The structure of starch can be manipulated by changing the expression levels of starch branching enzyme llb in rice endosperm
The structure of starch can be manipulated by changing the expression levels of starch branching enzyme llb in rice endosperm
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DOI：
10.1111/j.1467-7652.2004.00097.x
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发表时间：
2004-11-01
影响因子：
13.8
通讯作者：
Nakamura, Y
中科院分区：
文献类型：
--
作者：
Tanaka, N;Fujita, N;Nakamura, Y
当淀粉分支酶IIb（BEIIb）基因被引入BEIIb缺陷突变体时，所得的转基因水稻植物表现出广泛的BEIIb活性，并且其支链淀粉的精细结构显示出相当大的变化，尽管它们的胚乳中具有与野生型相同水平的其他两种BE亚型BEI和BEIIa。淀粉颗粒的特性，例如糊化行为、形态和 X 射线衍射图，也会根据 BEIIb 活性水平发生显着变化，即使 BEIIb 活性水平略低于或高于野生型。 BEIIb的过度表达导致过多的支链水溶性多糖而不是支链淀粉的积累。这些结果表明，调控 BEIIb 活性是生产用于食品和工业应用的新型淀粉的有效策略。
When the starch branching enzyme IIb (BEIIb) gene was introduced into a BEIIb-defective mutant, the resulting transgenic rice plants showed a wide range of BEIIb activity and the fine structure of their amylopectins showed considerable variation despite having the two other BE isoforms, BEI and BEIIa, in their endosperm at the same levels as in the wild-type. The properties of the starch granules, such as their gelatinization behaviour, morphology and X-ray diffraction pattern, also changed dramatically depending on the level of BEIIb activity, even when this was either slightly lower or higher than that of the wild-type. The over-expression of BEIIb resulted in the accumulation of excessive branched, water-soluble polysaccharides instead of amylopectin. These results imply that the manipulation of BEIIb activity is an effective strategy for the generation of novel starches for use in foodstuffs and industrial applications.