To produce early flowering genotypes, plum (Prunus domestica) was transformed with the poplar (Populus trichocarpa) Flowering Locus T1 (PtFT1) gene. Ectopic expression of 35S::PtFT1 Induced early flowering in vitro from transgenic plantlets within two months of transformation. When the transgenic plum plants were rooted and transferred to soil and grown in posts in the growth chamber, a number of additional lines flowered. Normal flowering and fruiting were observed in the greenhouse within one year of transformation. While dormancy was not necessary for growth or fruiting, FT plums were still winter hardy and floral bud set and flowering responded normally to changes in temperature. By manipulating a single gene, temperate tree crops can be effectively engineered for cultivation in new growing areas and for entirely new modes of agricultural production that are continuous, sustainable, and adaptable to climate change.
