synthase encoding genes were studied in superior and inferior grains during grain filling. Compared with inferior grains, superior grains showed higher grain weight, contents of starch, amylose and amylopectin. The formation of A-, B-, C-type starch granules initiated at 4, 8, 20 DAF, respectively, and was well consistent with the temporally change patterns of starch synthase activities and relative gene expression levels. For instance, activities of soluble and granule-bound starch synthases (designated SSS and GBSS) peaked at 20 and 24 DAF. Genes encoding isoforms of starch synthases expressed at different grain filling periods. In addition, SS I was generally expressed over the grain filling stage; the SSII and SS III were expressed over the early and mid grain filling stage, and the GBSS I was expressed during the mid to late grain filling stage. In addition, the time-course changes in activities of starch synthases and expression of starch synthase encoding genes explained well the dynamics of the starch granule size distribution. (C) 2009 Elsevier Ltd. All rights reserved.