MYB19LONG is involved in brushmark pattern development in Asiatic hybrid lily (Lilium spp.) flowers

作者：Masumi Yamagishi

来源：Scientia Horticulturae, 2020, 272: 109570.

DOI：10.1016/j.scienta.2020.109570

• Anthocyanins
• Flower color patterns
• MYB19SHORT
• R2R3-MYB
• Raised spots
• Transcription factor

Asiatic hybrid lily (Lilium spp.) cultivars ‘Centerfold’ and ‘Loreto’ developed an anthocyanin brushmark color pattern on the interior surfaces of flower tepals, which consisted of a set of streaks generated along the main vascular bundles. To clarify the mechanism underlying the brushmark pattern, R2R3-MYB transcription factors that positively regulated anthocyanin biosynthesis were screened in the two cultivars, and MYB19LONG (MYB19L) and MYB19SHORT (MYB19S) were identified. Among them, the expression profile of MYB19L correlated well with those of anthocyanin biosynthesis genes and pigment deposition in tepals. As MYB19L and MYB19S were recently identified as transcription factors regulating the pigmentation of raised spots on lily tepals, the correlation of MYB19L with brushmark and raised spot color patterns was evaluated using F1 populations by segregating the color patterns. MYB19L was always expressed in the F1 plants that developed brushmarks, indicating that MYB19L is necessary for brushmark pigmentation. The F1 plants that developed only raised spots expressed MYB19L, MYB19S, or both, suggesting that MYB19L is also involved in raised spot pigmentation. Segregation of the F1 populations showed that MYB19L was necessary but other gene(s) also participated in brushmark development. Finally, the roles of MYB19L in the development of brushmarks and raised spots are discussed.