scholarly journals Time Lag Between Light and Heat Diurnal Cycles Modulates CIRCADIAN CLOCK ASSOCIATION 1 Rhythm and Growth in Arabidopsis thaliana

2021 ◽  
Vol 11 ◽  
Author(s):  
Kosaku Masuda ◽  
Tatsuya Yamada ◽  
Yuya Kagawa ◽  
Hirokazu Fukuda
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Rhythms ◽  
Plant Growth ◽  
Circadian Clock ◽  
Time Lag ◽  
Luciferase Reporter ◽  
Time Lags ◽  
Light Cycle ◽  
Growth Responses ◽  
Diurnal Cycles

Plant growth responses to cues such as light, temperature, and humidity enable the entrainment of the circadian rhythms with diurnal cycles. For example, the temperature variations between day and night affect plant growth and accompany the time lag to light cycle. Despite its importance, there has been no systematic investigation into time lags, and the mechanisms behind the entrainment of the circadian rhythms with multiple cycles remain unknown. Here, we investigated systemically the effects of the time lag on the circadian rhythm and growth in Arabidopsis thaliana. To investigate the entrainment status of the circadian clock, the rhythm of the clock gene CIRCADIAN CLOCK ASSOCIATION 1 (CCA1) was measured with a luciferase reporter assay. As a result, the rhythm was significantly modulated by the time lag with +10°C heating for 4 h every day but not −10°C cooling. A model based on coupled cellular oscillators successfully described these rhythm modulations. In addition, seedling growth depended on the time lag of the heating cycle but not that of the cooling cycle. Based on the relationship between the CCA1 rhythms and growth, we established an estimation method for the effects of the time lag. Our results found that plant growth relates to the CCA1 rhythm and provides a method by which to estimate the appropriate combination of light–dark and temperature cycles.

scholarly journals A Genome-wide microRNA screen identifies the microRNA-183/96/182 cluster as a modulator of circadian rhythms

2020 ◽  
Author(s):  
Lili Zhou ◽  
Caitlyn Miller ◽  
Loren J. Miraglia ◽  
Angelica Romero ◽  
Ludovic S. Mure ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Luciferase Reporter ◽  
Regulatory Function ◽  
Mirna Cluster ◽  
Dependent Manner ◽  
Genome Wide ◽  
A Genome

AbstractThe regulatory mechanisms of circadian rhythms have been studied primarily at the level of the transcription-translation feedback loops of protein coding genes. Regulatory modules involving non-coding RNAs are less thoroughly understood. In particular, emerging evidence has revealed the important role of miRNAs in maintaining the robustness of the circadian system. To identify miRNAs that have the potential to modulate circadian rhythms, we conducted a genome-wide miRNA screen using U2OS luciferase reporter cells. Among 989 miRNAs in the library, 120 changed the period length in a dosage-dependent manner. We further validated the circadian regulatory function of a miRNA cluster, miR-183/96/182, both in vitro and in vivo. We found that all three members of this miRNA cluster can modulate circadian rhythms. Particularly, miR-96 directly targeted a core circadian clock gene, PER2. The knockout of the miR-183/96/182 cluster in mice showed tissue-specific effects on circadian parameters and altered circadian rhythms at the behavioral level. This study identified a large number of miRNAs, including the miR-183/96/182 cluster, as circadian modulators. We provide a resource for further understanding the role of miRNAs in the circadian network and highlight the importance of miRNAs as a novel genome-wide layer of circadian clock regulation.Significance StatementAlthough miRNAs are emerging as important regulators of diverse physiological and pathological processes, our knowledge of their potential role in regulation of circadian rhythms is still limited. We deployed a cell-based genome-wide screening approach, and successfully identified mature miRNAs as cell-autonomous circadian modulators. We then specifically focused on the miR-183/96/182 cluster among the candidate miRNA hits and revealed their circadian function both in vitro and in vivo from the unbiased screen. This study provides resources for further understanding the role of miRNAs in the circadian network. It also highlights the importance of miRNAs as a novel genome-wide layer of circadian clock regulation.

scholarly journals A genome-wide microRNA screen identifies the microRNA-183/96/182 cluster as a modulator of circadian rhythms

2020 ◽  
Vol 118 (1) ◽  
pp. e2020454118
Author(s):  
Lili Zhou ◽  
Caitlyn Miller ◽  
Loren J. Miraglia ◽  
Angelica Romero ◽  
Ludovic S. Mure ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Luciferase Reporter ◽  
Regulatory Function ◽  
Mirna Cluster ◽  
Dependent Manner ◽  
Genome Wide ◽  
A Genome

The regulatory mechanisms of circadian rhythms have been studied primarily at the level of the transcription–translation feedback loops of protein-coding genes. Regulatory modules involving noncoding RNAs are less thoroughly understood. In particular, emerging evidence has revealed the important role of microRNAs (miRNAs) in maintaining the robustness of the circadian system. To identify miRNAs that have the potential to modulate circadian rhythms, we conducted a genome-wide miRNA screen using U2OS luciferase reporter cells. Among 989 miRNAs in the library, 120 changed the period length in a dose-dependent manner. We further validated the circadian regulatory function of an miRNA cluster, miR-183/96/182, both in vitro and in vivo. We found that all three members of this miRNA cluster can modulate circadian rhythms. Particularly, miR-96 directly targeted a core circadian clock gene, PER2. The knockout of the miR-183/96/182 cluster in mice showed tissue-specific effects on circadian parameters and altered circadian rhythms at the behavioral level. This study identified a large number of miRNAs, including the miR-183/96/182 cluster, as circadian modulators. We provide a resource for further understanding the role of miRNAs in the circadian network and highlight the importance of miRNAs as a genome-wide layer of circadian clock regulation.

scholarly journals A GATA Transcription Factor from Soybean (Glycine max) Regulates Chlorophyll Biosynthesis and Suppresses Growth in the Transgenic Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1036 ◽  
Author(s):  
Chanjuan Zhang ◽  
Yi Huang ◽  
Zhiyuan Xiao ◽  
Hongli Yang ◽  
Qingnan Hao ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Glycine Max ◽  
Plant Growth ◽  
Transgenic Arabidopsis ◽  
Higher Plants ◽  
Chlorophyll Biosynthesis ◽  
Growth And Yield ◽  
Luciferase Reporter ◽  
Gata Transcription Factor ◽  
Dual Luciferase Reporter Assay

Chlorophyll plays an essential role in photosynthetic light harvesting and energy transduction in green tissues of higher plants and is closely related to photosynthesis and crop yield. Identification of transcription factors (TFs) involved in regulating chlorophyll biosynthesis is still limited in soybean (Glycine max), and the previously identified GmGATA58 is suggested to potentially modulate chlorophyll and nitrogen metabolisms, but its complete function is still unknown. In this study, subcellular localization assay showed that GmGATA58 was localized in the nucleus. Histochemical GUS assay and qPCR assay indicated that GmGATA58 was mainly expressed in leaves and responded to nitrogen, light and phytohormone treatments. Overexpression of GmGATA58 in the Arabidopsis thaliana ortholog AtGATA21 (gnc) mutant complemented the greening defect, while overexpression in Arabidopsis wild-type led to increasing chlorophyll content in leaves through up-regulating the expression levels of the large of chlorophyll biosynthetic pathway genes, but suppressing plant growth and yield, although the net photosynthetic rate was slightly improved. Dual-luciferase reporter assay also supported that GmGATA58 activated the transcription activities of three promoters of key chlorophyll biosynthetic genes of soybean in transformed protoplast of Arabidopsis. It is concluded that GmGATA58 played an important role in regulating chlorophyll biosynthesis, but suppressed plant growth and yield in transgenic Arabidopsis.

scholarly journals The Streptomyces volatile 3-octanone alters auxin/cytokinin and growth in Arabidopsis thaliana via the gene family KISS ME DEADLY

2020 ◽  
Author(s):  
Bradley R. Dotson ◽  
Vasiliki Verschut ◽  
Klas Flärdh ◽  
Paul G. Becher ◽  
Allan G. Rasmusson
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Gene Family ◽  
Growth Promotion ◽  
Lateral Roots ◽  
Primary Root ◽  
Growth Hormones ◽  
Loss Of Function ◽  
Growth Responses ◽  
Cytokinin Signaling

AbstractPlants enhance their growth in the presence of particular soil bacteria due to volatile compounds affecting the homeostasis of plant growth hormones. However, the mechanisms of volatile compound signaling and plant perception has been unclear. This study identifies the bioactive volatile 3-octanone as a plant growth stimulating volatile, constitutively emitted by the soil bacterium Streptomyces coelicolor grown on a rich medium. When 3-octanone is applied to developing Arabidopsis thaliana seedlings, a family-wide induction of the Kelch-repeat F-box genes known as KISS ME DEADLY (KMD) subsequently alters auxin/cytokinin homeostasis to promote the growth of lateral roots and inhibit the primary root. Loss of function of the KMD family or other alterations of auxin/cytokinin homeostasis suppresses the volatile-induced growth response. This reveals a function of KMDs in the pathway of microbial volatile perception and plant growth responses.Significance StatementVolatiles from soil microbes are profound stimulators of plant growth. This work identifies for the first time a plant hormone signaling regulator, the gene family KISS ME DEADLY (KMD), to be an early essential step in plant growth promotion by a soil bacterial volatile, 3-octanone. The KMD-regulated gene network alters the tissue sensitivity balance for the growth hormones auxin and cytokinin, modifying root growth rate and architecture. Previously, the Kelch repeat F-box gene family of KMDs have been shown to be important down-regulators of both positive cytokinin signaling and phenylpropanoid biosynthesis, but upstream cues were unknown. This report places the KMD family regulation of plant growth and defense into its biotic context.

The short-period mutant, toc1-1, alters circadian clock regulation of multiple outputs throughout development in Arabidopsis thaliana

Development ◽  
1998 ◽  
Vol 125 (3) ◽  
pp. 485-494 ◽  
Author(s):  
D.E. Somers ◽  
A.A. Webb ◽  
M. Pearson ◽  
S.A. Kay
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Clock ◽  
Red Light ◽  
Luciferase Reporter ◽  
Wild Type ◽  
Luciferase Reporter Gene ◽  
Environmental Signals ◽  
Developmental States ◽  
Short Period ◽  
Log Linear

The coordination of developmental and physiological events with environmental signals is facilitated by the action of the circadian clock. Here we report a new set of circadian clock-controlled phenotypes for Arabidopsis thaliana. We use these markers together with the short-period mutant, toc1-1, and the clock-controlled cab2::luciferase reporter gene to assess the nature of the circadian clock throughout development and to suggest the position of TOC1 within the circadian clock system. In dark-grown seedlings, the toc1-1 lesion conferred a short period to the cycling of cab2::luciferase luminescence, as previously found in light-grown plants, indicating that the circadian clocks in these two divergent developmental states share at least one component. Stomatal conductance rhythms were similarly approximately 3 hours shorter than wild type in toc1-1, suggesting that a cell-autonomous clockwork may be active in guard cells in 5- to 6-week-old leaves. The effect of daylength on flowering time in the C24 ecotype was diminished by toc1-1, and was nearly eliminated in the Landsberg erecta background where the plants flowered equally early in both short and long days. Throughout a 500-fold range of red light intensities, both the wild type and the mutant showed an inverse log-linear relationship of fluence rate to period, with a 2–3 hour shorter period for the mutant at all intensities. These results indicate that TOC1 acts on or within the clock independently of light input. Temperature entrainment appears normal in toc1-1, and the period-shortening effects of the mutant remain unchanged over a 20 degrees C temperature range. Taken together our results are consistent with the likelihood that TOC1 codes for an oscillator component rather than for an element of an input signaling pathway. In addition, the pervasive effect of toc1-1 on a variety of clock-controlled processes throughout development suggests that a single circadian system is primarily responsible for controlling most, if not all, circadian rhythms in the plant.

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