The role of antioxidant compounds in plant heat tolerance

Abstract

Plants are sessile organisms, therefore cannot move to more favorable environments; consequently, plant growth and developmental processes are affected, often lethally by stress. High temperature or ‘Heat’ stress is known as major environmental stress that limits plant growth, metabolism, and productivity worldwide. Heat stress is often defined as the rise in temperature beyond a threshold level for a period of time sufficient to cause irreversible damage to plant growth and development. The increase of temperature up to a certain level increases plant growth, photosynthesis, respiration and enzyme activity and after that these parameters tend to decline. One of the ways to deal the with adverse effects of heat stress may involve exploring some molecules that have the potential to protect the plants from the harmful effects of heat stress In recent decades exogenous protectant such as osmoprotectants (proline, glycinebetaine, trehalose, etc.), plant hormone (gibberellic acids, jasmonic acids, brassinosterioids, salicylic acid, etc.), signaling molecules (nitric oxide, hydrogen peroxide, etc.), polyamines (spermidine, spermine, putrescine), trace elements (selenium, silicon, etc.) antioxidants (ascorbic acid, thiamine, glutathione, tocopherol, etc.), have been found effective in mitigating the abiotic stress induced damage in plant. Current report showed that several antioxidants compound such as ascorbic acid and thiamine perform positive effect to combat heat stress in plant is dose dependent manner.