Influence of mild γ-irradiation on growth and paclitaxel biosynthesis in hazel (Corylus avellana L.) in vitro culture

Abstract

Using the in vitro culture system along with related strategies is one of the most promising sources to improve the production of antitumorous agent paclitaxel and other valuable bioactive metabolites. To the best of our knowledge, hazel is the only angiosperm plant that has the capacity to produce paclitaxel and other taxanes. In this study, stable 14-day-old calli initiated from fresh hazel cotyledons were exposed to low-dose γ-radiation for 3, 9, and 15 seconds, which produced 10, 20, and 30 Gy of radiation dose, respectively. Non-irradiated cultures were considered as control. The cultures were picked up after 2 weeks of exposure to radiation and the parameters measured. The results showed that radiation changed callus growth and cells viability. Instead, by increasing radiation dose, antioxidant potential, activity of phenylalanine ammonia-lyase enzyme, and biosynthesis of biochemicals such as paclitaxel signi cantly increased. A negative correlation was observed between studied biochemical traits including paclitaxel and callus biomass production. The highest paclitaxel speci c yield was measured in 30 Gy irritated calli which was 241.77 µg g -1 DW, 21.17 times higher than the control culture. Exposure to 30 Gy radiation resulted in the development of a new callus line with a stable high content of paclitaxel. It seems that by eliciting and varying cells, γ-radiation improved the metabolism in callus culture of hazel and could be used to produce such valuable metabolites on a commercial scale.