MYB regulation of GST/GT mediates red petal spot development in cotton
Sujun Zhang,
Jie Chen,
Tao Jiang,
Haitao Wang,
Xiao Cai,
Cunjing Liu,
Liyuan Tang,
Xinghe Li,
Yaqian Sun,
Jianhong Zhang
Affiliations
Sujun Zhang
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Jie Chen
Yazhouwan National Laboratory, Sanya 572024, Hainan, China
Tao Jiang
Institute of Cash Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, Hebei, China
Haitao Wang
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Xiao Cai
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Cunjing Liu
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Liyuan Tang
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Xinghe Li
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China
Yaqian Sun
Institute of Cash Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, Hebei, China
Jianhong Zhang
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, Shijiazhuang 050051, Hebei, China; Corresponding author.
Red petal spots are beneficial for attracting cotton pollinators and producing hybrid seeds, and the anthocyanin pathway is generally regarded as a metabolic cause of petal coloration. The current study identified an MYB-encoding gene (Gar07G09390, GaMYB) as a candidate gene involved in cotton coloration by map-based cloning, and this MYB could positively regulate a candidate glutathione S‑transferase gene (Gar07G08900, GaGST). To unveil potentially involved genes within the GaMYB-regulating-GaGST route, color metabolites of both GaMYB- and GaGST-virus-induced gene silencing (VIGS) petals were investigated, revealing that they were largely glycosyl-decorated flavonoids. Accordingly, a transcriptomic survey of both VIGS petals identified a glycosyl-transferase gene (GaGT, Gar02G15390). Notably, this GaGT is adjacent to one of the genome-wide association study loci concerning petal spots in Gossypium arboreum, and it is also positively regulated by GaMYB. This new regulatory route including both GST and GT regulated by MYB is conserved among the three cotton species examined in this study (Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense). Accordingly, comprehensively evaluating the influence of these candidates and their homologs on cotton coloration may provide a more in-depth understanding of cotton coloration, ultimately facilitating the breeding of more colorful cotton.
