Homologs ofFT,CENandFDrespond to developmental and environmental signals affecting growth and flowering in the perennial vine kiwifruit

Abstract

SummaryFLOWERING LOCUS T (FT) and CENTRORADIALIS (CEN) homologs have been implicated in regulation of growth, determinacy and flowering.The roles of kiwifruit FT and CEN were explored using a combination of expression analysis, protein interactions, response to temperature in high-chill and low-chill kiwifruit cultivars and ectopic expression in Arabidopsis and Actinidia.The expression and activity of FT was opposite from that of CEN and incorporated an interaction with a FLOWERING LOCUS D (FD)-like bZIP transcription factor. Accumulation of FT transcript was associated with plant maturity and particular stages of leaf, flower and fruit development, but could be detected irrespective of the flowering process and failed to induce precocious flowering in transgenic kiwifruit. Instead, transgenic plants demonstrated reduced growth and survival rate. Accumulation of FT transcript was detected in dormant buds and stem in response to winter chilling. In contrast, FD in buds was reduced by exposure to cold. CEN transcript accumulated in developing latent buds, but declined before the onset of dormancy and delayed flowering when ectopically expressed in kiwifruit.Our results suggest roles for FT, CEN and FD in integration of developmental and environmental cues that affect dormancy, budbreak and flowering in kiwifruit.

Isolation and functional characterization of JcFT, a FLOWERING LOCUS T (FT) homologous gene from the biofuel plant Jatropha curcas

“…To determine whether FT -like genes are functionally conserved and active in vascular tissue, the phloem-specific promoter SUC2 has been used to drive the expression of FT -like genes in Arabidopsis and other species [12,30-32]. We obtained ten WT and eight ft-10 independent T 0 transgenic lines harboring the SUC2:: JcFT construct.…”

“…Although the leaf is generally expected to be the site where a florigen gene is translated into protein [13], many FT -like genes are abundantly expressed in reproductive organs, such as flowers and immature siliques in Arabidopsis [28], flowers and pods in soybean [38], capsules in poplar [37], inflorescence axes in Curcuma kwangsiensis [32], and flowers and berries in grapevine [45]. In the present study, JcFT was mainly expressed in flowers, fruits, and seeds, with the highest expression level in female flowers, suggesting that JcFT may be involved in the development of reproductive organs.…”

Two Subclasses of Differentially Expressed TPS1 Genes and Biochemically Active TPS1 Proteins May Contribute to Sugar Signalling in Kiwifruit Actinidia chinensis

“…A W303-1A wild-type strain carrying the empty pURA3ΔNLS plasmid was used as a positive control, along with tps1 Δ and tps1 Δ tps2 Δ deletion strains complemented with pURA3ΔNLS- ScTPS1 . Yeast transformation was performed as described [48] and positive transformants were selected on synthetic dropout medium lacking uracil and containing 2% (w/v) galactose. For the complementation assay, starter cultures were grown overnight at 28°C while shaking at 200 rev/min in selective minimal medium containing 2% (w/v) galactose.…”

Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time

“…The full-length open reading frame of kiwifruit SVP genes and kiwifruit AGAMOUS ( AG ), FRUITFULL class ( FUL and FUL -like), SEPALLATA class ( SEP1 , SEP3 , and SEP4 ), APETALA3 ( AP3 ), PISTILLATA ( PI ), and CENTRORADIALIS ( CEN ) were amplified and cloned as described previously (Varkonyi-Gasic et al , 2011, 2013; Wu et al , 2012). The bait vector and prey vector were mated and selected on synthetic complete (SC) plates lacking leucine and tryptophan.…”