Ruonala et al. demonstrated that failure of CENL1 down-regulation in PHYA over-expressing poplar prevented growth cessation (and dormancy induction) in a manner similar to over-expression of FT. Incidentally, a near full length putative orthologue of CENL1/TFL (DV121805) was present on the array and was shown to be significantly down-regulated upon transition into endodormancy and through ecodormancy (see supplemental table 7) but was inadvertently left out of Supplemental Table 1. Both CENL1 and FT are likely negatively regulated by MADs box genes related to the DAM genes. Additionally, putative orthologues of both these genes from grape have recently been shown to be down-regulated during endodormancy (see Carmona et al. Plant Mol. Biol. 63:637-650). I would suggest an extension of the hypothesis to include down-regulation of both FT and CENL/TFL like genes by DAM genes play a significant role during endodormancy induction. However, given the primary expression of both DAM and CENL in buds where as FT is primarily expressed in leaves, it seems more likely that a direct negative regulation of CENL/TFL like genes by DAM is primarily responsible for endodormancy induction.
additional thoughts and evidence
23 January 2009
Ruonala et al. demonstrated that failure of CENL1 down-regulation in PHYA over-expressing poplar prevented growth cessation (and dormancy induction) in a manner similar to over-expression of FT. Incidentally, a near full length putative orthologue of CENL1/TFL (DV121805) was present on the array and was shown to be significantly down-regulated upon transition into endodormancy and through ecodormancy (see supplemental table 7) but was inadvertently left out of Supplemental Table 1. Both CENL1 and FT are likely negatively regulated by MADs box genes related to the DAM genes. Additionally, putative orthologues of both these genes from grape have recently been shown to be down-regulated during endodormancy (see Carmona et al. Plant Mol. Biol. 63:637-650). I would suggest an extension of the hypothesis to include down-regulation of both FT and CENL/TFL like genes by DAM genes play a significant role during endodormancy induction. However, given the primary expression of both DAM and CENL in buds where as FT is primarily expressed in leaves, it seems more likely that a direct negative regulation of CENL/TFL like genes by DAM is primarily responsible for endodormancy induction.
Competing interests
None declared