Fine mapping of CaMYB113 regulating anthocyanin accumulation in pepper cotyledons

Abstract

Cotyledon color can serve as a convenient and efficient morphological marker in F1 hybrid seeds screening, however, few studies on mutants affecting the color of cotyledon have been reported. A genetic population was generated by crossing 21C1344 with purple cotyledon and 21C912 with green cotyledon and the localization of CaMYB113 on chromosome 10 was determined. The results of virus-induced gene silencing (VIGS) demonstrated a substantial decrease in anthocyanin accumulation in cotyledons upon silencing of CaMYB113. The overexpression of the CaMYB113 gene not only resulted in purple pigmentation in both callus and leaves, but also changed the expression levels of downstream genes involved in anthocyanin synthesis. CaMYB113 could bind to crucial genes related to anthocyanin biosynthesis demonstrated by the yeast one-hybrid assay, thereby regulating anthocyanin production and accumulation in capsicum cotyledons. The gene we identified could be converted into a reliable selection marker for achieving stable genetic transformation, while also providing valuable insights for maintaining purity in pepper hybrid seeds.