Fig. 1 Multiple sequence alignment of MLP protein from different species Md:Malus × domestica;At:Arabidopsis thaliana;Pg:Panax ginseng;Op:Papaver somniferum.

Fig. 2 Phylogenetic tree and 22 amino acid residues of MdMLP protein

Fig. 3 Phylogenetic relationships,gene structure,architecture of conserved protein motifs in MLP genes from 5 species Md:Malus × domestica;At:Arabidopsis thaliana;Fv:Fragaria vesca;Vv:Vitis vinifera;RcH:Rosa.

Fig. 4 Synteny analysis of MLP genes between apple and rose,grape,Arabidopsis and strawberry Gray lines in the background indicate the collinear blocks within genomes,while the red lines highlight the syntenic MLP gene pairs.

Fig. 5 Prediction of functional network of interacting proteins of MdMLP Based on Arabidopsis thaliana homologous proteins,String protein database was used to analyze the functional relationship network diagram of MdMLP1-MdMLP13 proteins,including AtMLP28（AT1G70830）,AtMLP31（AT1G70840）,AtMLP34（AT1G70850）,AtMLP43（AT1G70890）,AtMLP328（AT2G01520）and AtMLP423（AT1G24020）.

Fig. 6 Expression levels in different organs of‘Xinjiang 1’of MdMLP in apple The expression of MdMLP in leaves was 1,and the data was calculated based on the 2-??Ct method,and three replicates were set.

Fig. 7 Expression of MdMLP genes in apple cultured under different abiotic stress The expression level of MdMLPs at 0 hour was set as 1,and the data was calculated based on the 2-??Ct method,and three replicates were set. The difference between the same gene and different treatment time was analyzed with a confidence interval of 5%（P < 0.05）.