Abstract

Plants are capable of responding to various environmental stresses by initiating the expression of genes that encode proteins involved in plant growth, fruit ripening, maintaining protein homeostasis, and combating heat stress (HS) by activating heat tolerance systems. The mechanism of resisting against HS is very intricate, and the molecular basis and involvement of the related gene network in Capsicum annuum L. are not fully understood. There are five different heat shock proteins (HSPs) reported in the literature, namely, small HSPs (sHSPs), CaHSP60s, CaHSP70s, CaHSP90s, and CaHSP100s, which play a pivotal role in heat stress response (HSR) in C. annuum. Heat shock factors (HSFs) and heat stress elements (HSEs) govern the transcriptional modifications and control the relative expression of heat shock proteins (HSPs). The heat stress response is the reprogramming of the molecular cascades involving the cell stress responses against the HSR, which is characterized by the increased production of molecular chaperones, which help the plants to counter the negative physiological impacts on proteins, induced by heat and other abiotic stresses. Therefore, understanding the detailed molecular mechanisms of C. annuum in response to extreme temperatures is critical for exploring how they will be affected by climate change and how they behave to cope with these varied climate extremes. This study is focused on providing a complete understanding of the molecular cascades in C. annuum L.’s response to HS, which starts with the sensation of HS signals and activation of the relative molecular cascades that are responsible for the activation of HSFs and initiate their primary targets, e.g., HSPs. Overall, this review provides deep insights into all the cellular responses during HS with a special focus on categorization and physiological aspects of HSPs and HSFs.