Long term, transgene expression in Lilium longiflorum 'Nellie White' grown outdoors and in the greenhouse

Lilium longiflorum cv. Nellie White plants were transformed with either the bar-uidA fusion gene or the nptII and uidA genes and grown for two seasons in the greenhouse and outdoors in containers. All transgenes were under control of the CaMV 35S promoter. During the first year there was no difference in bar protein level between plants grown in the greenhouse and outdoors, but the second year two of the seven transgenic plant lines grown outdoors showed a significantly higher level of the bar protein than plants grown in the greenhouse. The relative level of bar protein expression between all seven transgenic plant lines remained the same for lilies grown in the greenhouse and outdoors during two growing seasons. One plant line contained the nptII gene, and nptII protein expression was comparable when plants were grown in the greenhouse or outdoors for two seasons. Four plant lines expressed GUS as determined by histochemical staining of their leaves. Three of these four plant lines showed dark blue staining along the cut edges of the leaf when plants were grown either in the greenhouse or outdoors for both seasons. The fourth plant line showed either dark blue staining along the cut edge of the leaf or small, light blue spots on parts of the leaf depending on the plant stained. Expression of the three genes was confirmed using semi-quantitative RT-PCR.