ABSTRACT
Glutathione is a low molecular weight thiol, present in all living organisms. It is built up from three amino acids: glutamate, cysteine and glycine. The destructive effects of elevated reactive oxygen species levels in plants are controlled by scavenging enzymatic and non-enzymatic mechanisms. Plants are constantly exposed to a wide range of biotic and abiotic stresses such as high salinity, drought, extremes in temperature and heavy metals. When plants experience drought stress, they accumulate abscisic acid in the xylem sap and move to guard cells where the signaling network is activated; that causes shrinking of the guard cells which results in stomatal closure. Salt stress is one of the most detrimental abiotic stresses, and critically damages agricultural crops and causes major reductions in their yield. Plants are photosynthetic organisms that use light energy as an energy source to produce organic materials. In plants, xenobiotics, such as herbicides or insecticides, are converted into intermediates with reduced phytotoxicity by a three-phase process.
