Analysis Of R2R3-MYB Gene Family In Six Rosaceae Plants And Prediction Of R2R3-MYB-JAZ Interacting In Woodland Strawberry

Many Rosaceae species are economically-important species,and comprise a lot of important fruits and ornamental plants,such as strawberry,apple,pear,peach,Chinese rosa and raspberry.However,the Rosaceae plants often suffer from various stresses such as low temperature,high temperature,drought and disease,which seriously affect the growth and fruit quality of the plants.A number of studies have shown that R2R3-MYB protein could interact with JAZ protein,and play an important role in plant growth,development,metabolic mechanism and responding to biotic and abiotic stress,as well as regulate the expression of related functional genes and enhance plant stress resistance.At present,there are few comparative analysis and evolutionary relationship studies of R2R3-MYB gene family among multiple species.Since the whole-genome sequences of strawberry,apple,Pear,peach,Chinese rosa and raspberry were completed,providing a prerequisite for analysis of the R2R3-MYB gene family.The main research contents and results of this paper are as follows:1.In this study,1221 R2R3-MYB genes were identified from six Rosaceae species(163 in Fragaria vesca,281 in Pyrus communis,285 in Malus domestica,165 in Prunus persica,158 in Rosa Chinese,and 169 in Rubus occidentalis).Phylogenetic analysis showed that the presence of 1221 R2R3-MYB genes in six Rosaceae species,clustered into 73 species-specific duplication clades with 153 genes and 44 lineage-specific duplication clades with 275 genes.R2R3-MYB genes were distributed on all chromosomes of these six Rosaceae species,with a small amount of tandem duplication events.Based on the distribution of Ks,the Ks values in apple and Pear peaked at 0.1 to 0.2;and the peak value of Chinese rose and raspberry Ks was 0.8 to 0.9;in addition,the Ks values in peach peaked at two ranges of 0 to 0.1 and 0.9 to 1.0.Furthermore,most of the R2R3-MYB genes had Ka/Ks values less than 1,indicating that they were driven by purifying selection in evolution.Gene ontology(GO)analysis revealed that R2R3-MYB genes in strawberry and raspberry were more divergent than others.Transcriptome data analysis suggested that the R2R3-MYB genes in strawberry played a key role in growth of fruits.2.13 JAZ genes were identified in woodland strawberry in this research,and predicted 6 pairs of R2R3-MYB-JAZ assumed interacting proteins in woodland strawberry.In addition,the expression data of R2R3-MYB-JAZ interacting protein in different tissues and organs were further analyzed in woodland strawberry,and the Pearson correlation coefficient of each gene pair were calculated respectively.The expression levels of the four pairs of interacting proteins(mrna03712/mrna12541,mrna03712/mrna12975,mrna25149/mrna12541 and mrna25149/mrna12975)were significantly correlated(P<0.01),indicating that the four interacting protein pairs were functionally conserved.