Geminivirus-Mediated Delivery of Florigen Promotes Determinate Growth in Aerial Organs and Uncouples Flowering from Photoperiod in Cotton
Figure 5
F1 progeny of crosses with a VIF-treated parent have expected traits and are virus-free.
(A) The shape of main-stem leaves harvested from nodes 8–9 of TX701, DP61, and the F1, as labeled. TX701 leaves exhibit the okra leaf phenotype with five deep lobes and reduced lamina area. DP61 exhibits the normal leaf phenotype with three smaller lobes and a well-expanded lamina. The F1 from the DP61 × FT-induced TX701 cross exhibit an intermediate phenotype with leaves having five lobes of intermediate length. (B) Node of first fruiting branch is intermediate in the F1 population. Under non-inductive long days, the F1 produce floral buds (n = 46) in contrast to the TX701 parent which does not demonstrate reproductive growth by node 25 (n = 8 plants). Day-neutral DP61 produce floral buds earlier in development (n = 6 plants). (C) The maternal DP61 flowers (top) do not have the flower spots characteristic of the paternal TX701 pollen donor (see Fig. 3c); F1 progeny flowers (bottom) have the flower spot trait. (D) dCLCrV is not transmitted to the F1 progeny. From left to right, the viral Rep gene is not detected in uninfected DP61 or TX701 (lanes 1 and 2), nor in 9 different F1 progeny plants (lanes 3–11, collectively labeled F1), but is readily detected by PCR from a dCLCrV::FT-infected plant (lane 12, labeled dCLCrV::FT; this is the same plant shown in Fig. 3A and E, lane 6) and from a plasmid template (lane 13, labeled +). Detection of the endogenous magnesium chelatase subunit I (ChlI) serves as an internal control (plasmid control in the case of lane 13, +). No sequences were amplified in the absence of DNA (lane 14, labeled -).