南京农业大学Xiue Wang等研究人员合作揭示调控合成硬粒小麦-簇毛麦异源六倍体谷粒发育的剂量效应基因。该项研究成果于2024年4月25日在线发表在《遗传学与基因组学杂志》上。

研究人员表示，植物多倍体化通常会导致细胞体积和籽粒尺寸增大，这可能受到基因组剂量和转录丰度增加的影响。合成的硬粒小麦（AABB）-簇毛麦（VV） 异源六倍体（AABBVV）比四倍体和二倍体亲本明显增大了籽粒尺寸，尤其是籽粒长度。

为了研究多倍体化如何在转录水平上影响谷粒的发育，研究人员利用硬粒小麦、簇毛麦和两倍体的未成熟种子进行了转录组分析。在剂量效应基因中，来自簇毛麦基因组V的差异表达基因（DEG）的贡献较大。与谷粒发育相关的基因在剂量效应基因中所占比例较高。

有趣的是，春化基因TaVRN1是硬粒小麦-簇毛麦和圆锥小麦-节节麦双倍体的正剂量效应基因之一。TaVRN1同源物的表达水平与谷粒大小和重量呈显著正相关。TaVRN1-B1或TaVRN1-D1突变会导致花期延迟、细胞大小、谷粒大小和谷粒产量下降。这些数据表明，剂量效应基因通过调控谷粒的发育可能是谷粒增大的重要原因之一。剂量效应基因的鉴定和功能验证可能有助于找到提高小麦产量的有价值基因。

附：英文原文

Title: Dosage effect genes modulating grain development in synthesized Triticum durum-Haynaldia villosa allohexaploid

Author: Jingya Yuan a, Xiue Wang a

Issue&Volume: 2024/04/25

Abstract: Polyploidization in plants often leads to increased cell size and grain size, which may be affected by the increased genome dosage and transcription abundance. The synthesized Triticum durum (AABB)-Haynaldia villosa (VV) amphiploid (AABBVV) has significantly increased grain size, especially grain length than the tetraploid and diploid parents. To investigate how the polyploidization affects grain development at transcriptional level, we perform transcriptome analysis using the immature seeds of T. durum, H. villosa, and the amphiploid. The dosage effect genes are contributed more by differentially expressed genes (DEGs) from genome V of H. villosa. The dosage effect genes overrepresent grain development related genes. Interestingly, the vernalization gene TaVRN1 is among the positive dosage effect genes in the T. durumH. villosa and T. turgidumAe. tauschii amphiploids. The expression levels of TaVRN1 homologs are significantly positively correlated with the grain size and weight. The TaVRN1-B1 or TaVRN1-D1 mutation shows delayed florescence, decreased cell size, grain size, and grain yield. These data indicate that dosage effect genes could be one of the important explanations for increased grain size by regulating grain development. The identification and functional validation of dosage effect genes may facilitate the finding of valuable genes for improving wheat yield.

DOI: 10.1016/j.jgg.2024.04.010

Source: https://www.sciencedirect.com/science/article/abs/pii/S167385272400081X