The use of micro-beam X-ray diffraction for the characterization of starch crystal structure in rice mutant kernels of waxy, amylose extender, and sugary1
The use of micro-beam X-ray diffraction for the characterization of starch crystal structure in rice mutant kernels of waxy, amylose extender, and sugary1
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DOI：
10.1016/j.jcs.2007.08.005
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发表时间：
2008-07-01
影响因子：
3.8
通讯作者：
Kitamura, Shinichi
中科院分区：
文献类型：
--
作者：
Kubo, Akiko;Yuguchi, Yoshiaki;Kitamura, Shinichi
对野生型水稻和突变体的切片进行了微束X射线衍射分析。该方法允许的晶体结构进行分析，较少的细胞破坏和较少的人工影响，发生在从组织中纯化淀粉，并提供有关的本地化和分布在胚乳中的淀粉的晶体结构的信息。携带颗粒结合淀粉合成酶I（GBSSI）基因缺陷的野生型和蜡质突变体的籽粒切片上的淀粉显示A型衍射图案;观察到位于籽粒内部和外部区域的淀粉之间的结晶图案没有差异。蜡质和直链淀粉延伸剂（ae）突变体的双突变体携带的缺陷淀粉分支酶IIb基因积累无直链淀粉的B型淀粉。在异淀粉酶I位点上发生突变的蜡质和糖质双突变体1的籽粒切片在外部区域显示A型衍射图案，并且在内部区域是无定形的。从野生型和突变体的籽粒中的聚葡聚糖的链长分布分析表明，ae支链淀粉有更多的长链和短链比野生型和蜡质支链淀粉。另一方面，糖胚乳内部区域的水溶性多糖比外部区域的支链淀粉具有更多的短链。这些结果表明，支链淀粉中的分支链长度对于决定A型和B型淀粉的形成至关重要。(c)2007爱思唯尔有限公司保留所有权利。
Micro-beam X-ray diffraction analyses were carried out on slices from wild-type rice and mutants. The method permitted the crystalline structure to be analyzed with less destruction of cells and fewer artificial effects that occur during the purification of starch from tissue and provided information concerning the localization and crystalline structure of starches distributed in the endosperm. The starch on kernel slices from the wild-type and waxy mutant, carrying a defect for the Granule-bound starch synthase I (GBSSI) gene, displayed an A-type of diffraction pattern; no difference in the crystalline patterns between starches located in the inner and outer region in a kernel were observed. A double mutant of the waxy and amylose extender (ae) mutant carrying a defect for the Starch branching enzyme IIb gene accumulated amylose-free B-type starches. The kernel slice from the double mutant of waxy and sugary1, mutated on the Isoamylase I locus, displayed an A-type diffraction pattern in the outer region and was amorphous in the inner region. A chain-length distribution analysis of polyglucans in kernels from wild-type and mutants showed that ae amylopectin had more long chains and less short chains than the wild-type and waxy amylopectin. On the other hand, the water-soluble polysaccharide in the inner region of the sugary1 endosperm had more short chains than the amylopectin in the outer region counterparts. These results indicate that branch chain length in amylopectin is crucial in determining the formation of A- and B-type starches. (c) 2007 Elsevier Ltd. All rights reserved.