Response regulator homologues have complementary, light-dependent functions in the Arabidopsis circadian clock

Circadian clock is usually involved in many physiological processes of plants, including responses to abiotic stress, whilst pseudo-response regulator 7 (PRR7) gene is the main component of the circadian clock. In this study, the cDNA of the PRR7 gene was obtained from trifoliate orange (Poncirus trifoliata). Based on the sequence analysis, the PtPRR7 gene had an open reading frame of 2343 bp, encoded 780 amino acids, and contained proteins of the REC and CCT domains. Subcellular localization indicated that PtPRR7 was mainly localized in the nucleus and a small amount of cytoplasm. qRT-PCR analysis revealed the highest expression level of PtPRR7 in roots than in both shoots and leaves. The PtPRR7 gene during 24 hours of soil water deficit exhibited a circadian rhythmic expression pattern: the expression peak at 9:00 am in leaves and at 21:00 pm in roots. Drought treatment affected PtPRR7 gene expression. Such data provide important references for understanding the characteristics of PtPRR7 gene in citrus plants.

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Expression of the Cytokinin-Induced Type-A Response Regulator GeneARR9Is Regulated by the Circadian Clock inArabidopsis thaliana

Bioscience Biotechnology and Biochemistry ◽

10.1271/bbb.80402 ◽

2008 ◽

Vol 72 (11) ◽

pp. 3025-3029 ◽

Cited By ~ 18

Author(s):

Kai ISHIDA ◽

Takafumi YAMASHINO ◽

Takeshi MIZUNO

Keyword(s):

Circadian Clock ◽

Response Regulator ◽

Type A

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Insight into Missing Genetic Links Between Two Evening-Expressed Pseudo-Response Regulator Genes TOC1 and PRR5 in the Circadian Clock-Controlled Circuitry in Arabidopsis thaliana

Plant and Cell Physiology ◽

10.1093/pcp/pcm178 ◽

2008 ◽

Vol 49 (2) ◽

pp. 201-213 ◽

Cited By ~ 39

Author(s):

Shogo Ito ◽

Yusuke Niwa ◽

Norihito Nakamichi ◽

Hideaki Kawamura ◽

Takafumi Yamashino ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Circadian Clock ◽

Response Regulator ◽

Pseudo Response Regulator ◽

Regulator Genes ◽

Insight Into

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Initial embedding of TRANSPARENT TESTA GLABRA 1 in the Arabidopsis thaliana flowering time regulatory pathway

10.7287/peerj.preprints.27974v1 ◽

2019 ◽

Author(s):

Barbara A M Paffendorf ◽

Rawan Qassrawi ◽

Andrea M Meys ◽

Laura Trimborn ◽

Andrea Schrader

Keyword(s):

Arabidopsis Thaliana ◽

Circadian Clock ◽

Flowering Time ◽

Response Regulator ◽

Regulatory Pathway ◽

In Planta ◽

Transcript Levels ◽

Transparent Testa ◽

Flowering Locus

Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is a pleiotropic regulator that has been predominantly described in its role as a regulator of early accessible developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 are regulators of photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported. Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcription levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92. Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.

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Faculty Opinions recommendation of Post-translational regulation of the Arabidopsis circadian clock through selective proteolysis and phosphorylation of pseudo-response regulator proteins.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1117897.573998 ◽

2008 ◽

Author(s):

Judy Callis

Keyword(s):

Circadian Clock ◽

Translational Regulation ◽

Response Regulator ◽

Pseudo Response Regulator ◽

Selective Proteolysis

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RpaB, Another Response Regulator Operating Circadian Clock-dependent Transcriptional Regulation inSynechococcus elongatusPCC 7942

Journal of Biological Chemistry ◽

10.1074/jbc.m111.338251 ◽

2012 ◽

Vol 287 (31) ◽

pp. 26321-26327 ◽

Cited By ~ 45

Author(s):

Mitsumasa Hanaoka ◽

Naoki Takai ◽

Norimune Hosokawa ◽

Masayuki Fujiwara ◽

Yuki Akimoto ◽

...

Keyword(s):

Transcriptional Regulation ◽

Circadian Clock ◽

Response Regulator

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Circadian control of ORE1 by PRR9 positively regulates leaf senescence in Arabidopsis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1722407115 ◽

2018 ◽

Vol 115 (33) ◽

pp. 8448-8453 ◽

Cited By ~ 38

Author(s):

Hyunmin Kim ◽

Hyo Jung Kim ◽

Quy Thi Vu ◽

Sukjoon Jung ◽

C. Robertson McClung ◽

...

Keyword(s):

Circadian Clock ◽

Leaf Senescence ◽

Posttranscriptional Regulation ◽

Clock Genes ◽

Response Regulator ◽

Early Flowering ◽

Physiological Alterations ◽

Circadian Control ◽

Age Dependent ◽

Pseudo Response Regulator

The circadian clock coordinates the daily cyclic rhythm of numerous biological processes by regulating a large portion of the transcriptome. In animals, the circadian clock is involved in aging and senescence, and circadian disruption by mutations in clock genes frequently accelerates aging. Conversely, aging alters circadian rhythmicity, which causes age-associated physiological alterations. However, interactions between the circadian clock and aging have been rarely studied in plants. Here, we investigated potential roles for the circadian clock in the regulation of leaf senescence in plants. Members of the evening complex in Arabidopsis circadian clock, EARLY FLOWERING 3 (ELF3), EARLY FLOWERING 4 (ELF4), and LUX ARRHYTHMO (LUX), as well as the morning component PSEUDO-RESPONSE REGULATOR 9 (PRR9), affect both age-dependent and dark-induced leaf senescence. The circadian clock regulates the expression of several senescence-related transcription factors. In particular, PRR9 binds directly to the promoter of the positive aging regulator ORESARA1 (ORE1) gene to promote its expression. PRR9 also represses miR164, a posttranscriptional repressor of ORE1. Consistently, genetic analysis revealed that delayed leaf senescence of a prr9 mutant was rescued by ORE1 overexpression. Thus, PRR9, a core circadian component, is a key regulator of leaf senescence via positive regulation of ORE1 through a feed-forward pathway involving posttranscriptional regulation by miR164 and direct transcriptional regulation. Our results indicate that, in plants, the circadian clock and leaf senescence are intimately interwoven as are the clock and aging in animals.

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TRANSPARENT TESTA GLABRA 1 participates in flowering time regulation in Arabidopsis thaliana

PeerJ ◽

10.7717/peerj.8303 ◽

2020 ◽

Vol 8 ◽

pp. e8303 ◽

Cited By ~ 1

Author(s):

Barbara A.M. Paffendorf ◽

Rawan Qassrawi ◽

Andrea M. Meys ◽

Laura Trimborn ◽

Andrea Schrader

Keyword(s):

Arabidopsis Thaliana ◽

Circadian Clock ◽

Flowering Time ◽

Response Regulator ◽

In Planta ◽

Transcript Levels ◽

Autonomous Pathway ◽

Transparent Testa ◽

Flowering Locus

Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is such a factor that has been predominantly described as a regulator of early developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 affect photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported. Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcript levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92. Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.

Download Full-text