Study On Correlation Between H₂O₂Scavengingsystem And Flavonoids Accumulation And DHAR Gene Of Agrobacterium Tumefaciens-mediated Transformation Of Scutellaria Callus

As the active ingredient of Scutellaria Baicalensis, Georgi, its anti-cancer,anti-HIV, anti-oxidation, and a variety of biological functions, to become aresearch hotspot in recent years around the world. In this study, the relationshipbetween ROS metabolism and active ingredients of medicinal plants under stressaccumulation mechanism as the starting point, based Scutellaria callus, analyze theimpact of environmental factors on the synthesis and decomposition of flavonoidsin Scutellaria and active oxygen metabolism in the use of Plant physiology,molecular biology, and other means, Depth study the Correlation of ROSmetabolism and flavonoid accumulation mechanism under the the adversitypressure of the temperature, moisture, light, Designed to explain the contactbetween resilience mechanisms and flavonoids accumulation mechanism of herbs.And using genetic engineering techniques To construct a plant binary vector,transferred exogenous DHAR to the callus of Scutellaria successfully byAgrobacterium-mediated, To improving the activity of active oxygen scavengingenzyme, thereby increasing the ability of plant resistance to oxidative stress, andenhance the quality of medicinal Scutellaria. Results are as follows.(1) The content of total flavonoid and the activity of PAL increasedsignificantly in12days after40℃, dark and PEG stress, meanwhile the activity ofPAL significantly increased also, that indicate moderate environmental stress couldpromote the accumulation of total flavonoids in S. baicalensis, the rate ofaccumulation is in propotion to the activity of PAL(r=0.830). In comparison, Theaccumulation of flavone and activity PAL was restrained under NPA+40℃,NPA+dark, NPA+PEG stress. It indicate that NPA can supress the synthesisof flavone of Scutellaria baicalensis.(2) Around12days after NPA, NPA+40℃,40℃, NPA+dark, dark and PEGstress, the content of baicalin declined and the content of baicalein rise, the activityof POD showed an increasing trend, the rate of baicalein accumulation is inpropotion to the activity of POD(r=0.818).(3) Around12days after NPA, NPA+40℃,40℃, NPA+dark, dark and PEGstress, the content of baicalin declined and the content of baicalein rise, the activityof POD showed an increasing trend, and level of H2O2remain stable. indicate thatModerate environmental stress could promote the accumulation of total flavonoidsin S. baicalensis, baicalin convert to baicalein by POD, and maintaining thestability of H2O2content to avoid oxidative damage.(4) Construct plant binary vector of dehydroascorbate reductase gene pCAMBIA1305-DHAR, and import it into Agrobacterium tumefaciens EHA105Successfully.(5) Transferred exogenous DHAR to the callus of Scutellaria successfully byEHA105, Through the test of the hyg and purpose gene, Established the system totransferred exogenous DHAR to the callus of Scutellaria successfully byAgrobacterium-mediated.The heoretical meaning of this study is to clarify the correlation between H2O2scavenging system and flavonoids accumulation of Scutellaria and The causes ofthe formation of the medicine quality, Support further research of antioxidantability by genetic engineering methods, and cultivate better species of radixscutellariae.