Role of Thiourea in Mitigating Different Environmental Stresses in Plants

Thiourea (TU), a sulfhydryl compound, chemically known as thiocarbamide, is being increasingly explored as an important bioregulator for growth and development of crop plants. Exogenous application of TU boosts growth and productivity of plants under normal as well as stressful conditions. Earlier researches have proved positive effects of exogenous application of TU as a priming agent for seed pretreatment, as foliar spray, and also as a medium supplement for a wide range of crop species. The application of TU has been found to improve plants' tolerance against several environmental stresses such as salinity, heat, heavy metals, and drought in different plants. The mechanisms of stress ameliorative effects of TU at different growth stages right from seed germination to reproductive maturity have been studied at physiological, biochemical, and molecular levels. The maintenance of proper redox equilibrium within cellular environment is considered to be the basic mechanism behind the action of TU. At present, research efforts are being made to develop TU application into a sustainable, cost-effective, and feasible solution to avoid crop losses at farmers' fields in several stressed environments and to improve yield potential of crop plants. The development of such a low-cost technology is well in time considering the climate change scenario at the global level. The present chapter reviews the mechanistic role of TU on growth stimulation and amelioration of different environmental stresses in crop plants.