SA and PEG-Induced Priming for Water Stress Tolerance in Rice Seedling

An experiment was conducted to evaluate the effect of different seed priming methods to enhance the polyethylene glycol-6000 (PEG-6000) stress tolerance in rice (Oryza sativa L.). Seeds were subjected to different priming treatments such as water, PEG, and salicylic acid (SA). The primed seeds were grown for 8 days and then the seedlings were subjected to PEG (15%) stress. The different biochemical responses were studied 2 days after treatment. Under PEG stress, the root length was higher in PEG and SA-primed sets as compared to water-primed, while the shoot height had no change. SA-primed increased photosynthetic pigment content and Chla/Chlb of rice under PEG stress. Net photosynthetic rate and water use efficiency were higher in PEG and SA-primed sets as compared to water-primed under PEG stress. SA-primed enhanced the activities of superoxide dismutase and peroxidase, but decreased the activity of catalase under PEG stress. Pro line content was lower in PEG-primed, but higher in SA-primed as compared to water-primed treatment. The study thus suggests the use of SA-priming as a more effective strategy to alleviate the PEG induced stress in rice.