Effects of water stress and rehydration on physiological characteristics of Scutellaria baicalensis Georgi
The physiological response of Scutellaria baicalensis Georgi(SBG)to varying water stress and rehy-dration treatments was investigated using authentic SBG.Potting soil moisture was set at 100％,80％,60％,and 40％of the field water-holding capacity to represent four conditions:excessive water supply,moderate water sup-ply,mild water deficit,and severe water deficit,respectively,with 80％FC(moderate water supply)as the con-trol.The results showed that,at 30 days of water stress,the total chlorophyll content of SBG subjected to the stress treatments(100％FC,60％FC,and 40％FC treatments)reduced by 7.1％,5.6％,and 5.9％,and the carotenoid content reduced by 6.5％,10.1％,and 9.3％,and the relative exocytosis rate of electrolytes elevated by 46.5％,19.7％and 54.9％,respectively,in the stress treatment compared with the control treatment.Malondialdehyde con-tent of SBG elevated by 39.7％,109.7％,and 360.0％,superoxide dismutase activity elevated by 2.3％,3.8％,and 7.5％,and glutathione reductase activity elevated by 97.4％,105.5％,and 172.5％,respectively,compared with the control treatment.In addition,during water stress,water deficit treatments(60％FC and 40％FC treat-ments)led to an increase in the soluble sugar content of SBG,which amounted to 49.7 mg·g-1 and 57.8 mg·g-1 at 30 days of stress,respectively.The excess water supply treatment(100％FC treatment)led to an increase in the peroxidase activity of SBG,which amounted to 3.99 mg·g-1·min-1 at 30 days of stress.Rehydration was effective in reducing physiological damage caused by water stress.During rehydration and harvest,chlorophyll in SBG from the stress treatments(100％FC,60％FC,and 40％FC treatments)was restored in excess,and the total chlorophyll content elevated by 5.5％,9.1％,and 18.2％,respectively,compared with that of the control treatment at 5 days of rehydration.The proline content of the stressed treatments decreased to around 52.2 mg·g-1 with the control treatment.Physiological damage caused by heavy water deficit could not be recovered by rehydration,and soluble sugar content reached 28.6 mg·g-1,malondialdehyde 9.2 mg·g-1,superoxide dismutase activity 919.9 U·g-1·h-1,and peroxidase activity 2.0 mg·g-1·min-1 in the 40％FC treatment at harvest,all of which were at higher levels among treatments.Water stress and rehydration favored the yield quality of SBG roots,and at harvest,the 60％FC treatment had the highest harvest of baicalin at 629.14 mg per plant.
万方数据
维普
