Genome-Wide Identification of MYB Transcription Factors and Their Function on Floral Volatile Compounds Biosynthesis in Antirrhinum majus L.

Abstract

The v-MYB avivan myoblastsis virus oncogene homolog (MYB) family is the largest gene family of the transcription factor in plants, involved in plant growth and development, secondary metabolism and resistance to biotic/abiotic stress. Antirrhinum majus (snapdragon) is an ideal material for studying ornamental traits. Nevertheless, there has been no systematic investigation into the AmMYB family of snapdragons. In this study, we identified a total of 162 members of the AmMYB gene family in snapdragons. Gene structure analysis showed that the AmMYB family within the same subgroup had a similar structure and motifs. Analysis of gene duplication events revealed that the amplification of the AmMYB family was driven by whole-genome duplication (WGD) and dispersed duplication. The analysis of cis-acting elements in the promoter region of AmMYB genes reveals a collaborative involvement of light-responsive growth and development elements, stress resistance elements, and hormone-responsive elements jointly participating in the regulation of the AmMYB gene. Collinearity analysis demonstrates significant functional distinctions between AmMYB and monocotyledonous plants. The classification of AmMYB members results in 3 main subgroups with 36 smaller subgroups. All AmMYB genes are distributed across all eight chromosomes, with no apparent correlation between subfamily distribution and chromosome length. Through phylogenetic analysis and RNA-seq analysis, we have identified 9 R2R3-MYB genes that potentially play a role in the regulation of floral volatile organic compounds (FVOCs) biosynthesis. Their expression patterns were verified by qRT-PCR experiments. This study establishes a robust foundation for further investigations into the functionality of AmMYB genes and their molecular mechanisms underlying FVOC biosynthesis in snapdragons.