Molecular evolution and diversity of small heat shock proteins genes in plants

Small heat shock proteins (sHSPs) are the most abundant proteins and considered as Cinderella of molecular chaperon world. The present study is to understand the evolutionary process that led to the diversification of sHSPs specific to plants because of dramatic daily fluctuation in the temperature and other environmental factors which may prompt more efficient chaperon activity of sHSPs. For this purpose mRNA and protein sequences of 62 different plant sHSPs was mined from different databases and analyzed with Clustal W and MEGA 5 Beta # 7 software. Two Neighbor Joining (NJ) and two Dendrogram large congruent trees were obtained from the phylogenetic analysis of mRNA and amino acids. These analyses reveal that sHSPs encoded by one gene family are similar to each other even in different plant species. However, sHSPs belonging to different gene families show very low sequence similarity even in same plant species. These analyses also suggest that gene duplication and mutation play an important role in the evolution and diversification of sHSP.