The Research On Cucumis Melo (L.cv Hetao) Transformed With A Vector And Marker-Free Antisense ACO1 Gene

In this research, we used the plant binary expression vector pPZP221(35S-Nos) as the initial vector. Removing the gentamycin acetyltransferase gene aacCl by digestion with Mssâ… ,Vspâ… and inserting the CaMV 35S promoter and nos terminator sequence, we get the marker-free vector pPZP201(35S-Nos). The cDNA clone of the ACC oxidase gene (ACO1) from melon were constructed reversely into pPZP201 (35S-Nos), named pPZP201-ACO1. The vector backbone and marker-free 35S-ACO1-Nos cassette was obtained by digested pPZP201-ACO1 with Psyâ… ,Paeâ… . The cassette fragment was transformed into hetao melon by the pollen-tube pathway transgenic technology. The T1 transgenic strains with improved storage capacity were selected.The results are as follows:1)20 flowers were transformed and 18 fruits were harvest.4 fruits with high transformation rate of T1seeds were selected by PCR detection. Project 30660111 supported by National Nature Science Foundation of China 2) After two generation selection,4 strains with improved storage capacity have been selected. When the T0,T1 fruits with improved storage capacity strains were stored for 30 days, the firmness were 4.9 kg/cm2,4.95 kg/cm3, whereas the non-transgenic ones were rotted. And the sugar content was the same level between the non-transgenic melon and the transgenic melon (T0,T1). The endogenous ethylene concentration of transgenic fruits was about 3%-4% of the non-transgenic ones.3) The botany characters investigation of T 1 plants which showed improved storage capacity were the same as the non-transgenic ones. That means the antisense ACO1 gene did not influence the growth of the plants.4) The investigation of T 2 plants pollen morphology and pollen germination showed that there were not significantly differences between the transgenic plants and the non-transgenic ones. The nodes of andromonoecious of transgenic plants (11) were higher than the non-transgenic ones (8). Pedicel abscission phenotype of transgenic plants showed delayed abscission in vitro condition. And transgenic plants abscised an average of 0.4d later than non-transgenic ones.