Abstract
The diurnal expression of two newly isolated genes, ccr and clr, was studied in Duncan grapefruits (Citrus paradisi). The steady-state levels of mRNA corresponding to each of the genes reach their maximum at different time points during the day. The peak of ccr accumulation is at the end of the light period, while accumulation of mRNA corresponding to clr peaks already after 4–6 hours of light. The lowest steady-state levels of mRNA corresponding to both of the genes is at the dark period, ccr is highly homologous to lirl, a gene recently isolated from rice. Comparison of the deduced amino acid sequence of ccr to that deduced from lirl indicates 49% of identity. The deduced proteins contain two imperfect repeats with two cystein residues that are positionally conserved in each of the repeats. The steady-state level of ccr transcripts continues to oscillate after the plants are transferred to darkness and displays a circadian rhythm similar to that of lirl. On the other hand, the level of clr transcripts is almost undetectable after more than 12 h in the dark. Artificial light supplement in the dark extends the length of time of clr expression during the day. clr does not show significant homology to any of the known circadian or light-regulated genes.
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References
Anderson CM, Wilkins MB: Period and phase control by temperature in the circadian rhythm of carbon dioxide fixation in illuminated leaves of Bryophyllum fedtschenkoi. Planta 177: 456–469 (1989).
Aschoff J: Circadian Clocks. North-Holland, Amsterdam (1965).
Bunning E: Endogenous rhythms in plants. Annu Rev Plant Physiol 7: 71–90 (1956).
Cumming BG, Wagner E: Rhythmic processes in plants. Annu Rev Plant Physiol 19: 381–416 (1968).
Gagne G, Guerin M: The early genetic response to light in the green unicellular alga Chlamydomonas eugametos grown under light/dark cycles involves genes that represent direct responses to light and photosynthesis. Plant Mol Biol 18: 429–445 (1992).
Giuliano G, Hoffman NE, Ko K, Scolnik PA, Cashmore AR: A light-entrained circadian clock controls transcription of several plant genes. EMBO J 7: 3635–3642 (1988).
Gorton HL, Williams WE, Assmann SM: Circadian rhythms in stomatal responsiveness to red and blue light. Plant Physiol 103: 399–406 (1993).
Kloppstech K: Diurnal and circadian rhythmycity in the expression of light-induced plant nuclear messenger RNA. Planta 165: 502–506 (1985).
Nagy F, Kay SA, Chua N-H: A circadian clock regulates transcription of the wheat Cab-I gene. Genes Devel 2: 376–382 (1988).
Piechulla B: Changes of the diurnal and circadian (endogenous) mRNA oscillations of the chlorophyll a/b binding protein in tomato leaves during altered day/night (light/dark) regimes. Plant Mol Biol 12: 317–327 (1989).
Piechulla B, Gruissem W: Diurnal mRNA fluctuation of nuclear and plastid genes in developing tomato fruits. EMBO J 6: 3596–3599 (1987).
Reimmann C, Dudler R: Circadian rhytmicity in the expression of a novel light-regulated rice gene. Plant Mol Biol 22: 165–170 (1993).
Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY (1989).
Sanger F, Nicklen S, Coulson AR: DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74: 5463–5467 (1977).
Spiller SC, Kaufman LS, Thompson WF, Briggs WR: Specific mRNA and rRNA levels in greening pea leaves during recovery from iron stress. Plant Physiol 84: 409–414 (1987).
Sweeney BM: Rhythmic Phenomena in Plants. Academic Press, San Diego., FL (1987).
Vince-Pruce D: Photoperiodism in Plants. McGraw-Hill, London (1975).
Watillon B, Kettmann R, Boxus P, Burny A: Developmental and circadian pattern of rubisco activase mRNA accumulation in apple plants. Plant Mol Biol 23: 501–509 (1993).
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Abied, M.A., Holland, D. Two newly isolated genes from citrus exhibit a different pattern of diurnal expression and light response. Plant Mol Biol 26, 165–173 (1994). https://doi.org/10.1007/BF00039529
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DOI: https://doi.org/10.1007/BF00039529