No abstract

In the process of the production of recombinant proteins by using an Agrobacterium-mediated transient gene expression system, the effectiveness of the control of light conditions pre- and post-agroinfiltration on efficiency of transient expression is worth being evaluated. In this study, Nicotiana benthamiana seedlings were used as a bioreactor to investigate the effects of different light conditions pre- and post-agroinfiltration on the transient expression of green fluorescent protein (GFP). The present results showed that the seedlings grown under light condition for 5 weeks had highest level of transient expression among those grown for 4-8 weeks. In the pre-agroinfiltration, the level of transient expression of GFP was obviously decreased by the increase in light intensity or by the shortening of the photoperiod. Although the shortening of the photoperiod post-agroinfiltration also decreased the level of transient expression, moderate light intensity post-agroinfiltration (100 to 200 μmol·m-2·s-1) was needed for higher level of transient expression efficiency. Totally, there was no strong correlation between the transient expression efficiency and plant growth under different light conditions. These results suggest that light condition is an important factors affecting the level of transient expression in plants. The effects of light intensity and photoperiod in the post-agroinfiltration on the transient expression efficiency are obvious difference from those in the pre-agroinfiltration. Hence, light conditions should be optimized to obtain higher productivity of recombinant protein from transient expression systems.