From a repressilator-based circadian clock mechanism to an external coincidence model responsible for photoperiod and temperature control of plant architecture in Arabodopsis thaliana.
Biosci Biotechnol Biochem
; 77(1): 10-6, 2013.
Article
em En
| MEDLINE
| ID: mdl-23291766
ABSTRACT
Circadian clocks enable organisms to define subjective time, that is, to anticipate diurnal day and night cycles. Endogenous circadian rhythms regulate many aspects of an organism's physiological and morphological growth and development. These daily oscillations are synchronized to the environment by external cues such as light and temperature, resulting in enhanced fitness and growth vigor in plants. Recent findings concerning biochemical properties of central oscillators in Arabidopsis thaliana have advanced our understanding of circadian clock function. Central oscillators are composed of three classes of transcriptional repressors. The interactions among them include a repressilator structure. Output from the circadian clock is transduced through regulating transcription of downstream genes directly by the oscillator components. The essential role of the output pathway in the circadian system is to make different elementary steps responsible for daily cellular processes exert maximum effects at specific times of the day. Recently, significant progress was made in defining the mechanisms by which plant growth on a day-to-day basis is activated at specific times of the day in a manner dependent on photoperiod and temperature conditions. Plant growth is controlled by the clock through interactions with light and phytohormone signaling. This review focuses on the node that connects clock output to light and phytohormone signaling that coordinates plant growth with rhythmic changes in the environment.
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Base de dados:
MEDLINE
Assunto principal:
Arabidopsis
/
Regulação da Expressão Gênica de Plantas
/
Proteínas de Arabidopsis
/
Fatores de Transcrição Hélice-Alça-Hélice Básicos
/
Relógios Circadianos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article