| Ozone is current considered to be the important gaseous pollutant in our environent.To study the effects of ozone in ginkgo leaves on transcriptional level,we applied 4-year-old ginkgo in OTCs as materials.The ozone concentration in the natural conditions as the control group,and set three ozone concentration gradient:80 nmol·mol-1 and 120 nmol·mol-1 and 200 nmol·mol-1.In this experiment,we studied the the accumulation of H2O2 and O2-.produced rate,the effects of high concentration O3 on the activity of antioxidant enzymes activity.Moreover,the study use q RT-PCR to detection the effect of high concentration ozone on antioxidant enzymes genes expreesion.The results show that:?1?Under long-term ozone stress conditions,the generation rate of superoxide free radicals and hydrogen peroxide content in ginkgo leaves were increased with the ozone concentration.?2?The 80 nmol·mol-1concentration of ozone treatment promoted the synthesis of As A and enhanced the redox capacity of As A,but the 200 nmol·mol-1 concentration of ozone treatment inhibited the production of As A and reduced the ratio of As A / DHA.However,ozone stress could increased the content of GSH in ginkgo leaves,but the ratio of GSH / GSSG would be inhibited under 200 nmol·mol-1 high concentration of ozone fumigation.?3?Under short-term ozone stress,the activity of SOD increased,while the activity of SOD decreased under long-term ozone stress.However,under short-term high concentration of ozone,the activity of CAT in Ginkgo biloba leaves was increased,but at the initial stage of the experient,APX played the major role in the removal of H2O2.?4?The antioxidant enzymes such as POD,CAT,APX and Fe-SOD in G.B leaves were rapidly induced in the early stage of ozone stress.However,the expression of Mn-SOD,Cu / Zn-SOD and GST gene was significantly up-regulated after 40 days of stress treatment.Interestingly,the GST gene was up-regulated only under 80 nmol·mol-1 concentration of ozone stress. |
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