The circadian clock gates expression of two Arabidopsis catalase genes to distinct and opposite circadian phases

• Published in: Molecular & general genetics Vol. 251; no. 2; p. 196
• Main Authors: Zhong, H.H, McClung, C.R. (Dartmouth Coll., Hanover, New Hampshire (USA). Dept. of Biological Sciences)
• Format: Journal Article
• Language: English
• Published: Germany 23.05.1996
• Subjects: Amino Acid Sequence; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins; ARABIDOPSIS THALIANA; Base Sequence; BIOLOGICAL RHYTHMS; CATALASA; CATALASE; Catalase - genetics; Circadian Rhythm; DNA Primers; EXPRESION GENICA; EXPRESSION DES GENES; GENE; GENE EXPRESSION; Gene Expression Regulation, Plant; GENES; Light; Molecular Sequence Data; Plant Proteins; Plants; RITMOS BIOLOGICOS; RYTHME BIOLOGIQUE; Transcription, Genetic
• ISSN: 0026-8925; 1432-1874
• DOI: 10.1007/s004380050157

In Arabidopsis thaliana, catalase is encoded by a small gene family. We have characterized cDNA and genomic clones containing the Arabidopsis catalase gene CAT3, present as a single copy in the nuclear genome. Six introns were identified in the CAT3 coding region and two transcription start sites have been been mapped by primer extension. The deduced amino acid sequence of CAT3 is highly similar to other catalases. CAT3 expression is similar in seedlings germinated and grown either in continuous light or in continuous dark, suggesting that CAT3 expression in seedlings is not light responsive. CAT3 expression is controlled by the circadian clock; in 5-week-old plants grown on a light-dark cycle and then transferred to continuous light, robust oscillations in CAT3 mRNA abundance with circadian period persist for at least five circadian cycles. Interestingly, the peak in CAT3 mRNA abundance occurs in the subjective evening, which is out of phase with expression of the Arabidopsis CAT2 catalase gene, which shows clock-regulated expression gated to the subjective early morning.