The AGAMOUS-LIKE6 (AGL6)-like genes are ancient MADS-box genes and are functionally studied in a few model plants. The knowledge of these genes in wheat remains limited. Here, by studying a ‘double homoeolog mutant’ of the AGL6 gene in tetraploid wheat, we showed that AGL6 was required for the development of all four whorls of floral organs with dosage-dependent effect on floret fertility. Yeast two-hybrid analyses detected interactions of AGL6 with all classes of MADS-box proteins in the ABCDE model for floral organ development. AGL6 was found to interact with several additional proteins, including the G protein β and γ (DEP1) subunits. Analysis of the DEP1-B mutant showed a significant reduction in spikelet number per spike in tetraploid wheat, while overexpression of AGL6 in common wheat increased the spikelet number per spike and hence the grain number per spike. RNA-seq analysis identified the regulation of several meristem activity genes by AGL6, such as FUL2 and TaMADS55. Our work therefore extensively updated the wheat ABCDE model and proposed an alternative approach to improve wheat grain yield by manipulating the AGL6 gene.

中文翻译：

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小麦 AGL6 样 MADS-box 基因是花器官特性的主要调节因子和小穗分生组织发育操作的靶标

AGAMOUS -LIKE6 ( AGL6 ) 样基因是古老的 MADS-box 基因，在一些模式植物中进行了功能研究。对小麦中这些基因的了解仍然有限。在这里，通过研究四倍体小麦中AGL6基因的“双同源突变体” ，我们发现AGL6是所有四个花器官发育所必需的，并且对小花生育力具有剂量依赖性影响。酵母双杂交分析在花器官发育的 ABCDE 模型中检测到 AGL6 与所有类别的 MADS-box 蛋白的相互作用。发现 AGL6 与其他几种蛋白质相互作用，包括 G 蛋白 β 和 γ (DEP1) 亚基。DEP1-B的分析突变体显示四倍体小麦中每穗的小穗数显着减少，而普通小麦中AGL6的过表达增加了每穗的小穗数，从而增加了每穗的粒数。RNA-seq 分析确定了 AGL6 对几个分生组织活性基因的调节，例如FUL2和TaMADS55。因此，我们的工作广泛更新了小麦 ABCDE 模型，并提出了一种通过操纵AGL6基因来提高小麦籽粒产量的替代方法。