For generations, the intricate white stripes adorning the petals of African violets (Saintpaulia ionantha) have captivated enthusiasts, with the phenomenon long attributed to periclinal chimeras. However, groundbreaking research from Japan's Kindai University has pinpointed the SiMYB2 gene as the primary driver of pigment accumulation and the architect behind these distinctive floral patterns, challenging established theories.
The study, published in New Phytologist and led by Professor Munetaka Hosokawa and Dr. Daichi Kurata, reveals that SiMYB2 directly influences anthocyanin levels, the compounds responsible for the violet's vibrant colors. Through meticulous tissue culture experiments, researchers observed that pink petals, possessing higher anthocyanin concentrations, were linked to the expression of SiMYB2-Long in colored tissues. Conversely, white petals, with suppressed anthocyanin production, were associated with SiMYB2-Short found in non-colored areas. This differential expression, influenced by epigenetic factors like DNA methylation, explains the unpredictable pigmentation patterns, particularly those emerging during propagation.
This discovery fundamentally shifts the understanding of African violet coloration, moving away from a purely structural explanation like chimerism towards a sophisticated regulatory mechanism governed by gene expression. The research identified SiMYB2 as the critical gene controlling pigment instability, offering a more precise explanation for the characteristic white-striped patterns.
Professor Hosokawa highlighted the broader implications of this research, noting that while humans have long used mutations for breeding, the underlying genetics of flower patterning is still an evolving field. He anticipates that within the next five to ten years, a deeper understanding of flower genetics, potentially involving the manipulation of genes like SiMYB2, could enable more intentional and precise breeding of patterned flowers, empowering horticulturists to achieve specific color traits with greater efficiency.
The research received support from grants provided by the Sasakawa Scientific Research Grant and the Agricultural Technology and Innovation Research Institute at Kindai University. Kindai University, established in 1949, is recognized for its significant contributions to various scientific disciplines, including horticulture. Professor Hosokawa, a prolific researcher in environmental and agricultural sciences with over 100 published papers, has also served as Chief Editor for Horticultural Research.