The roles of R2R3-MYBs in regulating complex pigmentation patterns in flowers

Abstract

Pigmentation patterns are ubiquitous in nature. Visually striking pigmentation patterns are not only aesthetically appealing, but also crucial to pollinator interaction and plant fitness. The formation of complex floral pigmentation patterns mainly relies on the spatiotemporal expression of R2R3-MYB transcription factors and is often associated with certain floral development programs, such as floral organ identity, symmetry, which likely provide key information to initiate the patterning. For a complex pigmentation pattern to form, at least a pair of activator and inhibitor is required, despite their interaction might vary depending on the system being investigated. The regulation of pigmentation pattern involves multiple molecular mechanisms, such as transcriptional regulation, small RNA, transposon-mediated gene silencing, and methylation of gene body. Identifying these regulators can be facilitated by using single-cell and spatial transcriptomics as well as innovative plant transformation technologies. Moreover, plant organ development and pigmentation patterns are often interdependent, but current methods of describing patterns are static. Therefore, more precise and quantitative measurements are needed to elucidate the developmental mechanisms underlying complex pigmentation patterns in flowers.