Effects of synergistic signaling by phytochrome A and cryptochrome1 on circadian clock-regulated catalase expression.

Zhong, Hai Hong; Resnick, A S; Straume, Martin; McClung, C Robertson

doi:10.1105/tpc.9.6.947

Cited by 85 publications

(83 citation statements)

References 43 publications

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“…3; data not shown). This is interesting because CAT3 mRNA os- cillations damp to constitutively high levels in DD (Zhong et al, 1997). That CAT3 mRNA abundance oscillations damp in DD while transcription continues to oscillate suggests posttranscriptional control in mRNA abundance; either CAT3 mRNA becomes stabilized in DD or CAT3 mRNA abundance is destabilized in the light.…”

Section: Circadian Evening-specific Transcription Of the Cat3 Promotermentioning

confidence: 94%

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Phase-Specific Circadian Clock Regulatory Elements in Arabidopsis

2002

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We have defined a minimal Arabidopsis CATALASE 3 (CAT3) promoter sufficient to drive evening-specific circadian transcription of a LUCIFERASE reporter gene. Deletion analysis and site-directed mutagenesis reveal a circadian response element, the evening element (EE: AAAATATCT), that is necessary for evening-specific transcription. The EE differs only by a single base pair from the CIRCADIAN CLOCK ASSOCIATED 1-binding site (CBS: AAAAAATCT), which is important for morning-specific transcription. We tested the hypothesis that the EE and the CBS specify circadian phase by site-directed mutagenesis to convert the CAT3 EE into a CBS. Changing the CAT3 EE to a CBS changes the phase of peak transcription from the evening to the morning in continuous dark and in light-dark cycles, consistent with the specification of phase by the single base pair that distinguishes these elements. However, rhythmicity of the CBS-containing CAT3 promoter is dramatically compromised in continuous light. Thus, we conclude that additional information normally provided in the context of a morning-specific promoter is necessary for full circadian activity of the CBS.The circadian clock enables an organism to specifically partition aspects of its biology to precise times over the day (Dunlap, 1999). Although the circadian clock is, by definition, endogenous and continues to run in the absence of external time cues, environmental stimuli such as light and temperature act to entrain the internal processes of an organism both to the exact external daily period and in a defined relationship, or phase angle, to the diurnal cycle. For example, in Arabidopsis, light and temperature information are integrated to partition physiological activities such as circadian-regulated leaf movement, stomatal opening, and gene expression to distinct times of day or phases (McClung et al., 2002).A central theme that has emerged in circadian biology is that the core oscillator is composed of a negative feedback loop grounded in positive and negative transcriptional regulation (Dunlap, 1999). It has recently been demonstrated that the Arabidopsis circadian clock entails such a transcriptional feedback loop (Alabadí et al., 2001) that includes at least three components: TIMING OF CAB EXPRESSION 1 (TOC1; also called Arabidopsis PSEUDO-RESPONSE REGULATOR 1, APRR1; Millar et al., 1995;, CIRCADIAN CLOCK ASSOCIATED 1 (CCA1; Wang and Tobin, 1998), and LATE ELON-GATED HYPOCOTYL (LHY; Schaffer et al., 1998).CCA1 and LHY are single-Myb domain transcription factors, and DNA-binding activity of CCA1 to a CCA1-binding site (CBS: AAAAATCT) has been characterized (Wang et al., 1997). The hypothesized role of TOC1 as a transcription factor is based on similarity to CONSTANS, although DNA binding by TOC1 has not been experimentally established (Strayer et al., 2000). However, TOC1 (APRR1) has been shown to bind to PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), a Myc-related basic helix-loop-helix transcription factor, and to the related PIF3-LIKE 1 (PIL1; Makino et al., 2002). Expression o...

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Section: Circadian Evening-specific Transcription Of the Cat3 Promotermentioning

confidence: 94%

“…Rhythms were analyzed by fast Fourier transform-nonlinear least squares analysis (Plautz et al, 1997;Zhong et al, 1997). Except in Figure 1, all data were normalized to the average luciferase activity of the individual seedling and are presented as relative bioluminescence.…”

Section: Discussionmentioning

confidence: 99%

Phase-Specific Circadian Clock Regulatory Elements in Arabidopsis

2002

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“…Statistical analysis of the time series data by fast Fourier transformnonlinear least squares (FFT-NLLS) (see "Materials and Methods"; see also Plautz et al, 1997;Zhong et al, 1997) detected significant circadian oscillations in both SHM1 and SHM4 mRNA abundance. The period lengths (mean Ϯ sd) of the oscillations were 26.0 Ϯ 2.1 h for SHM1 and 23.8 Ϯ 1.2 h for SHM4.…”

Section: Circadian Regulation Of Shm1 and Shm4 Mrna Abundancementioning

confidence: 99%

“…For evaluation of circadian rhythmicity, time series data were quantitatively evaluated by an iterative, coupled FFT-NLLS multicomponent cosine estimation algorithm as previously described (Plautz et al, 1997;Zhong et al, 1997). FFT-NLLS provides estimates of periods, phases, and amplitudes of rhythmic components, along with associated estimates of joint parameter confidence limits and of the statistical significance of rhythmic amplitudes.…”

Section: Rna Preparation and Analysismentioning

confidence: 99%

Integrated Temporal Regulation of the Photorespiratory Pathway. Circadian Regulation of Two Arabidopsis Genes Encoding Serine Hydroxymethyltransferase

et al. 2000

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The photorespiratory pathway is comprised of enzymes localized within three distinct cellular compartments: chloroplasts, peroxisomes, and mitochondria. Photorespiratory enzymes are encoded by nuclear genes, translated in the cytosol, and targeted into these distinct subcellular compartments. One likely means by which to regulate the expression of the genes encoding photorespiratory enzymes is coordinated temporal control. We have previously shown in Arabidopsis that a circadian clock regulates the expression of the nuclear genes encoding both chloroplastic (Rubisco small subunit and Rubisco activase) and peroxisomal (catalase) components of the photorespiratory pathway. To determine whether a circadian clock also regulates the expression of genes encoding mitochondrial components of the photorespiratory pathway, we characterized a family of Arabidopsis serine hydroxymethyltransferase (SHM) genes. We examined mRNA accumulation for two of these family members, including one probable photorespiratory gene (SHM1) and a second gene expressed maximally in roots (SHM4), and show that both exhibit circadian oscillations in mRNA abundance that are in phase with those described for other photorespiratory genes. In addition, we show that SHM1 mRNA accumulates in light-grown seedlings, although this response is probably an indirect consequence of the induction of photosynthesis and photorespiration by illumination.

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“…It is not surprising that light is the most important regulatory cue for the entrainment and activity of the circadian clock, because in addition to providing energy for photosynthesis, light also affects many other environmental conditions such as temperature and water availability (McClung, 2001). The role of cryptochromes in regulation of the plant circadian clock was indicated by the observation that the Arabidopsis hy1 mutant impaired in the synthesis of phytochrome chromophore showed little effect in the blue light regulation of circadian rhythms of CAB promoter activity (Millar et al, 1995), and that the Arabidopsis cry1 mutant significantly affected the circadian rhythm of the expression of a catalase gene (Zhong et al, 1997).…”

Section: Functions Of Arabidopsis Cryptochromes In Regulating the Cirmentioning

confidence: 99%