Plant architecture is an important agronomic trait driven by meristematic activities. Indeterminate meristems set repeating phytomers while determinate meristems produce terminal structures. The centroradialis/terminal flower1/self pruning (CETS) gene family modulates architecture by controlling determinate and indeterminate growth. Cotton (G. hirsutum) is naturally a photoperiodic perennial cultivated as a day-neutral annual. Management of this fiber crop is complicated by continued vegetative growth and asynchronous fruit set. Here, cotton CETS genes are phylogenetically and functionally characterized. We identified eight CETS genes in diploid cotton (G. raimondii and G. arboreum) and sixteen in tetraploid G. hirsutum that grouped within the three generally accepted CETS clades: flowering locus T (FT)-like, terminal flower1/self pruning (TFL1/SP)-like, and mother of FT and TFL1 (MFT)-like. Over-expression of single flower truss (GhSFT), the ortholog to Arabidopsis FT, accelerates the onset of flowering in Arabidopsis Col-0. In mutant rescue analysis, this gene driven by its native promoter rescues the ft-10 late flowering phenotype. GhSFT upstream sequence was used to drive expression of the uidA reporter gene. As anticipated, GUS accumulated in the vasculature of Arabidopsis leaves. Cotton has five TFL1-like genes, all of which delay flowering when ectopically expressed in Arabidopsis; the strongest phenotypes fail to produce functional flowers. Three of these genes, GhSP, GhTFL1-L2, and GhBFT-L2, rescue the early flowering tfl1-14 mutant phenotype. GhSPpro:uidA promoted GUS activity specifically in plant meristems; whereas, other GhTFL1-like promoters predominately drove GUS activities in plant vascular tissues. Finally, analysis of Gossypium CETS promoter sequences predicted that GhSFT, GhSP, GhTFL1-L1, GhTFL1-L2 and GhBFT-L2 are regulated by transcription factors involved in shoot and flowering development. Analysis of cotton's two MFT homologs indicated that neither gene functions to control shoot architecture. Our results emphasize the functional conservation of members of this gene family in flowering plants and also suggest this family as targets during artificial selection of domestication.
