Wang Zhenyu, Tao Shu, Liu Shaoshuai, Jia Meiling, Cui Dada, Sun Guoliang, Deng Zhongyin, Wang Fang, Kong Xingchen, Fu Mingxue, Che Yuqing, Liao Ruyi, Li Tao, Geng Shuaifeng, Mao Long, Li Aili
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
College of Agriculture, Yangzhou University, Yangzhou, China.
Front Plant Sci. 2022 Apr 13;13:850302. doi: 10.3389/fpls.2022.850302. eCollection 2022.
Optimal spike architecture provides a favorable structure for grain development and yield improvement. However, the number of genes cloned to underlie wheat spike architecture is extremely limited. Here, we obtained a wheat dense spike mutant () induced by Co treatment of a common wheat landrace Huangfangzhu that exhibited significantly reduced spike and grain lengths. The shortened spike length was caused by longitudinal reduction in number and length of rachis cells. We adopted a multi-omics approach to identify the genomic locus underlying the mutant. We performed Exome Capture Sequencing (ECS) and identified two large deletion segments, named 6BL.1 at 334.8∼424.3 Mb and 6BL.2, 579.4∼717.8 Mb in the mutant. RNA-seq analysis confirmed that genes located in these regions lost their RNA expression. We then found that the 6BL.2 locus was overlapping with a known spike length QTL, qSL6B.2. Totally, 499 genes were located within the deleted region and two of them were found to be positively correlated with long spike accessions but not the ones with short spike. One of them, , a well-matched homolog of the rice gene that works in the Brassinosteroids (BR) pathway, was identified to be involved in cell size and number regulation. Further transcriptome analysis of young spikes showed that hormone-related genes were enriched among differentially expressed genes, supporting as a candidate gene. Our work provides a strategy to rapid locate genetic loci with large genomic lesions in wheat and useful resources for future wheat study.
最佳的穗型结构为籽粒发育和产量提高提供了有利的结构。然而，已克隆的控制小麦穗型结构的基因数量极其有限。在这里，我们通过对普通小麦地方品种黄方柱进行钴处理，获得了一个小麦密穗突变体（），该突变体的穗长和粒长显著缩短。穗长缩短是由于穗轴细胞数量和长度的纵向减少所致。我们采用多组学方法来鉴定该突变体潜在的基因组位点。我们进行了外显子捕获测序（ECS），并在该突变体中鉴定出两个大的缺失片段，分别命名为位于334.8∼424.3 Mb的6BL.1和位于579.4∼717.8 Mb的6BL.2。RNA测序分析证实位于这些区域的基因失去了RNA表达。然后我们发现6BL.2位点与一个已知的穗长QTL，qSL6B.2重叠。总共有499个基因位于缺失区域，其中两个基因被发现与长穗材料呈正相关，而与短穗材料不相关。其中一个基因，，是水稻基因的一个匹配良好的同源基因，该水稻基因在油菜素内酯（BR）途径中起作用，被鉴定为参与细胞大小和数量的调控。对幼穗的进一步转录组分析表明，激素相关基因在差异表达基因中富集，支持作为候选基因。我们的工作提供了一种在小麦中快速定位具有大基因组损伤的遗传位点的策略，以及为未来小麦研究提供了有用的资源。
