The MethioninesulfoxidereductaseB2(MsrB2) gene catalyzes the reduction of free and protein-bound methionine sulfoxide to methionine and is known to provide tolerance to biotic and abiotic environmental stresses. There have yet to be any reports that MsrB2 enhances drought tolerance. Two drought-tolerant transgenic rice lines, L-8 (single copy) and L-23 (two copy), expressing the Capsicum annuum MsrB2 (CaMsrB2) gene were selected for stress tolerance phenotyping under drought stress conditions. CaMsrB2 enhanced relative water content (RWC), maintained substantial quantum yield (Fv/Fm ratio), and subsequently improved photosynthetic pigments. Interestingly, L-23, carrying two-copy T-DNA insertion, showed greater drought tolerance through more effective stomatal regulation, carotenoid concentration, and osmotic potential than the wild type. High-tech infrared technology (FLIR SC620) was used for the selection of stress-tolerant physiotypes. Later, the IR results were correlated with other tested physiological parameters. The IR images, average plant temperature, and physiological parameters of the treated plants were discussed in detail.

Transgenic potatoes expressing glyceraldehyde-3-phosphate dehydrogenase (GPD), isolated from the oyster mushroom, Pleurotus sajor-caju, had increased tolerance to salt stress (Jeong et al. 2001). To examine the physiological mechanisms enhancing salt tolerance in GPD transgenic rice plants, the salt tolerance of five GPD transgenic rice lines (T1–T5) derived from Dongjin rice cultivar was tested in a fixed 150-mM saline environment in comparison to two known wild-type rice cultivars, Dongjin (salt sensitive) and Pokali (salt tolerant). Transgenic lines T2, T3, and T5 showed a substantial increase in biomass and relative water content compared to Dongjin. Stomatal conductance and osmotic potential were higher in the GPD transgenic lines and were similar to those in Pokali. The results are discussed based on the comparative physiological response of GPD transgenic lines with those of the salt-sensitive and salt-tolerant rice cultivars.

Drought and salinity are the major abiotic stresses which are being continued to hamper the ecosystem and agriculture of the affected region. Plant species have adaptations to enhance their ability to tolerate stresses through physiological adjustment. Therefore, substantial amount of research are ongoing to provide insights about those mechanisms which enlighten the stress tolerance in plant. In this study, several rice cultivars were collected from the different parts of the world and ion accumulation experiments were conducted to select the best stress tolerant cultivar in drought and salt stress environment. For stress treatment, five rice cultivars were subjected to salt (200 mM NaCl) and drought (200 mM Mannitol) for 72h. Later Na+, Ca++, K+ concentrations in shoot and root samples were examined at different time interval. In both drought and salt stress, rice cultivar C201 (collected for uzbekistan) showed the lowest levels of Na+ ion and Na+: K+ ratio compared to other cultivars. It was significant parallel observation with pokkali (known salt tolerant cultivar). In this preliminary study, it was observed the C201 had more stress tolerant in terms of ion accumulation; however detail physiological studies are required to strengthen the idea regarding the best stress tolerant physiotype.