Evaluation of transgenic Campanula carpatica plants :

Abstract: In Campanula carpatica, the general problem is that the flowers are very sensitive to exogenous ethylene. Flowers that are exposed to ethylene wilt in two to three days. Treating the plants with anti-ethylene compounds can prevent the problems with ethylene. However, these compounds are very expensive and environmentally dangerous. The advances in genetic engineering and transformations with the mutant etr1-1 gene in, e.g. carnations and petunia have led to plants of the Campanula carpatica cultivars ‘Blue Uniform’ being transformed with the gene etr1-1 in order to resist the effects of ethylene. The transformation of the plants resulted in transformed shoots that were grown in tissue culture and later planted in greenhouses. These different shoots were called lines and were given different numbers. The transformed plants were tested for their sensitivity to ethylene. A total of 20 different transgenic lines of the Campanula carpatica were evaluated. To determine whether there were any differences in plant morphology after they had been transformed with the etr1-1 gene, morphological studies were performed. For the transformed plant to be suitable for use in further plant breeding, the flowers, and especially the pollens, had to be investigated. Pollen was tested for viability, growth of the pollen tube, and finally, crossing was done to prove the viability. The lines were divided into three groups depending on percentage viability or percentage of grown pollen tubes. Group A included lines Aglo 2, Aglo 3, Aglo 4 and SF 28-1. Group B included lines SF 15-1 and ‘Blue Uniform’ control. Group C included line SF 13-1. To confirm that the gene etr1-1 was inserted in the plants, they were also tested using polymerase chain reaction (PCR). ELISA analyses were performed to investigate the presence of nptII in the transformed lines. The final results revealed that the lines SF 15-1, SF 15-1c, SF 15-1de, SF 15-4 and GH 4 had a low sensitivity to ethylene. These plants had no morphological differences. However, the lines Aglo 1, Aglo 2, Aglo 3, Aglo 4 and Aglo 8.3 lacked hairs under the leaves and on the stem parts. Line SF 11-2 displayed a different pattern of plant growth with a pointier growth behaviour of the buds and leaves, while the lines SF 13-1 and SF 13-1a grew much taller than the other lines. The lines SF 15-1, SF 15-1c, SF 15-1de, SF 15-4 and GH 4 (especially SF 15-1) had fertility values that were close to the control plants. In the PCR, lines SF 15-1, SF 15-1c, SF 15-1de, SF 15-4, SF 13-1, SF 13-1a and GH 4 amplified the gene etr1-1. In lines SF 13-1 and SF 13-1a the gene etr1-1 was amplified, but these plants were sensitive to ethylene. I think the gene etr1-1 was silenced in the flowers or in the plant itself.