小麦胚乳Wx蛋白缺失对籽粒淀粉含量的影响

Effects of wheat endosperm Wx protein deficiencies on starch content

旨在通过比较不同的小麦胚乳Wx蛋白亚基缺失类型材料籽粒的Wx蛋白总量支直链淀粉含量及总淀粉含量,明确胚乳Wx蛋白对支直链淀粉合成的作用。利用SDS-PAGE方法鉴定了13个品种Wx蛋白亚基组成,并测定了这些品种的Wx蛋白总量、直、支链淀粉含量及直/支比。结果表明,任何Wx基因缺失都会造成Wx蛋白合成数量的明显著减少,随着Wx基因不表达的数量增多,Wx蛋白合成的减少量增多;糯麦的直链淀粉含量最少。Wx蛋白含量与直链淀粉含量和直/支链淀粉含量之间存在极显著和显著的正相关,r=0.860 0,r=0.810 8;Wx蛋白含量与支链淀粉含量之间呈中度相关,r=0.402 7,这说明Wx蛋白总含量对直链淀粉含量的大小起到决定性作用,而对支链淀粉和总淀粉含量只有一定影响;通过操纵Wx基因可以改变籽粒胚乳中的直链淀粉含量和淀粉的直/支比,进而达到改进淀粉理化特性和加工特性的作用。

To explore the effects of Wx protein content on starch content and composition, an improved SDS-PAGE was used to Indentify Wx protein composition of 13 wheat varieties. The Wx protein content as well as amylase, amylopectin and starch content of the varieties were measured. Results showed that any Wx gene mutation could result in the reduction of amylose content, and with an increase in the number of Wx gene deficiencies, the amylose content decreased. The amylose content of waxy wheat was nearly zero. The correlation coefficient of Wx protein content with amylose was 0.860 0, amylopectin content was 0,402 7, starch content was 0.751 2, and am/ap was 0.810 8, indicating that the Wx protein played a key role in the amylose synthesis. The amylose content can be a good index for the early generation selection of noodle wheat and we can improve the starch property by manipulating the Wx gene.