Effect of salicylic acid on antioxidant activity in milk thistle hairy root cultures

Elicitors can trigger defense responses and activate specific genes involved in secondary metabolite biosynthesis. For understanding SA-treatment signaling pathway we determined defense-related compounds and enzymes in S. marianum hairy root cultures. 28 day old hairy roots were treated by salicylic acid [6 mg/50 ml culture] for different times [24, 48, 72, 96 and 120 h]. The antioxidant activity was assayed by the 1-diphenyl-2-picrylhydrazyl stable free radical method and results were calculated based on the IC[50] H[2]O[2], peroxidase and ascorbate peroxidase activity and total tocopherol content was measured in treated and non-treated hairy root cultures. The highest accumulation of H[2]O[2] was 86.60 micro mol g[-1] DW that was obtained 120 h after elicitation [2-times of non-treated hairy roots]. IC[50] increased upon treatment and was 1.15- times higher than the control 24h after elicitation. The content of total tocopherol content under SA treatment was lower than the control experiments. Maximum activity of peroxidase and ascorbate peroxidase were 0.17 and 1.50 micro mol min[-1] mg[-1] protein, 96 and 72 h after elicitation, respectively. Oxidative stress defends system can be activated by salicylic acid in Silybum marianum hairy root cultures. This study suggested that exogenous SA can increase H[2]O[2] content of hairy roots, and induce the expression of antioxidant enzymes and increase secondary metabolite accumulation

Overview on tissue culture, regeneration and gene transfornation to Artemisia annua L.

Artemisia annua L. a highly aromatic annual herb is a widely dispersed through out the temperate region containing the main active anti malaria compound artemisinin a sesquiterpene lactone. Because of low artemisinin level, unsuccessful chemical synthesis and slightly improvement of molecular breeding methods, biosynthesis of this valuable compound was noticed by using the tissue culture and Genetic Engineering in these years. The rate transformation could be varies with different factors like genotype, age, explant type and agrobacterium strain. The results recently was shown that explants in tissue cultures are very sensitive to kanamycin concentration and even it could be late shoot and root formation. Hairy root culture is another subject that is in these years was niticed as a alternative method by designing the new bioreactor for production if this secondrary metabolite