Plant Heat Shock Protein Families: Essential Machinery for Development and Defense

Being sessile in nature, plants experience stress due to constantly changing environmental conditions such as drought, salt stress, exposure to chemicals along with highly variable temperature (heat and cold) stress in the era of global warming. Heat shock proteins (HSPs) are a group of proteins, which help plants to cope the adverse conditions caused by these stresses. HSPs help to maintain the cellular homeostasis by maintaining the three-dimensional structure of cellular proteins. Apart from homeostasis maintenance during various stress conditions, these molecular chaperons are also involved in maintaining the normal cellular processes such as protein folding/unfolding, multi-protein complex assembly, protein sorting and transport to correct locations. Presence of high to low molecular weight HSP classes in plant genome points towards a precisely evolved adaptation mechanism. These classes include HSP100, HSP90, HSP70, HSP60, and sHSPs. Here, we have discussed the various classes of HSP proteins with emphasis on their mechanism of action, their evolution across the plant kingdom along with their role in combating the stress.