Elucidating Morpho-Anatomical, Physio-Biochemical and Molecular Mechanism Imparting Salinity Tolerance in Oats (Avena sativa L.)

Abstract

Soil salinization drastically affects crop growth, development and yield. In order to tackle salinity, knowledge about stress tolerance mechanism is important to expedite the development of salt-tolerant cultivars. In this study, 20 oat genotypes consisting of 11 cultivated and nine wild Avena species were evaluated at different levels of salinity with 1:1 NaCl and Na2SO4 salts mixtures under hydroponics and pot experimental set-up. Drastic reduction was observed in chlorophyll, relative water and K+/Na+ contents, along with yield traits in sensitive genotypes (HFO-103, Kent and JHO-2000-4) when compared with tolerant (HJ-8, JHO-99-2, HFO-873 and HFO-878) under elevated salinity. Root anatomical section studies were also critical to screen salinity tolerance among the oat genotypes. Furthermore, the effect of salinity at the transcriptomic level resulted in upregulation of sodium/hydrogen exchanger and potassium transporter genes along with WRKY17 transcription factor, regulating the signalling and osmotic roles in tolerant genotypes (HJ-8 and HFO-873). The identified salt-tolerant oat genotypes reflected wide genetic diversity using SSR markers which can serve as a crucial donor for salt tolerance in oat breeding programmes.