Whole-genome analysis of , , gene families in five Rosaceae species and their expression analysis in .

Cystathionine γ-synthase (), S-adenosyl-L-homocysteine hydrolase (), and S-adenosy-L-methionine synthetase () play an important role in the regulation of plant growth, development, and secondary metabolism. In this study, a total of 6 , 6 , and 28 genes were identified from five Rosaceae species (, , , , and ). The evolutionary relationship and microsynteny analysis in five Rosaceae species revealed that duplicated regions were conserved between three gene families (, , ). Moreover, the chromosomal locations, gene structures, conserved motifs, -elements, physicochemical properties, and Ka/Ks analysis were performed by using numerous bioinformatics tools. The expression of different organs showed that the , and genes of pear have relatively high expression patterns in flowers and stems, except for . RNA-seq and qRT-PCR combined analysis showed that may be involved in the regulation of pear stone cell development. In summary, this study provides the basic information of , and genes in five Rosaceae species, further revealing the expression patterns in the pear fruit, which provides the theoretical basis for the regulation of pear stone cells.