Can Arabidopsis AP1 Gene Shorten the Juvenility of Apple?

Shortening of the juvenile phase is of great importance for apple breeding. Compared to conventional breeding methods, gene technology is more straightforward in reducing juvenility, as it can directly regulate expression of flowering-time genes. In model plant Arabidopsis, a number of flowering-time genes have been identified and characterised. Some of them have also been isolated from other species. Regulation of these genes has been proved to promote early flowering in a number of plant species. In this study, we have introduced the Arabidopsis APETALA1 (AP1) gene into the apple rootstock M26. The transgenic plants have been grown in the greenhouse for two years; however, no early flowering has been observed, although the AP1 gene is constitutively expressed in the transgenic clones, confirmed by RT-PCR analysis.