[hnprovement on the growth and nutrient absorption of Iris hexagona by exogenous salicylic acid under Cd stress].

The effects of exogenous salicylic acid (SA) pretreatment on the biomass, water content, photosynthesis, root vigor, Cd accumulation, nutrient absorption and antioxidant enzyme activity of Iris hexagona under Cd stress were studied by using Hoagland solution culture. The results showed that SA pretreatment promoted dry mass, root vigor and net photosynthetic rate of Cd-stressed I. hexagona seedlings. Compared with only Cd treatment, the Cd accumulation of Cd-treated plants with SA pretreatment remained unaffected, however,. SA pretreatment increased contents of N, P, S, and decreased K content. Activities of antioxidant enzymes of Cd-treated seedling root were increased under SA pretreatment. In conclusion, the improvement on growth of I. hexagona by SA pretreatment under Cd stress was attributed to improving Cd tolerance rather than reducing Cd uptake. The regulation of mineral element accumulation and the increase of antioxidant enzyme activities could be explained for Cd resistance improvement induced by salicylic acid.