CYP707As are effectors of karrikin and strigolactone signalling pathways in Arabidopsis thaliana and parasitic plants

2019 ◽  
Vol 42 (9) ◽  
pp. 2612-2626 ◽  
Author(s):  
Guillaume Brun ◽  
Séverine Thoiron ◽  
Lukas Braem ◽  
Jean‐Bernard Pouvreau ◽  
Grégory Montiel ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Parasitic Plants ◽  
Signalling Pathways ◽  
Strigolactone Signalling

scholarly journals Kinetics of retrograde signalling initiation in the high light response of Arabidopsis thaliana

2014 ◽  
Vol 369 (1640) ◽  
pp. 20130424 ◽  
Author(s):  
Khalid Alsharafa ◽  
Marc Oliver Vogel ◽  
Marie-Luise Oelze ◽  
Marten Moore ◽  
Nadja Stingl ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Nuclear Gene ◽  
Light Response ◽  
High Light ◽  
Time Dependent ◽  
Signalling Pathways ◽  
Minor Role ◽  
Intensity Increase ◽  
Normal Light ◽  
Set Up

High light acclimation depends on retrograde control of nuclear gene expression. Retrograde regulation uses multiple signalling pathways and thus exploits signal patterns. To maximally challenge the acclimation system, Arabidopsis thaliana plants were either adapted to 8 (low light (L-light)) or 80 µmol quanta m −2 s −1 (normal light (N-light)) and subsequently exposed to a 100- and 10-fold light intensity increase, respectively, to high light (H-light, 800 µmol quanta m −2 s −1 ), for up to 6 h. Both L → H- and N → H-light plants efficiently regulated CO 2 assimilation to a constant level without apparent damage and inhibition. This experimental set-up was scrutinized for time-dependent regulation and efficiency of adjustment. Transcriptome profiles revealed that N-light and L-light plants differentially accumulated 2119 transcripts. After 6 h in H-light, only 205 remained differently regulated between the L → H- and N → H-light plants, indicating efficient regulation allowing the plants to reach a similar transcriptome state. Time-dependent analysis of transcripts as markers for signalling pathways, and of metabolites and hormones as possibly involved transmitters, suggests that oxylipins such as oxophytodienoic acid and jasmonic acid, metabolites and redox cues predominantly control the acclimation response, whereas abscisic acid, salicylic acid and auxins play an insignificant or minor role.

scholarly journals AtRsgA from Arabidopsis thaliana controls maturation of the small subunit of the chloroplast ribosome

2017 ◽  
Author(s):  
Marcin Janowski ◽  
Reimo Zoschke ◽  
Lars Scharff ◽  
Silvia Martinez Jaime ◽  
Camilla Ferrari ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Proteomic Analysis ◽  
Ribosome Biogenesis ◽  
Functional Characterization ◽  
Small Subunit ◽  
Signalling Pathways ◽  
Compensatory Mechanism ◽  
Transcriptional Responses ◽  
Retrograde Signalling ◽  
Assembly Factor

SummaryPlastid ribosomes are very similar in structure and function to ribosomes of their bacterial ancestors. Since ribosome biogenesis is not thermodynamically favourable at biological conditions, it requires activity of many assembly factors. Here, we have characterized a homolog of bacterial rsgA in Arabidopsis thaliana and show that it can complement the bacterial homolog. Functional characterization of a strong mutant in Arabidopsis revealed that the protein is essential for plant viability, while a weak mutant produced dwarf, chlorotic plants that incorporated immature pre-16S ribosomal RNA into translating ribosomes. Physiological analysis of the mutant plants revealed smaller, but more numerous chloroplasts in the mesophyll cells, reduction of chlorophyll a and b, depletion of proplastids from the rib meristem and decreased photosynthetic electron transport rate and efficiency. Comparative RNA-sequencing and proteomic analysis of the weak mutant and wild-type plants revealed that various biotic stress-related, transcriptional regulation and post-transcriptional modification pathways were repressed in the mutant. Intriguingly, while nuclear- and chloroplast-encoded photosynthesis-related proteins were less abundant in the mutant, the corresponding transcripts were upregulated, suggesting an elaborate compensatory mechanism, potentially via differentially active retrograde signalling pathways. To conclude, this study reveals a new chloroplast ribosome assembly factor and outlines the transcriptomic and proteomic responses of the compensatory mechanism activated during decreased chloroplast function.Significance statementAtRsgA is an assembly factor necessary for maturation of the small subunit of the chloroplast ribosome. Depletion of AtRsgA leads to dwarfed, chlorotic plants and smaller, but more numerous chloroplasts. Large-scale transcriptomic and proteomic analysis revealed that chloroplast-encoded and - targeted proteins were less abundant, while the corresponding transcripts were upregulated in the mutant. We analyse the transcriptional responses of several retrograde signalling pathways to suggest a mechanism underlying this compensatory response.

Interaction of stomatal responses to ABA and CO2 in Arabidopsis thaliana

1998 ◽  
Vol 25 (7) ◽  
pp. 785 ◽  
Author(s):  
Juliette Leymarie ◽  
Gérard Lascève ◽  
Alain Vavasseur
Keyword(s):  
Arabidopsis Thaliana ◽  
Leaf Conductance ◽  
Signalling Pathways ◽  
Co2 Removal ◽  
Wild Type ◽  
Stomatal Responses ◽  
Whole Plant ◽  
Aba Insensitive ◽  
Rapid Drop

Stomatal responses to ABA and CO2 were investigated in Arabidopsis thaliana (L.) Heynh. wild-type and ABA insensitive mutants (abi1-1, abi2-1, abi1-1abi2-1) at the whole plant and at the isolated epidermis levels. In wild-type plants, feeding roots with ABA (1–50 µM) triggered a rapid drop in leaf conductance which levelled off during the following photoperiods, and strongly inhibited the increase in conductance induced by light. The rapid response was strongly inhibited in abi1-1, abi2-1 and abi1-1abi2-1 double mutants, but a residual long-term decrease in leaf conductance was still observed. In wild-type plants, exogenous ABA strongly enhanced the response to CO2 removal. Conversely, in the absence of CO2 the effect of ABA was drastically reduced in epidermal strip experiments. These results reveal a strong interaction between sensing of ABA and CO2 in stomata of A. thaliana. Despite an initially wide stomatal aperture in abi-1, abi-2 and double mutant plants, their stomatal responses to light and CO2 removal were half those of wild-type plants. Moreover these responses were totally independent of the presence of ABA, suggesting that ABI1 and ABI2 are either directly involved in the interaction between the two signalling pathways or, alternatively located upstream of this point of interaction.

scholarly journals Plasma-Activated Water Triggers Rapid and Sustained Cytosolic Ca2+ Elevations in Arabidopsis thaliana

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2516
Author(s):  
Enrico Cortese ◽  
Alessio G. Settimi ◽  
Silvia Pettenuzzo ◽  
Luca Cappellin ◽  
Alessandro Galenda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Defence ◽  
Chemical Species ◽  
Plasma Discharge ◽  
Signalling Pathways ◽  
Operational Conditions ◽  
Defence Responses ◽  
Promote Plant Growth ◽  
Plant Defence Responses ◽  
Plasma Activated Water

Increasing evidence indicates that water activated by plasma discharge, termed as plasma-activated water (PAW), can promote plant growth and enhance plant defence responses. Nevertheless, the signalling pathways activated in plants in response to PAW are still largely unknown. In this work, we analysed the potential involvement of calcium as an intracellular messenger in the transduction of PAW by plants. To this aim, Arabidopsis thaliana (Arabidopsis) seedlings stably expressing the bioluminescent Ca2+ reporter aequorin in the cytosol were challenged with PAW generated by a plasma torch. Ca2+ measurement assays demonstrated the induction by PAW of rapid and sustained cytosolic Ca2+ elevations in Arabidopsis seedlings. The dynamics of the recorded Ca2+ signals were found to depend upon different parameters, such as the operational conditions of the torch, PAW storage, and dilution. The separate administration of nitrate, nitrite, and hydrogen peroxide at the same doses as those measured in the PAW did not trigger any detectable Ca2+ changes, suggesting that the unique mixture of different reactive chemical species contained in the PAW is responsible for the specific Ca2+ signatures. Unveiling the signalling mechanisms underlying plant perception of PAW may allow to finely tune its generation for applications in agriculture, with potential advantages in the perspective of a more sustainable agriculture.

A methodology for carbamate post-translational modification discovery and its application in Escherichia coli

2021 ◽  
Vol 11 (2) ◽  
pp. 20200028
Author(s):  
Victoria L. Linthwaite ◽  
Martin J. Cann
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
Arabidopsis Thaliana ◽  
Protein Interactions ◽  
Signalling Pathways ◽  
Post Translational Modification ◽  
Cellular Targets ◽  
Biologically Relevant ◽  
Cellular Processes ◽  
Cell Phenotypes

Carbon dioxide can influence cell phenotypes through the modulation of signalling pathways. CO 2 regulates cellular processes as diverse as metabolism, cellular homeostasis, chemosensing and pathogenesis. This diversity of regulated processes suggests a broadly conserved mechanism for CO 2 interactions with diverse cellular targets. CO 2 is generally unreactive but can interact with neutral amines on protein under normal intracellular conditions to form a carbamate post-translational modification (PTM). We have previously demonstrated the presence of this PTM in a subset of protein produced by the model plant species Arabidopsis thaliana . Here, we describe a detailed methodology for identifying new carbamate PTMs in an extracted soluble proteome under biologically relevant conditions. We apply this methodology to the soluble proteome of the model prokaryote Escherichia coli and identify new carbamate PTMs . The application of this methodology, therefore, supports the hypothesis that the carbamate PTM is both more widespread in biology than previously suspected and may represent a broadly relevant mechanism for CO 2 –protein interactions.

scholarly journals Inhibitor-induced oxidation of the nucleus and cytosol in Arabidopsis thaliana: implications for organelle to nucleus retrograde signalling

2017 ◽  
Vol 372 (1730) ◽  
pp. 20160392 ◽  
Author(s):  
Barbara Karpinska ◽  
Sarah Owdah Alomrani ◽  
Christine H. Foyer
Keyword(s):  
Arabidopsis Thaliana ◽  
Redox State ◽  
Guard Cells ◽  
Signalling Pathways ◽  
Mrna Levels ◽  
Cellular Redox ◽  
Mitochondrial Inhibitors ◽  
Retrograde Signalling ◽  
Stomatal Guard Cells ◽  
Cellular Redox State

Concepts of organelle-to-nucleus signalling pathways are largely based on genetic screens involving inhibitors of chloroplast and mitochondrial functions such as norflurazon, lincomycin (LINC), antimycin A (ANT) and salicylhydroxamic acid. These inhibitors favour enhanced cellular oxidation, but their precise effects on the cellular redox state are unknown. Using the in vivo reduction–oxidation (redox) reporter, roGFP2, inhibitor-induced changes in the glutathione redox potentials of the nuclei and cytosol were measured in Arabidopsis thaliana root, epidermal and stomatal guard cells, together with the expression of nuclear-encoded chloroplast and mitochondrial marker genes. All the chloroplast and mitochondrial inhibitors increased the degree of oxidation in the nuclei and cytosol. However, inhibitor-induced oxidation was less marked in stomatal guard cells than in epidermal or root cells. Moreover, LINC and ANT caused a greater oxidation of guard cell nuclei than the cytosol. Chloroplast and mitochondrial inhibitors significantly decreased the abundance of LHCA1 and LHCB1 transcripts. The levels of WHY1 , WHY3 and LEA5 transcripts were increased in the presence of inhibitors. Chloroplast inhibitors decreased AOXA1 mRNA levels, while mitochondrial inhibitors had the opposite effect. Inhibitors that are used to characterize retrograde signalling pathways therefore have similar general effects on cellular redox state and gene expression. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

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