Zhao Fengli, Cui Chengqi, Wei Wenxing, Du Zhenwei, Wu Ke, Jiang Xiaolin, Zheng Yongzhan, Liu Yanyang, Mei Hongxian, Zhang Haiyang
Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou, China.
The Shennong Laboratory, Zhengzhou, China.
Theor Appl Genet. 2025 Jan 31;138(2):40. doi: 10.1007/s00122-025-04828-9.
Anthocyanins not only serve as critical pigments determining floral hues but also play essential roles in attracting insects for pollination, feeding animals and mitigating abiotic stress. However, the molecular mechanisms underlying the regulation of flower color in sesame has not yet been reported. In this study, an F population was constructed by crossing 'Ganzhi 9' (purple-flowered) with 'BS377' (white-flowered). Genetic analysis revealed that purple flower is controlled by a single locus named as SiFC (Sesamum indicum flower color). Using the BSA-seq approach, SiFC was preliminarily identified on chromosome 6, which was further mapped to a 473 kb interval using Kompetitive Allele Specific PCR (KASP) marker analysis. Moreover, functional annotation, expression profiling, and sequence analyses confirmed that the SibHLHA (Sesame10992) was the most likely candidate gene for SiFC. In addition, SibHLHA, highly homologous to AtTT8 (a key regulator in the anthocyanin synthesis pathway), was found to interact with WER-like or TTG1 proteins, enhancing anthocyanin accumulation in tobacco leaves. Furthermore, an SNP in the second exon of Sibhlha (BS377 variant) was found to alter the encoding amino acids, which affected Sibhlha binding to MYB protein and showed low anthocyanin in tobacco leaves compared with SibHLHA binding with WER-like or TTG1 proteins. These findings not only deepen our understanding of the molecular mechanisms controlling sesame corolla color, but also provide valuable insights for developing ornamental and consumable sesame varieties.
花青素不仅是决定花色的关键色素，还在吸引昆虫授粉、为动物提供食物以及缓解非生物胁迫方面发挥着重要作用。然而，芝麻花色调控的分子机制尚未见报道。在本研究中，通过将“赣芝9号”（紫色花）与“BS377”（白色花）杂交构建了一个F群体。遗传分析表明，紫色花由一个名为SiFC（芝麻花色）的单基因座控制。利用BSA-seq方法，在6号染色体上初步鉴定出SiFC，并通过竞争性等位基因特异性PCR（KASP）标记分析将其进一步定位到一个473 kb的区间。此外，功能注释、表达谱分析和序列分析证实，SibHLHA（Sesame10992）是SiFC最有可能的候选基因。此外，发现与花青素合成途径中的关键调控因子AtTT8高度同源的SibHLHA与WER-like或TTG1蛋白相互作用，增强了烟草叶片中的花青素积累。此外，发现Sibhlha（BS377变体）第二个外显子中的一个SNP改变了编码的氨基酸，这影响了Sibhlha与MYB蛋白的结合，与SibHLHA与WER-like或TTG1蛋白结合相比，烟草叶片中的花青素含量较低。这些发现不仅加深了我们对芝麻花冠颜色控制分子机制的理解，也为开发观赏性和食用性芝麻品种提供了有价值的见解。
