RRC ID 6281
著者 Okada R, Kondo S, Satbhai SB, Yamaguchi N, Tsukuda M, Aoki S.
タイトル Functional characterization of CCA1/LHY homolog genes, PpCCA1a and PpCCA1b, in the moss Physcomitrella patens.
ジャーナル Plant J
Abstract The evolution of circadian clocks in land plants is not understood, because circadian rhythms have received little attention in plants other than angiosperms. We have characterized two genes, PpCCA1a and PpCCA1b, homologs of the Arabidopsis thaliana clock genes CCA1/LHY, from the moss Physcomitrella patens. PpCCA1a and PpCCA1b, together with angiosperm CCA1/LHY homologs, belong to the clock-associated single-myb gene family of green plants (including green algae and land plants). The accumulation of PpCCA1a and PpCCA1b mRNA showed rhythms with a period of approximately 1 day, phased as are those of angiosperm homologs, under 24 h light/dark cycles or in continuous dark. However, in marked contrast to angiosperm homologs, both genes showed arrhythmic profiles in continuous light. The timing of the PpCCA1b peak is determined by the time of the last light to dark transition, suggesting that the arrhythmicity in continuous light is due to dysfunction of the core clock. We generated single and double disruptants for PpCCA1a and PpCCA1b, and found that the double disruptants showed: (i) short periodicity and damped amplitude in the PpCCA1b rhythm, (ii) similar changes in the rhythmically expressed genes PpSIG5 and PpPRRa, and (iii) de-repression of PpCCA1b transcription levels, indicating negative feedback regulation. These observations indicate that the two genes are not merely structural homologs but also functional counterparts of CCA1/LHY. Together, our results illustrate similarities as well as divergence of the clock machineries between P. patens and A. thaliana, two distantly placed species in land plant phylogeny.
巻・号 60(3)
ページ 551-63
公開日 2009-11-1
DOI 10.1111/j.1365-313X.2009.03979.x
PII TPJ3979
PMID 19624471
MeSH Amino Acid Sequence Arabidopsis / chemistry Arabidopsis / genetics Arabidopsis / metabolism Arabidopsis Proteins / chemistry Arabidopsis Proteins / genetics Arabidopsis Proteins / metabolism Bryopsida / chemistry Bryopsida / genetics Bryopsida / metabolism* CLOCK Proteins / chemistry CLOCK Proteins / genetics CLOCK Proteins / metabolism* Circadian Rhythm Conserved Sequence Molecular Sequence Data Phylogeny Sequence Alignment Transcription Factors / chemistry Transcription Factors / genetics Transcription Factors / metabolism Transcription, Genetic
IF 6.141
引用数 30
WOS 分野 PLANT SCIENCES
リソース情報
シロイヌナズナ / 植物培養細胞・遺伝子 pdp21351