Circadian Clock Proteins LHY and CCA1 Regulate SVP Protein Accumulation to Control Flowering in Arabidopsis Export

@article{citeulike:3842563, abstract = {The floral regulators GIGANTEA (GI), CONSTANS (CO), and FLOWERING LOCUS T (FT) play key roles in the photoperiodic flowering responses of the long-day plant Arabidopsis thaliana. The GI-CO-FT pathway is highly conserved in plants. Here, we demonstrate that the circadian clock proteins LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) not only repressed the floral transition under short-day and long-day conditions but also accelerated flowering when the plants were grown under continuous light (LL). LHY and CCA1 accelerated flowering in LL by promoting FT expression through a genetic pathway that appears to be independent of the canonical photoperiodic pathway involving GI and CO proteins. A genetic screen revealed that the late-flowering phenotype of the lhy;cca1 double mutant under LL was suppressed through mutations in SHORT VEGETATIVE PHASE (SVP), a MADS box transcription factor. Yeast two-hybrid analysis demonstrated an interaction between SVP and FLOWERING LOCUS C, and genetic analysis indicated that these two proteins act as partially redundant repressors of flowering time. SVP protein accumulated in lhy;cca1 plants under LL. We propose a model in which LHY and CCA1 accelerate flowering in part by reducing the abundance of SVP and thereby antagonizing its capacity to repress FT expression under LL. 10.1105/tpc.108.061531}, author = {Fujiwara, Sumire and Oda, Atsushi and Yoshida, Riichiro and Niinuma, Kanae and Miyata, Kana and Tomozoe, Yusuke and Tajima, Takeomi and Nakagawa, Mayu and Hayashi, Kounosuke and Coupland, George and Mizoguchi, Tsuyoshi}, citeulike-article-id = {3842563}, citeulike-linkout-0 = {http://dx.doi.org/10.1105/tpc.108.061531}, citeulike-linkout-1 = {http://www.plantcell.org/cgi/content/abstract/20/11/2960?maxtoshow=&HITS=&hits=&RESULTFORMAT=&andorexacttitle=and&titleabstract=MADS&andorexacttitleabs=or&andorexactfulltext=and&searchid=1&usestrictdates=yes&resourcetype=HWCIT&ct}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19011118}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19011118}, doi = {10.1105/tpc.108.061531}, journal = {Plant Cell}, keywords = {cca1, lhy}, month = {November}, number = {11}, pages = {2960--2971}, posted-at = {2009-01-12 13:07:48}, priority = {2}, title = {Circadian Clock Proteins LHY and CCA1 Regulate SVP Protein Accumulation to Control Flowering in Arabidopsis}, url = {http://dx.doi.org/10.1105/tpc.108.061531}, volume = {20}, year = {2008} }

TY - JOUR ID - citeulike:3842563 L3 - citeulike-article-id:3842563 N2 - The floral regulators GIGANTEA (GI), CONSTANS (CO), and FLOWERING LOCUS T (FT) play key roles in the photoperiodic flowering responses of the long-day plant Arabidopsis thaliana. The GI-CO-FT pathway is highly conserved in plants. Here, we demonstrate that the circadian clock proteins LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) not only repressed the floral transition under short-day and long-day conditions but also accelerated flowering when the plants were grown under continuous light (LL). LHY and CCA1 accelerated flowering in LL by promoting FT expression through a genetic pathway that appears to be independent of the canonical photoperiodic pathway involving GI and CO proteins. A genetic screen revealed that the late-flowering phenotype of the lhy;cca1 double mutant under LL was suppressed through mutations in SHORT VEGETATIVE PHASE (SVP), a MADS box transcription factor. Yeast two-hybrid analysis demonstrated an interaction between SVP and FLOWERING LOCUS C, and genetic analysis indicated that these two proteins act as partially redundant repressors of flowering time. SVP protein accumulated in lhy;cca1 plants under LL. We propose a model in which LHY and CCA1 accelerate flowering in part by reducing the abundance of SVP and thereby antagonizing its capacity to repress FT expression under LL. 10.1105/tpc.108.061531 IS - 11 JF - Plant Cell EP - 2971 TI - Circadian Clock Proteins LHY and CCA1 Regulate SVP Protein Accumulation to Control Flowering in Arabidopsis VL - 20 SP - 2960 KW - cca1 KW - lhy AU - Fujiwara, Sumire AU - Oda, Atsushi AU - Yoshida, Riichiro AU - Niinuma, Kanae AU - Miyata, Kana AU - Tomozoe, Yusuke AU - Tajima, Takeomi AU - Nakagawa, Mayu AU - Hayashi, Kounosuke AU - Coupland, George AU - Mizoguchi, Tsuyoshi PY - 2008/11/01/ UR - http://dx.doi.org/10.1105/tpc.108.061531 ER -