Analysis of the functions of TaGW2 homoeologs in wheat grain weight and protein content traits
Analysis of the functions of TaGW2 homoeologs in wheat grain weight and protein content traits
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DOI：
10.1111/tpj.13903
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
Yi Zhang;Da Li;Dingbo Zhang;Xiaoge Zhao;Xuemin Cao;Lingli Dong;Jinxing Liu;Kunling Chen
中科院分区：
文献类型：
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作者：
Yi Zhang;Da Li;Dingbo Zhang;Xiaoge Zhao;Xuemin Cao;Lingli Dong;Jinxing Liu;Kunling Chen
GW2正成为谷类作物籽粒重的关键遗传决定因素；它在普通小麦（Triticum aestivum L.）中有3个同源物（TaGW2-A1、-B1和-D1）。本文通过分析TaGW2缺少一个（B1或D1）、两个（B1和D1）或全部三个（A1、B1和D1）同源基因的基因编辑突变体，对TaGW2-B1和-D1在小麦常见性状中的功能有了一些认识。首先，TaGW2-B1和-D1均通过影响粒宽和粒长来影响千粒重，但TaGW2-B1的作用强于TaGW2-D1。其次，TaGW2同源物之间存在功能相互作用，因为双突变体（缺乏B1和D1）所显示的TGW增加明显大于其单突变体。第三，TaGW2-B1和-D1都能调节发育籽粒外果皮中细胞的数量和长度，其中TaGW2-B1的调节作用更强。最后，TaGW2同源物也会影响籽粒蛋白质含量，该参数在突变体中普遍增加，特别是在缺乏两个或三个同源物的品系中。与这一发现一致的是，两个与小麦最终使用质量相关的参数，面粉蛋白质含量和面筋强度，在突变体中显著提高。总的来说，我们的数据揭示了TaGW2同源基因在普通小麦粒重和蛋白质含量性状的遗传控制中的功能差异和加性相互作用，这可能加速对这一重要基因的进一步研究及其在小麦改良中的应用。
GW2 is emerging as a key genetic determinant of grain weight in cereal crops; it has three homoeologs (TaGW2-A1, -B1 and -D1) in hexaploid common wheat (Triticum aestivum L.). Here, by analyzing the gene editing mutants that lack one (B1 or D1), two (B1 and D1) or all three (A1, B1 and D1) homoeologs of TaGW2, several insights are gained into the functions of TaGW2-B1 and -D1 in common wheat grain traits. First, both TaGW2-B1 and -D1 affect thousand-grain weight (TGW) by influencing grain width and length, but the effect conferred by TaGW2-B1 is stronger than that of TaGW2-D1. Second, there exists functional interaction between TaGW2 homoeologs because the TGW increase shown by a double mutant (lacking B1 and D1) was substantially larger than that of their single mutants. Third, both TaGW2-B1 and -D1 modulate cell number and length in the outer pericarp of developing grains, with TaGW2-B1 being more potent. Finally, TaGW2 homoeologs also affect grain protein content as this parameter was generally increased in the mutants, especially in the lines lacking two or three homoeologs. Consistent with this finding, two wheat end-use quality-related parameters, flour protein content and gluten strength, were considerably elevated in the mutants. Collectively, our data shed light on functional difference between and additive interaction of TaGW2 homoeologs in the genetic control of grain weight and protein content traits in common wheat, which may accelerate further research on this important gene and its application in wheat improvement.