Table 1.
Ectopic expression of flower inducing genes in woody perennial fruit trees.
Figure 1.
Phenotypic characteristics of FT plums.
A regenerating FT plum line in vitro (A). Flowers on FT plum line #3 two months after planting in soil (B). One year old FT plum line #157 with ripe fruits (C). Cross and longitudinal sections of FT plum fruit (D) and dried seeds (stones) (E). Shrub architecture of one year old FT plum line #157 canopy (F) normal plum (G). Example of a downward branch angle in FT plum line #157 (H). Multiple flowers emerging from a single bud (I) and a resulting flower panicle (J). A flower is shown in which sepals, petals and anthers were removed revealing four carpels (K) that when pollinated produce multiple fruits (L). FT plum line #3 with ripe fruit after 28 months of continuous growth in the greenhouse (M). Flowers (fl), immature fruit (if), and ripening fruits (rf) on a single FT plum plant (N).
Table 2.
Gene expression and copy ratio of PtFT1 in transgenic plums.
Figure 2.
FT plums do not respond to cold treatment.
Graph showing mean percentage of bud break (Y axis) after transfer to greenhouse upon selected intervals of chilling time (X-axis) measured for up to four weeks (Z-axis) (A).Images of cold treated FT line #34 (B) and normal (C) plums after indicated chilling times at 4°C.
Figure 3.
FT plums do not set terminal buds under short day lengths.
Vegetative meristems from control plums showing terminal buds when grown under an 8 hr day length (A) but not under 16 hrs (B). Growth pause in FT plum line #34 grown under an 8 hr day length (C) and continued growth under 16 hr (D) days.
Figure 4.
Growth habit, flowering, and fruiting of field grown FT plums.
FT plum line #34 (120 cm in height) shown flowering six weeks after the normal anthesis period (first week in April) (A). A non-transgenic control plum (190 cm in height) of the same age that does not flower (B). Resumed flowering of FT plum line #34 in fall (last week of October) (C).
Figure 5.
Flowering in field grown FT plums correlates with temperature.
Graph showing the percentage of PtFT plums that flowered each month (top) and the average monthly air temperature (bottom). Monthly dates are shown on X-axis. Shaded gray bars indicate periods of significant flowering. Small black bar on X-axis indicates the observed flowering period of control plums.
Figure 6.
High temperature represses flowering.
(A) Graphs showing differences in flowering of FT line #3 and control plums grown either under 21°C or 29°C. Y-axis represents number of flowers produced per week measured over a period of 3 weeks (left). After temperature swap, flowers were measured for a 3 week interval and shown as number per node (right). (B) Image of a typical abnormal leaf-like flower produced only at 29°C. (C) Image of flowering plants after temperature swap of FT line #3 either shifted or maintained at 21°C or 29°C. Error bars represent standard deviation.
Table 3.
Primer sequences used to amplify PtFT sequences in the transgenic plum leaves.