A Rapid, Direct Observation Method to Isolate Mutants with Defects in Starch Grain Morphology in Rice
A Rapid, Direct Observation Method to Isolate Mutants with Defects in Starch Grain Morphology in Rice
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DOI：
10.1093/pcp/pcq040
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发表时间：
2010-05-01
影响因子：
4.9
通讯作者：
Sakamoto, Wataru
中科院分区：
文献类型：
--
作者：
Matsushima, Ryo;Maekawa, Masahiko;Sakamoto, Wataru
淀粉在淀粉体中形成透明颗粒，称为淀粉粒（SG）。尽管淀粉的葡萄糖聚合物组成简单，但SGs根据植物种类的不同表现出不同的形态，特别是在禾本科的胚乳中。这项研究报告了一种无需化学固定或树脂包埋即可制备胚乳薄片的新方法，使我们能够清楚地观察亚细胞 SG。使用这种方法，我们观察了 5,000 个诱变水稻种子的 SG 形态，并能够分离出 SG 形态发生改变的突变体。在名为 ssg（次标准淀粉粒）的五个突变体中，观察到小 SG（ssg1ssg3）数量增加、SG 增大（ssg4）和 SG 内部结构异常（ssg5）。支链淀粉链长分布分析和突变基因的鉴定表明ssg1、ssg2、ssg3与先前分离的直链淀粉延伸(ae)突变体之间可能存在等位关系，而ssg4和ssg5似乎是新的突变体。与传统的观察方法相比，本文开发的方法能够更有效地获得亚细胞SG的精细图像，并且适合大量样本的观察。
Starch forms transparent grains, referred to as starch grains (SGs), in amyloplasts. Despite the simple glucose polymer composition of starch, SGs exhibit different morphologies depending on plant species, especially in the endosperm of the Poaceae family. This study reports a novel method for preparing thin sections of endosperm without chemical fixation or resin embedding that allowed us to visualize subcellular SGs clearly. Using this method, we observed the SG morphologies of 5,000 mutagenized rice seeds and were able to isolate mutants in which SGs were morphologically altered. In five mutants, named ssg (substandard starch grain), increased numbers of small SGs (ssg1ssg3), enlarged SGs (ssg4) and abnormal interior structures of SGs (ssg5) were observed. Amylopectin chain length distribution analysis and identification of the mutated gene suggested a possible allelic relationship between ssg1, ssg2, ssg3 and the previously isolated amylose-extender (ae) mutants, while ssg4 and ssg5 seemed to be novel mutants. Compared with conventional observation methods, the methods developed here are more effective for obtaining fine images of subcellular SGs and are suitable for the observation of a large number of samples.