Rice seed priming with sodium selenate: Effects on germination, seedling growth, and biochemical attributes

The aim of this study was to determine the effects of sodium selenate (15, 30, 45, 60, 75, 90, and 105 mg kg(-1)) on the germination and seedling growth of Changnongjing 1 rice (Oryza sativa L.) at 25 degrees C and 30 degrees C. Low selenate concentrations induced shorter and more uniform germination periods than did ultrapure water at both temperatures. Seedlings primed with low selenate concentrations were superior to those primed with ultrapure water in terms of plant height, fresh weight, dry matter accumulation, and soluble carbohydrate and protein contents. Lower selenate concentrations (15-75 mg kg(-1)) induced higher chlorophyll and phenol contents in seedlings than did ultrapure water. Lower selenate concentrations also increased the superoxide dismutase (SOD), peroxidase (PDX), catalase (CAT), and glutathione peroxidase (GPx) contents in seedlings and significantly decreased the stress-related malondialdehyde (MDA) content compared to ultrapure water. In conclusion, rice seedling germination and growth were promoted by priming with low selenate concentrations (15-75 mg kg(-1)) but inhibited by priming with high selenate concentrations (90-105 mg kg(-1)).