High impact information on LFY

• Floral meristem identity genes LEAFY (LFY) and APETALA1 (AP1) promote establishment and maintenance of floral identity in newly formed floral primordia [1].
• We present evidence that AGL24 is an early target of transcriptional repression by LFY and AP1 [1].
• FT, together with LFY, promotes flowering and is positively regulated by CO [2].
• A photoperiod-dependent pathway relays signals from photoreceptors to a transcription factor gene, CONSTANS (CO), which activates downstream meristem identity genes such as LEAFY (LFY) [2].
• Elevated AGL19 levels activate LFY and AP1 and eventually cause flowering [3].

Biological context of LFY

• The floral meristem identity gene LEAFY (LFY) plays a role in the initiation phase through at least two pathways, which differ from each other in the involvement of two homeotic genes, APETALA3 (AP3) and PISTILLATA (PI) [4].
• To distinguish regulatory versus functional changes within the LcrLFY locus, reciprocal chimeric transgenes between LcrLFY and LFY were constructed [5].
• Experiments using a steroid-inducible form of LFY show that, in contrast to its direct transcriptional activation of other floral homeotic genes, LFY acts in both a direct and an indirect manner to regulate AP3 expression [6].
• Among 29 Brassicaceae species, several other motifs, but not the LFY and WUS binding sites identified previously, are largely invariant [7].
• Here we show that the additional LFY targets include the APETALA1-related factor, CAULIFLOWER, as well as three transcription factors and two putative signal transduction pathway components [8].

Anatomical context of LFY

• This suggests that, unlike FLO and LFY, which specify determinacy only during floral development, the NFL genes act to specify determinacy in the progenitor cells for both flowers and leaves [9].
• We have identified two FLO/LFY genes, PpLFY1 and PpLFY2, that regulate the first cell division after formation of the zygote in the moss Physcomitrella patens [10].

Associations of LFY with chemical compounds

• As expected, reporter activity in a pattern typical for the LFY promoter was ethanol dependent [11].

Regulatory relationships of LFY

• AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes [12].
• Double mutants between ft-1 or fwa-1 and lfy-6 completely lack flowerlike structures, indicating that both FWA and FT act redundantly with LFY to control AP1 [13].
• LMI1 acts together with LFY to activate CAL expression [14].

Other interactions of LFY

• We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract [15].
• In contrast, the coding regions of TFL1 and LFY display a significant reduction in nucleotide variation, suggesting that these sequences have been subjected to a recent adaptive sweep [16].
• Since phyB did not change the GA responsiveness of the LFY promoter and suppressed the lack of flowering of severe GA-deficient mutants under short days, we propose that PHYB modulates flowering time at least partially through a GA-independent pathway [17].
• Here we describe Impatiens homologues of LFY, TFL1 and AG (IbLFY, IbTFL1 and IbAG) that are highly conserved at a sequence level and demonstrate homologous functions when expressed ectopically in transgenic Arabidopsis [18].
• In Arabidopsis, several genetic pathways controlling the floral transition (flowering) are integrated at the transcriptional regulation of FT, LFY and SOC1 [19].

Analytical, diagnostic and therapeutic context of LFY

• To test this, we monitored the gene expression changes that occur in tissue culture after activation of LFY using a flower-specific cDNA microarray [20].
• Furthermore, in situ hybridization analysis indicates that LFY levels are drastically reduced at the apex of ld ap1 cal plants after bolting [21].
• This protocol coupling with single-cell reverse transcriptase-polymerase chain reaction (SC-RT-PCR) has been used to monitor LFY and AP2 expression in individual cells from the shoot apical meristem, leaf, root, and stem of Arabidopsis, simultaneously [22].
• For the genus Ophrys L. (Orchidaceae), the LFY/FLO gene contains an intron of 2 kb size and is the most useful marker identified, useful even within close related species complex, where other classic genes (ITS, cpDNA genes, etc.) are useless [Ref].

References