Identification and functional analysis of three new anthocyanin R2R3‐MYB genes in Petunia

• DOI: 10.1002/pld3.114
• Publication Date: 2019-01-21T13:52:57Z
• Authors: Hechen Zhang; Ronald Koes; Hongquan Shang; Zhenzhu Fu; Limin Wang; Xiaoyu Dong; Jing Zhang; Valentina Passeri; Yanbang Li; Hui Jiang; Jie Gao; Yanmin Li; Huijuan Wang; Francesca M. Quat...
• Keywords: Petunia; MYB; Structural gene; WRKY protein domain

We identified three novel members of the R2R3-MYB clade anthocyanin regulators in genome purple flowering Petunia inflata S6 wild accession, and we called them ANTHOCYANIN SYNTHESIS REGULATOR (ASR). Two these genes, ASR1 ASR2, are inactivated by two different single base mutations their coding sequence. All genes absent white species P. axillaris N parodii, red exserta, several hybrida lines, including R27 W115. violacea other lines (M1, V30, W59) instead harbor functional copies ASR genes. Comparative, phylogenic analysis strongly suggest that cluster is a duplication genomic fragment containing with roles pigmentation were previously defined, ANTHOCYANIN4-DEEP PURPLE-PURPLE HAZE (AN4-DPL-PHZ) cluster. An investigation fragments MYBs accessions reveals massive rearrangements have taken place, resulting large differences regions surrounding even closely related species. Yeast two-hybrid assays showed proteins can participate WMBW (WRKY, MYB, B-HLH, WDR) regulatory complex interacting transcription factors AN1 AN11. ASRs induce synthesis when ectopically expressed but appeared to be most effective. The expression patterns ASR2 cover petunia tissues higher at early stages bud development. In contrast, ASR3 only weakly stigma, ovary, anther filaments. characterization MYB completes picture MBW suggests possible mechanisms diversification during plant evolution.