Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Int J Mol Sci. 2022 Feb 26;23(5):2586. doi: 10.3390/ijms23052586.
Tassel branch number (TBN) is one of the important agronomic traits that contribute to the efficiency of seed production and has been selected strongly during the modern maize breeding process. However, the genetic mechanisms of TBN in maize are not entirely clear. In this study, we used a B73 × CML247 recombination inbred lines (RILs) population to detect quantitative trait loci (QTLs) for TBN. A total of four QTLs (, , , and ) and six candidate genes were identified through expression analysis. Further, one of the candidates (GRMZM2G010011, ) encoding an S-acyltransferase was selected to validate its function by CRISPR-Cas9 technology, and its loss-of-function lines showed a significant increase in TBN. A key SNP(-101) variation in the promoter of was significantly associated with TBN. A total of 17 distant eQTLs associated with the expression of were identified in expression quantitative trait loci (eQTL) analysis, and may be a major factor involved in regulating . These findings of the present study promote our understanding of the genetic basis of tassel architecture and provide new gene resources for maize breeding improvement.
穗枝数（TBN）是影响种子生产效率的重要农艺性状之一，在现代玉米育种过程中受到了强烈的选择。然而，玉米 TBN 的遗传机制尚不完全清楚。在这项研究中，我们利用 B73×CML247 重组自交系（RILs）群体来检测 TBN 的数量性状位点（QTLs）。通过表达分析，共鉴定到四个 QTL（qTBN-1.1、qTBN-1.2、qTBN-7.3 和 qTBN-8.1）和六个候选基因。进一步，选择其中一个候选基因（GRMZM2G010011，）编码 S-酰基转移酶，通过 CRISPR-Cas9 技术验证其功能，其功能丧失系的 TBN 显著增加。在启动子中发现了一个关键的 SNP（-101）变异，与 TBN 显著相关。在表达数量性状位点（eQTL）分析中，共鉴定到与表达相关的 17 个远距离 eQTL，可能是调控的主要因素。本研究的这些发现促进了我们对穗结构遗传基础的理解，并为玉米育种改良提供了新的基因资源。
