Comparative Genomics Of PRX Gene Family In Brassica

Peroxidases(PRXs)are widely found in various organisms and can be divided into different types according to their structure and function.Among them,Class ? Peroxidases(PRXs),a unique polygene family of plants,are involved in various physiological processes such as auxin metabolism,cell wall extension and thickening,lignin formation and so on.Brassica,a member of the Cruciferous family,includes a variety of important agricultural and horticultural crops.In order to further study the related functions of PRX family in Brassica,this study identified members of PRX gene family in major Brassica crops(Brassica rapa,Brassica oleracea and Brassica nigra)through the whole genome,and carried out bioinformatics analysis on them.The results are as follows:1.A total of 121,119 and 118 PRX genes were identified in Brassica rapa,Brassica oleracea and Brassica nigra,respectively,which were unevenly distributed on chromosomes and multiple pairs of tandem duplicates were found.The number of introns in this family varies,and their relatedness is affected by the genetic structure.2.PRX family genes of Arabidopsis and Brassica were divided into 5 Groups by phylogenetic tree analysis.The number of PRX family genes in different groups was different,indicating that the members of this family had gene loss phenomenon.Collinearity and Ka/Ks analyses showed that there was a high homology between Brassica and Arabidopsis,and most PRX family genes in Brassica were purified and selected during evolution.3.The cis-acting elements of PRX genes were found to be related to hormone response regulation,light response and stress tolerance in Brassica.In addition,transcriptome data showed that BrPRX gene was specific for tissue expression,and some BrPRX genes were down-regulated in male sterility materials.4.Through qRT-PCR analysis,it was found that there were differences in the expression levels of 6 BrPRX genes in the flower buds of sterile materials,which was speculated that this differential gene might be involved in anther development of Brassica rapa.These results laid a foundation for further study of PRX gene function in Brassica.