The complex regulation of ferredoxin/thioredoxin-related genes by light and the circadian clock

Lemaire, Stéphane D.; Stein, Mariana; Issakidis‐Bourguet, Emmanuelle; Kéryer, Eliane; Benoit, Vanina; Pineau, Bernard; Gérard-Hirne, Catherine; Miginiac‐Maslow, Myroslawa; Jacquot, Jean‐Pierre

doi:10.1007/s004250050626

Cited by 39 publications

(29 citation statements)

References 50 publications

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“…FNR is a ubiquitous flavoenzyme that oxidizes the final reduced product of the photosynthetic electron transport chain, ferredoxin (Fd), to reduce NADP + , resulting in ATP production. Therefore, FNR levels (activity) regulate cellular NADPH/NADP + and ATP/AMP ratios (16,22). Consistent with LN induction of FNR1 expression, we detected higher NADPH/NADP + and lower AMP/ATP ratios in WT plants in LN conditions than in NN conditions (P < 0.05).…”

Section: Resultssupporting

confidence: 80%

“…These results suggest that CRY1 may work downstream of FNR1 in the N-signaling pathway. Although previous studies reported that both the fnr2 mutant (16,22) and the cry2 mutant (19, 23) had a late-flowering phenotype, here these mutants exhibited normal responses to N changes (P < 0.05; SI Appendix, Table S3), suggesting that neither FNR2 nor CRY2 plays an essential role in N-regulated flowering time.…”

Section: Resultscontrasting

confidence: 74%

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Arabidopsis cryptochrome 1 functions in nitrogen regulation of flowering

Yuan

Zhang

Zheng

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

115

103

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The phenomenon of delayed flowering after the application of nitrogen (N) fertilizer has long been known in agriculture, but the detailed molecular basis for this phenomenon is largely unclear. Here we used a modified method of suppression-subtractive hybridization to identify two key factors involved in N-regulated flowering time control in Arabidopsis thaliana, namely ferredoxin-NADP + -oxidoreductase and the blue-light receptor cryptochrome 1 (CRY1). The expression of both genes is induced by low N levels, and their loss-offunction mutants are insensitive to altered N concentration. Low-N conditions increase both NADPH/NADP + and ATP/AMP ratios, which in turn affect adenosine monophosphate-activated protein kinase (AMPK) activity. Moreover, our results show that the AMPK activity and nuclear localization are rhythmic and inversely correlated with nuclear CRY1 protein abundance. Low-N conditions increase but high-N conditions decrease the expression of several key components of the central oscillator (e.g., CCA1, LHY, and TOC1) and the flowering output genes (e.g., GI and CO). Taken together, our results suggest that N signaling functions as a modulator of nuclear CRY1 protein abundance, as well as the input signal for the central circadian clock to interfere with the normal flowering process. T he transition from vegetative to reproductive development is a central event in the plant life cycle, which is coordinately regulated by various endogenous and external cues. In the model dicotyledonous plant species Arabidopsis thaliana, five distinct genetic pathways regulating flowering time have been established: the vernalization pathway, photoperiod pathway, gibberellin acid (GA) pathway, autonomous pathway, and endogenous (age) pathway (1). These pathways ultimately converge to regulate a set of floral integrator genes, FLOWERING LOCUS T (FT) and SUPPRESSOR OF CONSTANS 1 (SOC1), which in turn activate the expression of floral meristem identity genes to trigger the formation of flowers (2-4).Plants use the circadian clock as the timekeeping mechanism to measure day length and to ensure flowering at the proper season (5, 6). As a facultative long-day (LD) plant, Arabidopsis flowers earlier under LD conditions than under short-day (SD) conditions. Forward genetics in A. thaliana have identified the GI-CO-FT hierarchy as the canonical genetic pathway promoting flowering specifically under LD conditions (5,7,8). In this pathway, GI (GIGANTEA) can be considered the output point of the circadian clock to control flowering by regulating CONSTANS (CO) expression in the right phase, which activates expression of FT and TSF (TWIN SISTER OF FT) in the companion cells of the phloem within the vascular tissue (2, 9). FT and TSF proteins act as the long-sought florigens that move from leaves to the apical meristem to induce genes required for reproductive development (2-4). Both GI and CO are regulated by the circadian clock and by light signaling simultaneously and at both transcriptional and posttranscriptional levels, to en...

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Section: Resultssupporting

confidence: 80%

Section: Resultscontrasting

confidence: 74%

Arabidopsis cryptochrome 1 functions in nitrogen regulation of flowering

Yuan

Zhang

Zheng

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

115

103

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“…In plants, over 12% of the genes of Arabidopsis, including AGPase genes, are known to encode transcripts displaying circadian oscillations (Harmer et al, 2000). However, previous experiments investigating the abundance of several different transcripts in Chlamydomonas demonstrated that transcript abundance rhythms were not necessarily followed by similar modifications in protein amount or activities (Lemaire et al, 1999(Lemaire et al, , 2002Gibon et al, 2004). To explain the rhythmicity detected in AGPase activity, a quantitative assessment using an antibody raised against the small subunit of AGPase (kindly provided by C. Hannah) in western-blot experiments was performed (Fig.…”

Section: Starch Synthesis Is Tightly Correlated To Adp-glc Pyrophosphmentioning

confidence: 99%

Circadian Clock Regulation of Starch Metabolism Establishes GBSSI as a Major Contributor to Amylopectin Synthesis in Chlamydomonas reinhardtii

et al. 2006

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Chlamydomonas reinhardtii displays a diurnal rhythm of starch content that peaks in the middle of the night phase if the algae are provided with acetate and CO 2 as a carbon source. We show that this rhythm is controlled by the circadian clock and is tightly correlated to ADP-glucose pyrophosphorylase activity. Persistence of this rhythm depends on the presence of either soluble starch synthase III or granule-bound starch synthase I (GBSSI). We show that both enzymes play a similar function in synthesizing the long glucan fraction that interconnects the amylopectin clusters. We demonstrate that in log phase-oscillating cultures, GBSSI is required to obtain maximal polysaccharide content and fully compensates for the loss of soluble starch synthase III. A point mutation in the GBSSI gene that prevents extension of amylopectin chains, but retains the enzyme's normal ability to extend maltooligosaccharides, abolishes the function of GBSSI both in amylopectin and amylose synthesis and leads to a decrease in starch content in oscillating cultures. We propose that GBSSI has evolved as a major enzyme of amylopectin synthesis and that amylose synthesis comes as a secondary consequence of prolonged synthesis by GBSSI in arrhythmic systems. Maintenance in higher plant leaves of circadian clock control of GBSSI transcription is discussed.

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“…Thioredoxin h is discussed to contribute to a light-dependent long-distance thiol signal being generated in leaves and thereby connecting metabolic processes in sink organs with photosynthetic activity in source organs (Balmer et al, 2006). Thioredoxin h is also discussed to play a role in circadian clock regulation and is shown to be light induced (Lemaire et al, 1999(Lemaire et al, , 2002.…”

Section: Redox Control In Mature Sieve Elementsmentioning

confidence: 99%

Transport and Sorting of the Solanum tuberosum Sucrose Transporter SUT1 Is Affected by Posttranslational Modification

et al. 2008

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The plant sucrose transporter SUT1 from Solanum tuberosum revealed a dramatic redox-dependent increase in sucrose transport activity when heterologously expressed in Saccharomyces cerevisiae. Plant plasma membrane vesicles do not show any change in proton flux across the plasma membrane in the presence of redox reagents, indicating a SUT1-specific effect of redox reagents. Redox-dependent sucrose transport activity was confirmed electrophysiologically in Xenopus laevis oocytes with SUT1 from maize (Zea mays). Localization studies of green fluorescent protein fusion constructs showed that an oxidative environment increased the targeting of SUT1 to the plasma membrane where the protein concentrates in 200-to 300-nm raft-like microdomains. Using plant plasma membranes, St SUT1 can be detected in the detergent-resistant membrane fraction. Importantly, in yeast and in plants, oxidative reagents induced a shift in the monomer to dimer equilibrium of the St SUT1 protein and increased the fraction of dimer. Biochemical methods confirmed the capacity of SUT1 to form a dimer in plants and yeast cells in a redox-dependent manner. Blue native PAGE, chemical cross-linking, and immunoprecipitation, as well as the analysis of transgenic plants with reduced expression of St SUT1, confirmed the dimerization of St SUT1 and Sl SUT1 (from Solanum lycopersicum) in planta. The ability to form homodimers in plant cells was analyzed by the split yellow fluorescent protein technique in transiently transformed tobacco (Nicotiana tabacum) leaves and protoplasts. Oligomerization seems to be cell type specific since under native-like conditions, a phloem-specific reduction of the dimeric form of the St SUT1 protein was detectable in SUT1 antisense plants, whereas constitutively inhibited antisense plants showed reduction only of the monomeric form. The role of redox control of sucrose transport in plants is discussed.

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The complex regulation of ferredoxin/thioredoxin-related genes by light and the circadian clock

Cited by 39 publications

References 50 publications

Arabidopsis cryptochrome 1 functions in nitrogen regulation of flowering

Arabidopsis cryptochrome 1 functions in nitrogen regulation of flowering

Circadian Clock Regulation of Starch Metabolism Establishes GBSSI as a Major Contributor to Amylopectin Synthesis in Chlamydomonas reinhardtii

Transport and Sorting of the Solanum tuberosum Sucrose Transporter SUT1 Is Affected by Posttranslational Modification

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