Physiological And Biochemical Response Of Ophiopogon Japonicas Pubescens To Cadmium Stress And Mitigative Effects Of Exogenous GSH Treatment

A pot experiment was conducted to explore the effects of varity concentrations(0,25,50,75,100,150,200mg/kg)Cd,and the regulatory pathway of(30,60,90mg/L)of exogenous GSH under Cd treatment on the growth of Ophiopogon Japonicas.The experimental results showed that:(1)The results showed that the 25mg/kg Cd stress had no significant effect on the biomass and photosynthetic rate of Ophiopogon Japonicas,and high concentration Cd treatment(?50mg/kg)significantly inhibited the growth and biomass accumulation of Ophiopogon Japonicas?With the increasing concentration,of Cd treatment,the content of Malondialdehyde(MDA)and superoxide anion in leaves significantly increased comparing with CK,and the activity of SOD and CAT exhibited significant "low promoting suppression" phenomenon.The content of Cd in the roots had significant increased under Cd treatment,and the Cd content in roots reached 291 mg/kg when the Cd concentration was 200mg/kg.All of Cd concentration treatment did not lead to withered and death during the pot experiment,which showed that Ophiopogon Japonicas has a strong tolerance under Cd treatment,and provided the potential for remediation of urban Cd-contaminated soil.(2)Compared with 150mg/kg Cd treatment,exogenous GSH(30,60,90mg/l)with different concentrations can effectively relieve the stress damage of Cd on the Ophiopogon Japonicas,and the effect of the alleviation is most significant when GSH concentration is 60mg/L.Compared with 150mg/kg Cd treatment,60mg/L GSH can significantly increase plant biomass,photosynthetic rate and chlorophyll content,enhance root membrane protection system,active oxygen scavenging system and increase the activity of antioxidant enzymes SOD,CAT,GR and APX in leaves and roots,It can also improve the content of antioxidant ASA,GSH and NPT in the plants,and the content of Cd in the leaves and roots was decreased by 77.1% and 13.4% respectively.To sum up,appropriate concentration of exogenous GSH can effectively alleviate the toxicity of Cd stress by increasing photosynthesis,reducing oxidative damage,and inhibiting free Cd transport to shoots.the application of appropriate concentration of GSH can improve photosynthesis,reduce oxidative damage,inhibit the Free State of the CD to the ground transport,thereby effectively alleviating the CD stress on the edge of grass toxicity.