Underlying mechanisms of exogenous substances involved in alleviating plant heat stress

Abstract

Heat stress (HS) negatively affects the growth, metabolism, reproduction, and productivity of plants and its adversary can be lessened through using exogenous substance (ES). With an extensive and comprehensive review of 136 collective literatures published for last two decades on alleviation of HS in plants through applying 65 ESs, we have proposed and discussed in details six mechanisms that underline their different effects on plant responses and regulations against HS at the structural, biochemical, molecular level through: 1) improving antioxidant pathways in plants; 2) promoting the synthesis of osmotic regulatory substances in cells; 3) enhancing photosynthetic functions in leaves; 4) adjusting the hormone balance, 5) regulating the expression of HS defensive genes and signal transduction; and 6) microbe-involved regulatory processes. More detailed information, research progress, perspectives and potential breakthroughs on using various ESs in alleviating plant HS are outlined to benefit researchers working on the subject to have a more comprehensive understanding of ESs effects and their underlying tolerance against plant HS.

Keywords

• Heat stress
• Exogenous substances
• Heat tolerance
• Physiological regulation