Upregulation of OsNAS1, OsPCS1, and DREB1A transcripts along with antioxidative defense confers salt tolerance in rice (Oryza sativa L. cv Pokkali)

• Published in: Archiv für Acker- und Pflanzenbau und Bodenkunde Vol. 62; no. 10; pp. 1381 - 1395
• Main Authors: Kabir, Ahmad Humayan, Zaman, Reshma, Begum, Most Champa, Haque, Ariful, Swaraz, A M, Noor, Iftekhar Mohammad, Alam, Mohammad Zahangir, Haider, Syed Ali
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02-10-2016; Taylor & Francis Ltd
• Subjects: Abiotic stress; amino acids; Antioxidant defense; Gene expression; glutathione; nicotianamine synthase; Oryza sativa; Salt; Soil sciences
• ISSN: 0365-0340; 1476-3567
• DOI: 10.1080/03650340.2016.1149817

This study investigated the mechanisms associated with differential salt tolerance in two contrasting rice genotypes (Pokkali and BRRI 3). Plant growth, leaf chlorophyll, and Na
+
concentrations were significantly affected in BRRI 3 but not in salt-tolerant Pokkali under salt stress. Further, salinity caused upregulation of two chelators named OsNAS1 (nicotianamine synthase) and OsPCS1 (phytochelatin (PC) synthase) along with PC accumulation in roots of Pokkali and BRRI 3, though the expression was more pronounced in Pokkali. It suggests that nicotianamine and PC may chelate excess Na
+
under salt stress. Furthermore, greater induction of DREB1A (a transcription factor) in Pokkali suggests that DREB1A may have involvement in salt-induced gene expression in rice. In Pokkali, salt stress caused significant increase in catalase, glutathione reductase, and superoxide dismutase activity only in roots along with enhanced production of glutathione, proline, arginine, methionine, cysteine, serine, and lysine in leaves. These results suggest that Pokkali plants possibly have better protection mechanism against salt-induced oxidative damage due to active antioxidant activities and higher accumulation of glutathione and proline. Taken together, our findings will be useful for transgenic and breeding programs for salt tolerance in rice.