Effect of Exogenous Abscisic Acid on Tolerance of Wheat Seedlings to Cadmium Stress

Effects of exogenous abscisic acid(ABA) on the growth and some physio-biochemical signs in wheat(Triticum aestivum L.) seedlings under cadmium stress(100 mg/L) were studied with hydroponics.The results showed that:(1)The malondialdehyde(MDA) content in wheat seedlings was significantly increased(P0.05),and the growth of wheat seedlings was also obviously inhibited by Cd2+ stress.(2)Exogenous ABA with the concentration of 5.0 μmol/L playing a noticeable role increased root activity and proline content,enhanced activities of SOD,POD and CAT,and decreased MDA content.(3)Exogenous 1.0-5.0 μmol/L ABA eased the negative effects of Cd2+ on the growth of wheat seedlings,and 5.0 μmol/L ABA worked best with shoot height,root length and total biomass of seedlings in 5.0 μmol/L ABA and Cd2+ stress had increased 6.73%,149% and 10.52%,respectively,compared with those under single Cd2+ stress.However,10.0 μmol/L ABA exacerbated the growth of wheat seedlings.On the whole,preference concentration of exogenous ABA could ease the inhibitory effects of Cd2+ stress on the growth of wheat seedlings and boost the tolerance of wheat seedlings to Cd2+ stress by increasing SOD,POD and CAT activities and proline content.Furthermore,the most suitable concentration of ABA was defined to be 5.0 μmol/L.