Winter disruption of the circadian clock in chestnut

doi:10.1073/pnas.0408549102

Winter disruption of the circadian clock in chestnut

Departamento de Biotecnología, Escuela Técnica Superior de Ingenieros de Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, E-28040 Madrid, Spain

Edited by Michael Rosbash, Brandeis University, Waltham, MA, and approved March 28, 2005 (received for review November 17, 2004)

Abstract

Circadian clock performance during winter dormancy has been investigated in chestnut by using as marker genes CsTOC1 and CsLHY, which are homologous to essential components of the central circadian oscillator in Arabidopsis. During vegetative growth, mRNA levels of these two genes in chestnut seedlings and adult plants cycled daily, as expected. However, during winter dormancy, CsTOC1 and CsLHY mRNA levels were high and did not oscillate, indicating that the circadian clock was altered. A similar disruption was induced by chilling chestnut seedlings (to 4°C). Normal cycling resumed when endodormant or cold-treated plants were returned to 22°C. The behavior of CsTOC1 and CsLHY during a cold response reveals a relevant aspect of clock regulation not yet encountered in Arabidopsis.

Footnotes

↵ † To whom correspondence should be addressed. E-mail: isabel.allona{at}upm.es.
↵ * C.A. and I.A. contributed equally to this work.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations: SD, short day; LD, long day; LL, continuous light; PRR, pseudoresponse regulator.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database [accession nos. AY611028 (CsTOC1) and AY611029 (CsLHY)].