新型小麦贮藏蛋白TaALPb-7A等位基因的功能解析

Avenin-like b (TaALPb) protein, as a novel wheat storage protein, plays an important role in the improvement of wheat quality. Previously, three alleles were found on chromosome 7A. These two active alleles of TaALPb-7A1, TaALPb-7A2 showed significant positive effects on wheat processing quality. According to these two types of alleles, RNAi vector and two stable RIL populations which deriving from the Jimai44×Jimai229 and YITPI×Jimai229 crosses were constructed, respectively. Meanwhile, wheat transgenic lines of over-expression were obtained. In the present study, the quality and yield traits of positive transgenic lines of over-expression and RNAi were determined on multi- sites by the positive and reverse genetics technology. The effect of these two alleles to wheat processing quality and yield will be further explained in vivo of transgenic wheat. Meanwhile, functional markers will be developed according to the TaALPb-7A1 and TaALPb-7A2 alleles sequence differences. The contribution of wheat processing quality and the markers validity of these two alleles will be reasonably analyzed on multiple years and sites using the two RIL populations. The results will provide convenient molecular markers and theoretical basis for future wheat quality improvement.

Avenin-like b蛋白（TaALPb）是一种新发现的小麦贮藏蛋白，对加工品质有重要作用。本项目前期对小麦TaALPb基因进行研究，发现在7A染色体上有3种等位基因，其中TaALPb-7A1和TaALPb-7A2可正常表达，初步证明其对小麦加工品质有正向效应。针对这两种可正常表达的等位变异类型，已构建济麦44×济麦229、YITPI×济麦229稳定的RIL群体和RNAi表达载体，并获得过表达的小麦转基因株系。在此基础上，本项目拟利用正、反向遗传学，对TaALPb-7A1、TaALPb-7A2基因过表达和RNAi的阳性转基因株系进行多点品质和产量性状测定，在体内水平上进一步明晰2种等位基因对品质和产量的作用；同时根据2种等位基因序列差异，开发功能标记，并利用所构建的RIL遗传群体，多年多点分析其对小麦加工品质的效应和验证标记的有效性，为小麦品质遗传改良提供可用的分子标记和理论依据。

Avenin-like b蛋白（TaALPb）是一种新发现的小麦贮藏蛋白，对加工品质有重要作用。本项目前期对小麦TaALPb基因进行研究，发现在7A染色体上有3种等位基因，其中TaALPb-7A1和TaALPb-7A2可正常表达，初步证明其对小麦加工品质有正向效应。在此基础上，本项目体外掺粉试验表明这2类可表达的基因对揉混特性具有正向作用；构建了这2个可正常表达基因的过表达和RNAi载体，农杆菌介导法获得小麦阳性转基因植株，将稳定植株2021和2022年度种植于山东、北京和山西3地，对其品质和产量相关性状进行分析，结果表明2个基因在过表达株系中对蛋白含量、面筋指数、沉降值、吸水率和UPP等具有正向促进作用，在RNAi沉默株系中具有负向作用。在产量要素方面，过表达后产量减低、株高增加，沉默后产量增加、株高降低，差异不显著。表明该基因对面团品质虽具有一定促进作用，由于对产量的影响，未能在小麦品质遗传改良上大面积应用，需在后续研究中进行进一步研究。开发TaALPb-7A1和TaALPb-7A2功能标记，建立量质协同提高的强筋小麦育种技术。