Antisense Expression of MdTFL1, a TFL1-like Gene, Reduces the Juvenile Phase in Apple

in Journal of the American Society for Horticultural Science
View More View Less
  • 1 Department of Apple Research, National Institute of Fruit Tree Science, Incorporated Administrative Agency, National Agriculture and Bio-oriented Research Organization (NARO), Shimo-kuriyagawa, Morioka 020-0123, Japan

Because fruit trees such as apple (Malus ×domestica Borkh.) flower and set fruit only after an extended juvenile phase lasting several years, efficient breeding of fruit trees is limited. We previously suggested that MdTFL1 (Malus ×domestica TFL1) functions analogously to TERMINAL FLOWER 1 (TFL1) and that MdTFL1 is involved in the maintenance of the juvenile/vegetative phase in apple. To clarify the function of MdTFL1 in apple, we produced transgenic `Orin' apple trees expressing MdTFL1 antisense RNA. One of them flowered only 8 months after the transfer to the greenhouse, whereas the nontransformed control plants have not flowered in nearly 6 years. As expected, the expression of endogenous MdTFL1 was suppressed in the transgenic lines that showed precocious flowering. In addition, the expression level of the transgene was correlated with the reduction of the juvenile phase. These findings confirm that MdTFL1 functions like TFL1 and that MdTFL1 maintains the juvenile and vegetative phase in apple. Flower organs of the transgenic apple trees were normal in appearance, and a precocious flowering transgenic line set fruit and seeds. Interestingly, some flowers of the transgenic apple trees developed without undergoing dormancy. The expression of MdTFL1 in apple may affect flower development as well as flower induction.

If the inline PDF is not rendering correctly, you can download the PDF file here.

Contributor Notes

Corresponding author; e-mail address:
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 621 173 7
PDF Downloads 614 238 6