Fine mapping and candidate gene analysis of qSRC3 controlling the silk color in maize (Zea mays L.)

In this study, a F2 population arising from the hybridization of the single-segment substitution line qSRC3MT1 with red silk, carrying an introgressed allele from teosinte (Zea mays ssp. mexicana), and the recurrent maize inbred line Mo17, characterized by light green silk, was utilized for fine mapping. We found that the red silk trait is controlled by a semi-dominant genetic locus known as qSRC3, and its expression is susceptible to light-mediated inhibition. Moreover, qSRC3 explained 68.78% of the phenotypic variance and was delimited to a 133.2 kb region, which includes three genes. Subsequent expression analyses revealed that ZmMYB20 (Zm00001d039700), which encodes an R2R3-MYB transcription factor, was the key candidate gene within qSRC3. Yeast one-hybrid and dual-luciferase reporter assays provided evidence that ZmMYB20 suppresses the expression of two crucial anthocyanin biosynthesis genes, namely ZmF3H and ZmUFGT, by directly binding to their respective promoter regions. Our findings underscore the significance of light-inhibited ZmMYB20 in orchestrating the spatial and temporal regulation of anthocyanin biosynthesis. These results advance the production of colorless silk in fresh corn, responding to the misconception that fresh corn with withered colored silk is not fresh and providing valuable genetic resources for the improvement of sweet and waxy maize.PMID:38555318 | DOI:10.1007/s00122-024-04598-w

Source: TAG. Theoretical and Applied Genetics - March 30, 2024 Category: Genetics & Stem Cells Authors: Xueying Wang Yang Zhou Chong You Jinchang Yang Zhengjie Chen Dengguo Tang Jixing Ni Peng Li Le Wang Kaili Zhu Wujiao Deng Haimei Wu Ruifan Bao Zhiqin Liu Pengxu Meng Sijia Yang Tingzhao Rong Jian Liu Source Type: research