Multi-omics reveals RpMYB113-regulated specific anthocyanin accumulation in petal spots of Rosa persica

Area of Science:

• Plant genetics
• Molecular biology
• Biochemistry

Background:

• Rosa persica exhibits distinctive petal spots due to anthocyanin accumulation.
• The genetic regulation of this specific pigmentation pattern is not well understood.

Purpose of the Study:

• To elucidate the molecular mechanisms controlling anthocyanin patterning in Rosa persica petal spots.
• To identify key genetic regulators responsible for the formation of red spots.

Main Methods:

• Microscopic and metabolomic analyses to characterize pigment distribution.
• Identification and functional validation of R2R3-MYB transcription factors.
• Yeast one-hybrid (Y1H) assays to determine DNA-protein interactions.
• Population genetic analysis to assess evolutionary selection.

Main Results:

• Three cyanidin derivatives (Cy3G5G, Cy3G, Cy3R) were found exclusively in the upper epidermis of spot regions.
• RpMYB113, an R2R3-MYB transcription factor, was identified as a key regulator.
• Overexpression of RpMYB113 induced significant anthocyanin production in heterologous systems (Nicotiana tabacum).
• RpMYB113 directly binds to the RpDFR promoter, indicating RpDFR as a direct target gene.
• RpMYB113 and its Hap4 haplotype represent a selected genetic unit driving the spotted phenotype across different genetic backgrounds.

Conclusions:

• RpMYB113 plays a critical role in regulating anthocyanin accumulation in Rosa persica petal spots.
• This study provides mechanistic insights into petal spot formation.
• RpMYB113 is a potential target for molecular breeding of spotted Rosa cultivars.