Project description:Stomata regulate gas exchange between plants and the atmosphere by integrating opening and closing signals. Stomata open in response to low CO2 concentrations to maximize photosynthesis in the light; however, the mechanisms that coordinate photosynthesis and stomatal conductance have yet to be identified. Here, we characterize CBC1/2 [CONVERGENCE of BLUE LIGHT (BL) and CO2 1/2], two kinases that link BL, a major component of photosynthetically active radiation (PAR), and the signals from low concentrations of CO2 in guard cells. CBC1/CBC2 redundantly stimulate stomatal opening by negatively regulating S-type anion channels in response to both BL and low concentrations of CO2. CBC1/CBC2 function in the signaling pathways of phototropins and HT1 (HIGH LEAF TEMPERATURE 1). CBC1/CBC2 interacted with and were phosphorylated by HT1. We propose that CBCs regulate stomatal aperture by integrating signals from BL and CO2 and act as the convergence site for signals from PAR and low CO2.
Project description:Environmental stimuli, including elevated CO2, regulate stomatal development1-3 but the key mechanisms mediating the perception and relay of the CO2 signal to the stomatal development machinery remain elusive. To adapt CO2 intake to water loss, plants regulate the development of stomatal gas exchange pores in the aerial epidermis. Diverse plant species show a decrease in stomatal density in response to the continuing rise of atmospheric CO2 4. To date, one mutant, hic5, defective in cell wall wax biosynthesis, has been identified that exhibits a de-regulation of this CO2-controlled stomatal development response. Here we show that recently isolated Arabidopsis thaliana carbonic anhydrase double mutant plants6 exhibit an inversion in their response to elevated CO2, showing increased stomatal development at elevated CO2 levels. We have characterized the mechanisms mediating this response and demonstrate extracellular signaling in the regulation of CO2-controlled stomatal development by carbonic anhydrases. Transcriptomic RNA-Seq analyses show that the extracellular pro-peptide gene EPF2 7,8, but not EPF1 9, is induced at elevated CO2 in wild type, but not ca1ca4 mutant leaves. Moreover, EPF2 is essential for CO2 control of stomatal development. Using cell wall proteomic and CO2-dependent transcriptome analyses, we have identified a novel, CO2-induced extracellular protease, CRSP (CO2 Response Secreted Protease), as a mediator of CO2 controlled stomatal development. Our results identify mechanisms and genes that function in the repression of stomatal development in leaves during atmospheric CO2 elevation, including the CA1/CA4 carbonic anhydrases and the secreted protease CRSP that cleaves the pro-peptide EPF2, which in turn represses stomatal development.
2014-08-22 | PXD000956 | Pride
Project description:GABA does not regulate stomatal CO2 signalling in Arabidopsis
| PRJNA1087448 | ENA
Project description:GABA does not regulate stomatal CO2 signalling in Arabidopsis
Project description:Atmospheric CO2 concentrations can determine the number of stomata that form on plant leaves (Woodward & Kelly 1995 New Phyt 131: 311-327). The majority of species exhibit reduced stomatal densities at elevated CO2. However, not all plant species react in the same way to elevated CO2 levels and there is a spectrum of effects: Some species increase stomatal densities, some decrease stomatal densities, and some are unaffected. In addition to which, other environmental factors influence the number of stomata that a plant form. Light intensity has also been shown to affect stomatal numbers in various Arabidopsis ecotypes (Schluter et al. 2003 J Exp Bot 54 (383): 867-874; Lake et al. 2002 J Exp Bot 53 (367): 183-193), by increasing stomatal numbers with increasing light levels. There are many changes in gene expression under elevated CO2 conditions, so pinpointing specific genes involved in the stomatal response to CO2 is difficult. In addition, if there is crosstalk between the various signalling pathways affecting ultimate stomatal numbers this complicates further the task of finding genes specifically involved the stomatal response to CO2. Therefore we propose to look at the interaction of two known influences on stomatal numbers, light and CO2, on one specific ecotype, Col-0. We aim to test the hypothesis that light signals interact the CO2 signals that affect stomatal development. Arabidopsis thaliana Columbia-0 ecotype has previously been shown to decrease stomatal numbers in response to a doubling of ambient CO2 concentrations. Col-0 has also been shown to increase stomatal numbers in response to high light intensities. Therefore we propose to grow A. thaliana Col-0 at three light intensities (50 mmol m-2 s-1, 150 mmol m-2 s-1 and 250 mmol m-2 s-1), in both ambient and elevated (double ambient) atmospheric CO2 concentrations. By looking in more detail at how gene expression differs between plants grown at ambient and elevated CO2 at the same light intensities, and also how gene expression differs between plants grown at the same CO2 concentration but different light intensities, we aim to identify those genes involved in the stomatal developmental response to CO2 and whether genes involved in the light response can also be isolated.
Project description:Atmospheric CO2 concentrations can determine the number of stomata that form on plant leaves (Woodward & Kelly 1995 New Phyt 131: 311-327). The majority of species exhibit reduced stomatal densities at elevated CO2. However, not all plant species react in the same way to elevated CO2 levels and there is a spectrum of effects: Some species increase stomatal densities, some decrease stomatal densities, and some are unaffected. In addition to which, other environmental factors influence the number of stomata that a plant form. Light intensity has also been shown to affect stomatal numbers in various Arabidopsis ecotypes (Schluter et al. 2003 J Exp Bot 54 (383): 867-874; Lake et al. 2002 J Exp Bot 53 (367): 183-193), by increasing stomatal numbers with increasing light levels. There are many changes in gene expression under elevated CO2 conditions, so pinpointing specific genes involved in the stomatal response to CO2 is difficult. In addition, if there is crosstalk between the various signalling pathways affecting ultimate stomatal numbers this complicates further the task of finding genes specifically involved the stomatal response to CO2. Therefore we propose to look at the interaction of two known influences on stomatal numbers, light and CO2, on one specific ecotype, Col-0. We aim to test the hypothesis that light signals interact the CO2 signals that affect stomatal development. Arabidopsis thaliana Columbia-0 ecotype has previously been shown to decrease stomatal numbers in response to a doubling of ambient CO2 concentrations. Col-0 has also been shown to increase stomatal numbers in response to high light intensities. Therefore we propose to grow A. thaliana Col-0 at three light intensities (50 mmol m-2 s-1, 150 mmol m-2 s-1 and 250 mmol m-2 s-1), in both ambient and elevated (double ambient) atmospheric CO2 concentrations. By looking in more detail at how gene expression differs between plants grown at ambient and elevated CO2 at the same light intensities, and also how gene expression differs between plants grown at the same CO2 concentration but different light intensities, we aim to identify those genes involved in the stomatal developmental response to CO2 and whether genes involved in the light response can also be isolated. Experimenter name = Susannah Bird Experimenter phone = (0114) 222 4649 Experimenter address = Animal and Plant Science Department Experimenter address = Alfred Denny Building Experimenter address = Western Bank Experimenter address = Sheffield Experimenter zip/postal_code = S10 2TN Experimenter country = UK Keywords: growth_condition_design
Project description:In plants, epidermal guard cells integrate and respond to numerous environmental signals to control stomatal pore apertures thereby regulating gas exchange. Chromatin structure controls transcription factor access to the genome, but whether large-scale chromatin remodeling occurs in guard cells during stomatal movements, and in response to the hormone abscisic acid (ABA) in general, remain unknown. Here we isolate guard cell nuclei from Arabidopsis thaliana plants to examine whether the physiological signals, ABA and CO2, regulate guard cell chromatin during stomatal movements. Our cell type specific analyses uncover patterns of chromatin accessibility specific to guard cells and define novel cis-regulatory sequences supporting guard cell specific gene expression. We find that ABA triggers extensive and dynamic chromatin remodeling in guard cells, roots, and mesophyll cells with clear patterns of cell-type specificity. DNA motif analyses uncover binding sites for distinct transcription factors enriched in ABA-induced and ABA-repressed chromatin. We identify the ABF/AREB bZIP-type transcription factors that are required for ABA-triggered chromatin opening in guard cells and implicate the inhibition of a set of bHLH-type transcription factors in controlling ABA-repressed chromatin. Moreover, we demonstrate that ABA and CO2 induce distinct programs of chromatin remodeling. We provide insight into the control of guard cell chromatin dynamics and propose that ABA-induced chromatin remodeling primes the genome for abiotic stress resistance.
Project description:In plants, epidermal guard cells integrate and respond to numerous environmental signals to control stomatal pore apertures thereby regulating gas exchange. Chromatin structure controls transcription factor access to the genome, but whether large-scale chromatin remodeling occurs in guard cells during stomatal movements, and in response to the hormone abscisic acid (ABA) in general, remain unknown. Here we isolate guard cell nuclei from Arabidopsis thaliana plants to examine whether the physiological signals, ABA and CO2, regulate guard cell chromatin during stomatal movements. Our cell type specific analyses uncover patterns of chromatin accessibility specific to guard cells and define novel cis-regulatory sequences supporting guard cell specific gene expression. We find that ABA triggers extensive and dynamic chromatin remodeling in guard cells, roots, and mesophyll cells with clear patterns of cell-type specificity. DNA motif analyses uncover binding sites for distinct transcription factors enriched in ABA-induced and ABA-repressed chromatin. We identify the ABF/AREB bZIP-type transcription factors that are required for ABA-triggered chromatin opening in guard cells and implicate the inhibition of a set of bHLH-type transcription factors in controlling ABA-repressed chromatin. Moreover, we demonstrate that ABA and CO2 induce distinct programs of chromatin remodeling. We provide insight into the control of guard cell chromatin dynamics and propose that ABA-induced chromatin remodeling primes the genome for abiotic stress resistance.
Project description:Atmospheric CO2 concentrations can determine the number of stomata that form on plant leaves (Woodward & Kelly 1995 New Phyt 131: 311-327). The majority of species exhibit reduced stomatal densities at elevated CO2. However, not all plant species react in the same way to elevated CO2 levels and there is a spectrum of effects: Some species increase stomatal densities, some decrease stomatal densities, and some are unaffected. In addition to which, other environmental factors influence the number of stomata that a plant form. Light intensity has also been shown to affect stomatal numbers in various Arabidopsis ecotypes (Schluter et al. 2003 J Exp Bot 54 (383): 867-874; Lake et al. 2002 J Exp Bot 53 (367): 183-193), by increasing stomatal numbers with increasing light levels. There are many changes in gene expression under elevated CO2 conditions, so pinpointing specific genes involved in the stomatal response to CO2 is difficult. In addition, if there is crosstalk between the various signalling pathways affecting ultimate stomatal numbers this complicates further the task of finding genes specifically involved the stomatal response to CO2. Therefore we propose to look at the interaction of two known influences on stomatal numbers, light and CO2, on one specific ecotype, Col-0. We aim to test the hypothesis that light signals interact the CO2 signals that affect stomatal development. Arabidopsis thaliana Columbia-0 ecotype has previously been shown to decrease stomatal numbers in response to a doubling of ambient CO2 concentrations. Col-0 has also been shown to increase stomatal numbers in response to high light intensities. Therefore we propose to grow A. thaliana Col-0 at three light intensities (50 mmol m-2 s-1, 150 mmol m-2 s-1 and 250 mmol m-2 s-1), in both ambient and elevated (double ambient) atmospheric CO2 concentrations. By looking in more detail at how gene expression differs between plants grown at ambient and elevated CO2 at the same light intensities, and also how gene expression differs between plants grown at the same CO2 concentration but different light intensities, we aim to identify those genes involved in the stomatal developmental response to CO2 and whether genes involved in the light response can also be isolated. Experimenter name = Susannah Bird; Experimenter phone = (0114) 222 4649; Experimenter address = Animal and Plant Science Department; Experimenter address = Alfred Denny Building; Experimenter address = Western Bank; Experimenter address = Sheffield; Experimenter zip/postal_code = S10 2TN; Experimenter country = UK Experiment Overall Design: 6 samples were used in this experiment