Antioxidant Defense Mechanisms of Salinity Tolerance in Rice Genotypes

作者：Mohammad Golam Kibria, Mahmud Hossain, Yoshiyuki Murata, Md. Anamul Hoque · 发表于：Rice Science · 年份：2017 · DOI：10.1016/j.rsci.2017.05.001 · 被引用次数：205 · 研究领域：Plant Stress Responses and Tolerance、Aluminum toxicity and tolerance in plants and animals、Rice Cultivation and Yield Improvement

In order to elucidate the role of antioxidant responses in salinity tolerance in rice genotypes under salt stress, experiments were conducted using four rice varieties, including salt-sensitive BRRI dhan 28 and three salt-tolerant varieties BRRI dhan 47, BINA dhan 8 and BINA dhan 10. Thirty-day-old rice seedlings were transplanted into pots. At the active tillering stage (35 d after transplanting), plants were exposed to different salinity levels (0, 20, 40 and 60 mmol/L NaCl). Salt stress caused a significant reduction in growth for all the rice genotypes. Growth reduction was higher in the salt-sensitive genotype than in the salt-tolerant ones, and BINA dhan 10 showed higher salt tolerance in all measured physiological parameters. The reduction in shoot and root biomass was found to be minimal in BINA dhan 10. Chlorophyll content significantly decreased under salt stress except for BINA dhan 10. Proline content significantly increased in salt-tolerant rice genotypes with increased salt concentration, and the highest proline content was obtained from BINA dhan 10 under salt stress. Catalase and ascorbate peroxidase activities significantly decreased in salt-sensitive genotype whereas significantly increased in salt-tolerant ones with increasing salt concentration. However, salt stress significantly decreased guaiacol peroxidase activity in all the rice genotypes irrespective of salt tolerance. K+/Na+ ratio also significantly decreased in shoots and roots of all the rice geno...