Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/12/2008
Publication Date: 3/14/2009
Citation: Kamo, K. 2009. Transgene expression for Gladiolus plants grown outdoors and in the greenhouse. Scientia Horticulturae. 11:275-280.
Interpretive Summary: Gladiolus is an important floral crop that could benefit from genetic engineering for virus resistance. Viruses remain in the plant when they are propagated each year by bulbs. Viruses affect the appearance of the leaves, flowers, and whole plant by causing streaking of flowers and leaves and decreasing the vigor of the plant. Successful genetic engineering requires that the antiviral gene be expressed when the Gladiolus plants are grown outdoors. Most of our studies on gene expression in Gladiolus plants have used plants grown in vitro or in the greenhouse to follow federal guidelines for containment of transgenic plants. This study compared transgene expression in plants grown two years in the greenhouse and outdoors. It was concluded that the level of transgene expression was higher outdoors in 3/12 plant lines than in the greenhouse (1/12 plant lines).
Technical Abstract: Transgene expression was evaluated for Gladiolus plants transformed with either the CaMV 35S, double CaMV 35S, rolD, or Arabidopsis UBQ3 promoter controlling the uidA or bean yellow mosaic virus coat protein gene in either the sense or antisense orientation to determine differences in expression for plants grown in the greenhouse and outdoors for two years. There was more variability in GUS expression when plants were grown outdoors rather than in the greenhouse for two years. Four of the six transformed plant lines with the UBQ3, rolD, and CaMV 35S promoters grown outdoors as compared to two of the six lines with the UBQ3 and rolD promoters grown in the greenhouse showed significant differences in GUS expression from year to year. When grown the same year two plant lines with the CaMV 35S and rolD promoters showed 2-6X higher levels of GUS expression outdoors rather than in the greenhouse, and one plant line with the CaMV 35S promoter had 3X higher GUS expression in the greenhouse instead of outdoors. Five of six plant lines transformed with the bean yellow mosaic virus coat protein gene in either the sense or antisense orientation under control of the double CaMV 35S promoter showed comparable levels of transgene expression for both years when plants were grown both outdoors and in the greenhouse. One plant line with the double CaMV 35S promoter showed higher levels of coat protein gene expression for plants grown outdoors rather than in the greenhouse.