Circadian Stress Regimes Affect the Circadian Clock and Cause Jasmonic Acid-Dependent Cell Death in Cytokinin-Deficient Arabidopsis Plants
The circadian clock helps plants measure daylength and adapt to changes in the day-night rhythm. We found that changes in the light-dark regime triggered stress responses, eventually leading to cell death, in leaves of Arabidopsis thaliana plants with reduced cytokinin levels or defective cytokinin...
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Published in | The Plant cell Vol. 28; no. 7; pp. 1616 - 1639 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society of Plant Biologists
01.07.2016
American Society of Plant Biologists (ASPB) |
Subjects | |
Online Access | Get full text |
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Summary: | The circadian clock helps plants measure daylength and adapt to changes in the day-night rhythm. We found that changes in the light-dark regime triggered stress responses, eventually leading to cell death, in leaves of Arabidopsis thaliana plants with reduced cytokinin levels or defective cytokinin signaling. Prolonged light treatment followed by a dark period induced stress and cell death marker genes while reducing photosynthetic efficiency. This response, called circadian stress, is also characterized by altered expression of clock and clock output genes. In particular, this treatment strongly reduced the expression of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY). Intriguingly, similar changes in gene expression and cell death were observed in clock mutants lacking proper CCA1 and LHY function. Circadian stress caused strong changes in reactive oxygen species- and jasmonic acid (JA)-related gene expression. The activation of the JA pathway, involving the accumulation of JA metabolites, was crucial for the induction of cell death, since the cell death phenotype was strongly reduced in the jasmonate resistant1 mutant background. We propose that adaptation to circadian stress regimes requires a normal cytokinin status which, acting primarily through the AHK3 receptor, supports circadian clock function to guard against the detrimental effects of circadian stress. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 PMCID: PMC4981127 www.plantcell.org/cgi/doi/10.1105/tpc.16.00016 The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is: Thomas Schmülling (thomas.schmuelling@fu-berlin.de). |
ISSN: | 1040-4651 1532-298X |
DOI: | 10.1105/tpc.16.00016 |