@Article{phyton.2020.010279, AUTHOR = {Md. Shakhawat Hossain, Md. Daud Hossain, Abdul Hannan, Mirza Hasanuzzaman, Md. Motiar Rohman}, TITLE = {Salt-Induced Changes in Physio-Biochemical and Antioxidant Defense System in Mustard Genotypes}, JOURNAL = {Phyton-International Journal of Experimental Botany}, VOLUME = {89}, YEAR = {2020}, NUMBER = {3}, PAGES = {541--559}, URL = {http://www.techscience.com/phyton/v89n3/39412}, ISSN = {1851-5657}, ABSTRACT = {Salinity stress is a major factor limiting plant growth and productivity of many crops including oilseed. The present study investigated the identification of salt tolerant mustard genotypes and better understanding the mechanism of salinity tolerance. Salt stresses significantly reduced relative water content (RWC), chlorophyll (Chl) content, K+ and K+ /Na+ ratio, photosynthetic rate (PN), transpiration rate (Tr), stomatal conductance (gs), intercellular CO2 concentration (Ci) and increased the levels of proline (Pro) and lipid peroxidation (MDA) contents, Na+ , superoxide (O2•− ) and hydrogen peroxide (H2O2) in both tolerant and sensitive mustard genotypes. The tolerant genotypes maintained higher Pro and lower MDA content than the salt sensitive genotypes under stress condition. The activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) were increased with increasing salinity in salt tolerant genotypes, BJ-1603, BARI Sarisha-11 and BARI Sarisha-16, but the activities were unchanged in salt sensitive genotype, BARI Sarisha-14. Besides, the increment of ascorbate peroxidase (APX) activity was higher in salt sensitive genotype as compared to tolerant ones. However, the activities of glutathione reductase (GR) and glutathione S-transferase (GST) were increased sharply at stress conditions in tolerant genotypes as compared to sensitive genotype. Higher accumulation of Pro along with improved physiological and biochemical parameters as well as reduced oxidative damage by up-regulation of antioxidant defense system are the mechanisms of salt tolerance in selected mustard genotypes, BJ-1603 and BARI Sarisha-16.}, DOI = {10.32604/phyton.2020.010279} }