Effects of salt stress on plasmalemma permeability, osmolyte accumulation and protective enzyme activities in oat plants.

摘要

A pot experiment was conducted with different salinities caused by NaCl and Na₂SO₄. The results showed that salt stress had great influence on growth and physiological activities of oat plants. The growth of oat plants was promoted under soil salinity of 0.2%, and the grain yield was similar to that in control. Under the soil salinity of 0.4%, the rate of oat seedling emergence was 75% of that in control, the water content in stem and leaf and root was about 80% of those of control. However, biomass yield was 71.24-72.67% in control, and grain yield was about 50% of that in control. The oat yield decreased about 70% under 0.6% soil salinity. Limiting salt concentration for yield formation was 0.8% and the seedling emergence of oat was 9% of that in control under the soil salinity of 1.0% that was lethal concentration. The plasmalemma permeability, peroxidation product, osmotic adjustment substances and protective enzyme activities in oat seedling leaf all increased under salt stress. The order of salinity-sensitive osmolytes under salt stress was soluble sugar, free proline, soluble protein and the salinity-sensitive order of protective enzyme was CAT, POD and SOD. The indexes that were significantly correlated with soil salinity were soluble sugar, free proline, grain yield, MDA, biomass yield, moisture content in stem, leaf and root, and relative electrical conductivity. There was no salinity stress on seedlings and plant physiology in oat plants when the soil salt concentration was less than 0.4%.