Chen Hao, Zhang Xing, Xu Shuhao, Song Chengxiang, Mao Hailiang
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
Front Plant Sci. 2023 Sep 8;14:1229827. doi: 10.3389/fpls.2023.1229827. eCollection 2023.
Wheat is a staple crop for the world's population, and there is constant pressure to improve grain yield, which is largely determined by plant architecture. SQUAMOSA promotor-binding protein-like (SPL) genes have been widely studied in rice, including their effects on plant architecture, grain development, and grain yield. However, the function of homologous genes in wheat has not been well investigated. In this study, and , wheat's closest orthologous of , were functionally investigated using gene-editing assays, revealing that these genes redundantly influence plant height, tiller number, spike length, and thousand-grain weight (TGW). Bract outgrowth was frequently observed in the hexa-mutant, occasionally in the quintuple mutant but never in the wild type. Transcriptome analysis revealed that the expression of many spike development-associated genes was altered in hexa-mutants compared to that in the wild type. In addition, we analyzed the sequence polymorphisms of and among wheat germplasm and found superior haplotypes of and with significantly higher TGW, which had been positively selected during wheat breeding. Accordingly, dCAPS and KASP markers were developed for and , respectively, providing a novel insight for molecular marker-assisted breeding in wheat. Overall, our results highlight the role of in regulating plant architecture and their potential application for wheat grain yield improvement through molecular breeding.
小麦是全球人口的主要粮食作物，提高粮食产量面临着持续的压力，而粮食产量在很大程度上由株型决定。SQUAMOSA启动子结合蛋白样（SPL）基因在水稻中已得到广泛研究，包括它们对株型、籽粒发育和粮食产量的影响。然而，小麦中同源基因的功能尚未得到充分研究。在本研究中，利用基因编辑试验对小麦中与水稻OsSPL14最接近的直系同源基因TaSPL14-A1和TaSPL14-D1的功能进行了研究，结果表明这些基因对株高、分蘖数、穗长和千粒重具有冗余影响。在六突变体中经常观察到颖片生长，在五突变体中偶尔观察到，但在野生型中从未观察到。转录组分析表明，与野生型相比，许多与穗发育相关的基因在六突变体中的表达发生了改变。此外，我们分析了小麦种质中TaSPL14-A1和TaSPL14-D1的序列多态性，发现了千粒重显著更高的TaSPL14-A1和TaSPL14-D1的优良单倍型，这些单倍型在小麦育种过程中受到了正向选择。因此，分别为TaSPL14-A1和TaSPL14-D1开发了dCAPS和KASP标记，为小麦分子标记辅助育种提供了新的见解。总体而言，我们的结果突出了TaSPL14在调节株型方面的作用及其通过分子育种提高小麦籽粒产量的潜在应用价值。
