Seed Priming Modulates Germination Potential, Osmoprotectants Accumulation and Ionic Uptake in Wheat Seedlings under Salt Stress

Increasing salinity is a major threat to crop growth and development while seed priming can effectively induce salt tolerance in plants. The present study examined the role of ascorbate priming (ascorbate; 50 mg L-1), hormonal priming (triacontanol and indole acetic acid; 25 and 100 mu mol, respectively) and osmolyte priming (proline; 50 mM) in wheat seedling grown under NaCl based salinity (12 dS m(-)(1)) as well as normal (3 dS m(-1)) conditions. The results indicate that priming with triacontanol (TRIA) followed by ascorbate (AsA) priming alleviated the detrimental effects of salinity stress by reducing germination time accompanied by improved germination index and final germination. Enhanced seedling growth in terms of better root and shoot lengths, seedling fresh and dry biomass were recorded in primed seeds. Under both conditions, all priming treatments successfully improved physio-biochemical traits. Maximum chlorophyll, glycine betaine and potassium contents were recorded in seedlings obtained from seeds primed with AsA and TRIA priming. Pre-soaking with IAA produced highest proline and total soluble sugars while osmolyte priming showed minimum Na+ contents and maximum K+/Na+ ratio as well as total phenolic contents under salt stress. Plant biomass was positively linked with chlorophyll stability and osmoprotectants accumulation under saline conditions. In crux, triacontanol and ascorbate are the most effective priming agents to induced salt tolerance in wheat, attributed to improved germination with vigorous stand and decreased salt damage due to enhanced osmoprotectants. (C) 2019 Friends Science Publishers