Fig. 3

Identification, phylogenetic and gene structure analysis of lettuce small heat shock protein (LssHsp) gene family. a Phylogenetic relationship of LssHsp proteins and A. thaliana. LssHsp proteins are marked in bold. LssHsp and AtsHsp members in each subfamily (C-I, C-II, C-III, C-IV, C-V, C-VI, ER, MT, CP, and PX) are represented in different colors. Classification of LssHsp genes were assigned according to their molecular weight and subcellular localization (Additional file 1: Table S1). b Gene structure and motif composition analysis of LssHsp genes. Blue boxes, green boxes, and black lines indicate untranslated region (UTR), coding sequence (CDS), and intron, respectively. The numbers on each intron represent the intron phase (0, 1, or 2). Phylogenetic analysis was generated by the Maximum Likelihood method. Numbers at the nodes represent percent of bootstrap values based on 500 replications. Detailed information of all motifs is shown in Additional file 4: Table S4