Fig. 4.

Flowering time and floral phenotypes of transgenic Arabidopsis plants overexpressing MtSVP1 and MtSVP2. (A) Graphs showing the effect of ectopic expression of MtSVP1 (left) and MtSVP2 (right) on the flowering time of Arabidopsis WT Col. The flowering time of transgenic T₂ plants from four independent 35S:MtSVP1 Col lines (n=17–19) and five independent 35S:MtSVP2 Col lines (n=15–18) is shown. Col WT plants were grown as a control (n=9–24). Plants were grown in LD until they flowered. Flowering time was measured as the total number of rosette and cauline leaves at flowering and is shown as the mean ±SE. The flowering time of the 35S:MtSVP lines was significantly different from WT (P <0.01; t-test) except for MJ258. (B) Overexpression of MtSVP2 complements the Arabidopsis svp-41 mutation. Histograms showing the flowering time measured as the total number of rosette and cauline leaves at flowering of svp-41 mutants (n=6), WT Col (n=5), and three segregating T₂ populations from the overexpression of MtSVP2 in the Arabidopsis svp-41 background (n=10–12). (C) Photograph showing the delayed flowering phenotype of transgenic Arabidopsis plants overexpressing MtSVP1 (right) compared with WT Col of the same age. (D–O) Photographs of inflorescence, flowers, and siliques of WT Col (D, N) and transgenic plants from 35S:MtSVP1 (E–I) and 35S:MtSVP2 (J–M, O) Col lines. Plants overexpressing the MtSVP genes displayed variable floral abnormalities that include failure of sepals to enclose the floral bud at the early stages of development (arrowheads in E and J); irregular number of petals (F, K), sepals (H), and anthers (arrowheads in F and K); splayed arrangement of floral organs (I, M); enlarged carpels (arrowheads in I and M); sepaloid (green) petals (arrowheads in G and L); longer pedicel than WT (arrow in J); and lack of sepal abscission in wrinkled, narrow siliques (O).