Systematic Analysis of MYB Family Genes in Potato and Their Multiple Roles in Development and Stress Responses

Abstract

The MYB proteins represent a large family of transcription factors and play important roles in development, senescence, and stress responses in plants. In the current study, 233 MYB transcription factor-encoding genes were identified and analyzed in the potato genome, including 119 R1-MYB, 112 R2R3-MYB, and two R1R2R3-MYB members. R2R3-MYB is the most abundant MYB subclass and potato R2R3-MYB members together with their <i>Arabidopsis</i> homologs were divided into 35 well-supported subgroups as the result of phylogenetic analyses. Analyses on gene structure and protein motif revealed that members from the same subgroup shared similar exon/intron and motif organization, further supporting the results of phylogenetic analyses. Evolution of the potato MYB family was studied via syntenic analysis. Forty-one pairs of <i>StMYB</i> genes were predicted to have arisen from tandem or segmental duplication events, which played important roles in the expansion of the <i>StMYB</i> family. Expression profiling revealed that the <i>StMYB</i> genes were expressed in various tissues and several <i>StMYB</i> genes were identified to be induced by different stress conditions. Notably, <i>StMYB030</i> was found to act as the homolog of <i>AtMYB44</i> and was significantly up-regulated by salt and drought stress treatments. Furthermore, overexpression of <i>StMYB030</i> in <i>Arabidopsis</i> enhanced salt stress tolerance of transgenic plants. The results from this study provided information for further functional analysis and for crop improvements through genetic manipulation of these <i>StMYB</i> genes.