Flowering time in a plant is associated often with the property of when the plant flowers. However, this property is dependent on several components of the environment (light, photoperiod and temperature), gene regulation, and several biological processes besides the genetic makeup of the plant. The time taken by the plant to flower also depends on when the vegetative shoot apical meristem transitions into the reproductive shoot apical meristem. The correct timing and perception of the signal are essential to successful flower development in a timely manner. In Arabidopsis, the day length (photoperiod) can control several plant processes including the flowering time. Arabidopsis is a facultative long-day plant since its flowering is promoted by the long days (~16 hours light; 8 hours dark), and delayed, in short-day conditions (8 hours light, 16 hours dark). As compared to rice which is a short-day plant. Flowering in rice is induced by a short day length photoperiod. a17 f74 dbd a5b promotes flowering by acting upstream of CO (CONSTANS), FT (FLOWERING TIME) and SOC1 (SUPPRESSOR OF OVEREXPRESSION OF CO1) EARLY FLOWERING 3 interacts with PHYB FLAVIN-BINDING, KELCH REPEAT, F BOX 1 is clock-controlled and regulates transition to flowering. CIRCADIAN CLOCK ASSOCIATED 1 is a transcriptional repressor and works similar to LHY in a regulatory feedback loop. PHYTOCHROME INTERACTING FACTOR 6 is a Myc-related bHLH transcription factor and physically interacts with TOC1. TIMING OF CAB EXPRESSION 1 is involved in generating circadian rythm and shortens the span of circumnutation rate. TOC1 interacts with ZTL. LATE ELONGATED HYPOCOTYL 1 is a transcription factor involved in circadian rythm along with MYB transcription factor. EARLY FLOWERING 4 controls circadian rhythms and flowering time c72 c72 c72 c72 c72 c72 c72 Found localized to plastid/chloroplast c72 af1 FLOWERING LOCUS C (FLC) is a transcription factor that functions as a repressor of floral transition and contributes to temperature compensation of the circadian clock. Its expression is downregulated during cold treatment. Loss of function of FRIGIDA (FRI) results in early flowering. It is an RNA-binding protein that promotes transition of vegetative meristem to reproductive mesitem and is involved in RNA-mediated chromatin silencing. SPINDLY (SPY) encodes for the enzyme N-acetyl glucosamine transferase that may glycosylate molecules involved in GA signaling. SPY acts as both a repressor of GA responses and as a positive regulation of cytokinin signalling. [imported from TAIR http://arabidopsis.org/servlets/TairObject?id=36698&type=locus] LUMINIDEPENDENS (LD) is a positive regulator of flowering in the autonomous pathway. Its functional disruption results in delayed flowering. This connects to Flower Development Pathway [WP618] The Casein Kinase 2 (CK2) compex has 2 alpha and 2 beta subunits. c72 There are two beta subunits in the complex. However no beta subnuits were found localized to the plastid/chloroplast even though there is an alpha subunit (CK2 alpa Cp) localized to plastid. c72 There are two alpha subunits c72 CK2 complex has 2 alpha subunits and 2 beta subunits. In Arabidopsis, there are 4 genes coding for alpha and 4 for beta subunits. All 8 genes are expressed at the same time, but the proteins are assembled in the complex dynamically. Thus, any of the alpha subunit gene products can get together to form the 2 alpha subunits, along with any any 2 of the beta subunits. regulatory pathway PW:0000004 Pathway Ontology 19121031 PubMed Why does elevated CO2 affect time of flowering? An exploratory study using the photoperiodic flowering mutants of Arabidopsis thaliana. New Phytol 2009 Song X Kristie DN Reekie EG 14978263 PubMed CK2 phosphorylation of CCA1 is necessary for its circadian oscillator function in Arabidopsis. Proc Natl Acad Sci U S A 2004 Daniel X Sugano S Tobin EM 19286557 PubMed A functional genomics approach reveals CHE as a component of the Arabidopsis circadian clock. Science 2009 Pruneda-Paz JL Breton G Para A Kay SA 16926165 PubMed An extensive survey of CK2 alpha and beta subunits in Arabidopsis: multiple isoforms exhibit differential subcellular localization. Plant Cell Physiol 2006 Salinas P Fuentes D Vidal E Jordana X Echeverria M Holuigue L 20202166 PubMed Role of the phytochrome and cryptochrome signaling pathways in hypocotyl phototropism. Plant J 2010 Tsuchida-Mayama T Sakai T Hanada A Uehara Y Asami T Yamaguchi S 19061637 PubMed COP1 and ELF3 control circadian function and photoperiodic flowering by regulating GI stability. Mol Cell 2008 Yu JW Rubio V Lee NY Bai S Lee SY Kim SS Liu L Zhang Y Irigoyen ML Sullivan JA Lee I Xie Q Paek NC Deng XW