Kumar, V.; Srivastava, A.K.; Sharma, D.; Pandey, S.P.; Pandey, M.; Dudwadkar, A.; Parab, H.J.; Suprasanna, P.; Das, B.K. Antioxidant Defense and Ionic Homeostasis Govern Stage-Specific Response of Salinity Stress in Contrasting Rice Varieties. Plants2024, 13, 778.
Kumar, V.; Srivastava, A.K.; Sharma, D.; Pandey, S.P.; Pandey, M.; Dudwadkar, A.; Parab, H.J.; Suprasanna, P.; Das, B.K. Antioxidant Defense and Ionic Homeostasis Govern Stage-Specific Response of Salinity Stress in Contrasting Rice Varieties. Plants 2024, 13, 778.
Kumar, V.; Srivastava, A.K.; Sharma, D.; Pandey, S.P.; Pandey, M.; Dudwadkar, A.; Parab, H.J.; Suprasanna, P.; Das, B.K. Antioxidant Defense and Ionic Homeostasis Govern Stage-Specific Response of Salinity Stress in Contrasting Rice Varieties. Plants2024, 13, 778.
Kumar, V.; Srivastava, A.K.; Sharma, D.; Pandey, S.P.; Pandey, M.; Dudwadkar, A.; Parab, H.J.; Suprasanna, P.; Das, B.K. Antioxidant Defense and Ionic Homeostasis Govern Stage-Specific Response of Salinity Stress in Contrasting Rice Varieties. Plants 2024, 13, 778.
Abstract
Salt stress is one of the most severe environmental stresses limiting the productivity of crops, including rice. However, there is a lack of information on how salt-stress sensitivity varies across different developmental stages in rice. In view of this, a comparative evaluation of contrasting rice varieties CSR36 (salt tolerant) and Jaya (salt sensitive) was conducted, wherein NaCl stress (50 mM) was independently given either at seedling (S-stage), tillering (T-stage), flowering (F-stage), seed-setting (SS-stage) or throughout the plant growth, from seedling till maturity. Except for S-stage, CSR36 exhibited improved NaCl stress tolerance than Jaya, at all other tested stages. Principal component analysis (PCA) revealed that the improved NaCl stress tolerance in CSR36 coincided with enhanced activities/levels of enzymatic/non-enzymatic antioxidants (root ascorbate peroxidase for T- and S+T stages and root catalase for F-, S+T and S+T+F-stages) and higher accumulation of osmolytes (shoot proline for F-stage and S+T+F-stage), indicating better antioxidant capacitance and osmotic adjustment, respectively. In contrast, higher shoot accumulation of Na+ and consequent increase in Na+/K+, Na+/Ca+2 and Na+/Mg+2 ratio in root and shoot, were identified as major variables associated with NaCl stress induced growth reduction in Jaya. In addition, CSR36 exhibited higher levels of Fe3+, Mn2+ and Co3+ and lower Cl- and SO42-, suggesting its potential to discriminate essential and non-essential nutrients, which might contribute to NaCl stress tolerance. Taken together, the findings provided the frame-work for stage-specific salinity responses in rice, which will facilitate crop-improvement programs for specific ecological niches including the coastal regions.
Rice, salt stress, stage-specific salinity, antioxidant defense, ionic homeostasis, salt tolerance
Keywords
Rice; Salt Stress; Stage-specific salinity; Antioxidant defense; Ionic homeostasis; Salt tolerance
Subject
Biology and Life Sciences, Plant Sciences
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.