Genome-Wide Identification of R2R3-MYB Gene Family in Strawberry (Fragaria vesca L.) and Functional Characterization of FvMYB103 in Cold Stress

TL;DR

This study identifies 106 R2R3-MYB genes in strawberries and shows that FvMYB103 improves cold tolerance when overexpressed in Arabidopsis.

Contribution

The study provides the first genome-wide analysis of R2R3-MYB genes in Fragaria vesca and functionally characterizes FvMYB103 in cold stress.

Findings

106 R2R3-MYB genes were identified and classified into 25 subfamilies in Fragaria vesca.

FvMYB103 overexpression in Arabidopsis increased cold tolerance and improved physiological indices.

Gene duplication and promoter elements suggest roles in stress and hormone responses.

Abstract

Fragaria vesca L., a widely distributed model species, serves as a key resource for studying the evolution and genetics of the Fragaria genus. Research has shown that R2R3-MYB transcription factors are crucial for plant growth and development. However, their specific role in cold resistance in F. vesca is not well understood. In this study, we used the latest genome data for the strawberry (F. vesca v6.0). We performed a genome-wide identification of the R2R3-MYB gene family in F. vesca. We identified a total of 106 R2R3-FvMYBs. Based on their predicted functions in plants, we classified these genes into 25 distinct subfamilies. We then conducted a comprehensive bioinformatics analysis of this family. We performed a detailed examination of the R2R3-FvMYBs structures and physicochemical properties. This analysis provided five key parameters for each protein: molecular weight, the number of amino acids, theoretical isoelectric point, grand average of hydropathicity (GRAVY), and instability index. Gene duplication analysis suggested that segmental duplications were a primary driver of the proliferation of this gene family. Promoter cis-acting element prediction revealed that a large proportion of R2R3-FvMYBs possess elements predominantly associated with phytohormone responsiveness and biotic/abiotic stress responses. Quantitative real-time reverse transcription PCR (qRT-PCR) results confirmed that the expression levels of several R2R3-FvMYBs were upregulated under cold stress. Furthermore, compared to wild-type controls, the overexpression of FvMYB103 in Arabidopsis thaliana enhanced cold tolerance, accompanied by increases in the relevant physiological indices. Collectively, these findings support further investigation into R2R3-MYB gene family to directly assess their contribution to cold resistance.

Figures