抄録
We investigated the effects of different photoperiods on the expression level of GUS genes regulated by the CaMV-35S promoter in leaf lettuce (Lactuca sativa L. cv. ‘Greenwave’) for a recombinant protein production system. A leaf disk experiment and a cultivation experiment were conducted in different photoperiods. A linear relationship (R2=0.9934) was observed between the lengths of photoperiods and GUS activities per unit fresh weight in the leaf disk experiment. This result indicates that the expression of the CaMV-35S promoter during a photoperiod was much more enhanced than that during a dark period. In the cultivation experiment, a longer photoperiod helped not only to enhance the growth of a lettuce plant but also to increase its GUS activity. As a result, GUS activity per plant under the 24:0 h photoperiod was significantly (P‹0.05) higher than that under the 16:8 and 8:16 h photoperiods. However, the question remains whether these results for GUS-CaMV-35S promoter can be applied to other recombinant proteins or promoters. Further studies are thus required to establish a practical strategy for designing an efficient recombinant production system in a plant factory.
