Heat stress is considered to induce a wide range of physiological and biochemical changes that cause severe damage to plant cell membrane, disrupt protein synthesis, and affect the efficiency of photosynthetic system by reducing the transpiration due to stomata closure. A brief and mild heat shock is known to induce acquired thermo tolerance in plants that is associated with concomitant production of heat shock proteins’ (HSPs) gene family including HSP70. The findings from different studies by use of technologies have thrown light on the importance of HSP70 to heat, other abiotic stresses and environmental challenges in desserts. There is clear evidence that under heat stress, HSP70 gene stabilized the membrane structure, chlorophyll and water breakdown. It was also found that under heat stress, HSP70 decreased the malondialdehyde (MDA) content and increased the production of superoxide dismutase (SOD) and peroxidase (POD) in transgenic plants as compared to non-transgenic plants. Some reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radical are also synthesized and accumulated when plants are stressed by heat. Hence HSP70 can confidently be used for transforming a number of heat tolerant crop species.
Part of the book: Advances in Plant Defense Mechanisms
Plants are under the threat of climatic changes and there is a reduction in productivity and deterioration in quality. The application of nanoparticles is one of the recent approaches to improve plant yield and quality traits. A number of nanoparticles, such as zinc nanoparticles (ZnO NPs), iron nanoparticles (Fe2O3 NPs), silicon nanoparticles (SiO2 NPs), cerium nanoparticles (CeO2 NPs), silver nanoparticles (Ag NPs), titanium dioxide nanoparticles (TiO2 NPs), and carbon nanoparticles (C NPs), have been reported in different plant species to play a role to improve the plant physiology and metabolic pathways under environmental stresses. Crop plants readily absorb the nanoparticles through the cellular machinery of different tissues and organs to take part in metabolic and growth processes. Nanoparticles promote the activity of a range of antioxidant enzymes, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), in plant species, which in turn improve the growth and development under stressful conditions. The present review focuses on the mode of action and signaling of nanoparticles to the plant systems and their positive impact on growth, development, and ROS scavenging potential. The appropriate elucidation on mechanisms of nanoparticles in plants leads to better growth and yields under stress conditions, which will ultimately lead to increased agricultural production.
Part of the book: Abiotic Stress in Plants