The role of the OX1 protein kinase in H2O2 signal transduction
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
SUBMITTER: David Craigon
PROVIDER: E-NASC-5 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Aim: To determine the effect of an AtrbohC mutation on the gene expression pattern in primary root tissue, to identify candidate genes acting downstream of AtrbohC, particularly any encoding antioxidant-related proteins, signal transduction components or proteins known to be required for normal root-hair development. Background: Root-hairs are a model system for investigating plant cell polarity. The root-hair mutant rhd2 (Schiefelbein and Somerville, 1990. Plant Cell, 2:235) has short hairs that burst at their tips, (Jones and Smirnoff, unpublished). RHD2 has been cloned and is identical to AtrbohC (L. Dolan, pers. comm.), which encodes a homologue of the superoxide-generating neutrophil respiratory burst oxidase catalytic subunit gp91phox (Torres et al., 1998. Plant J., 14:365). Superoxide rapidly dismutates to hydrogen peroxide (H2O2), suggesting that the rhd2 phenotype may result from reduced H2O2 levels in root-hair cells. Low doses of exogenous antioxidants phenocopy the rhd2 root-hair phenotype in wild-type plants (Jones and Smirnoff, unpublished) further supporting a role for H2O2 in root-hair growth. Fluorescent dyes that detect H2O2 show distinct localisation patterns in growing root-hair cells, (Jones and Smirnoff, unpublished). H2O2 may be an important second messenger in plant cell signalling with proposed roles in the development of cotton fibres (Potikha et al., 1999. Plant Physiol., 119: 849) and in ABA-induced stomatal closure (Zhang et al., 2001. Plant Physiol., 126: 1438). In cultured Arabidopsis cells H2O2 induces gene expression, including that of a gp91phox homologue, (Desikan et al., 1998. J. Exp. Bot., 49: 1767; Desikan, et al., 2000. Free Rad. Biol. Med., 28: 773; Baxter-Burrell et al., 2002. Science, 296: 2026) and activates a MAP kinase cascade (Desikan et al., 1999. J. Exp Bot., 50: 1863). cDNA microarray technology has been used previously to examine the effects of H2O2 on gene expression during oxidative stress (Desikan et al., 2001. Plant Physiol., 127: 159). We wish to investigate the effects of H2O2 on gene expression during root development using the rhd2 mutant. We are currently determining the expression pattern of RHD2. By extracting RNA from the small region of the primary root (for wild-type and rhd2 plants grown in sterile conditions) where root hairs are growing we hope to enrich for root-hair RNAs. This may reveal candidate genes that could be examined more closely at the single-cell level. This approach will provide new insights into the role of H2O2 in root-hair development.
2022-11-21 | E-NASC-54 | biostudies-arrayexpress
Project description:Aim: To determine the effect of an AtrbohC mutation on the gene expression pattern in primary root tissue, to identify candidate genes acting downstream of AtrbohC, particularly any encoding antioxidant-related proteins, signal transduction components or proteins known to be required for normal root-hair development. Background: Root-hairs are a model system for investigating plant cell polarity. The root-hair mutant rhd2 (Schiefelbein and Somerville, 1990. Plant Cell, 2:235) has short hairs that burst at their tips, (Jones and Smirnoff, unpublished). RHD2 has been cloned and is identical to AtrbohC (L. Dolan, pers. comm.), which encodes a homologue of the superoxide-generating neutrophil respiratory burst oxidase catalytic subunit gp91phox (Torres et al., 1998. Plant J., 14:365). Superoxide rapidly dismutates to hydrogen peroxide (H2O2), suggesting that the rhd2 phenotype may result from reduced H2O2 levels in root-hair cells. Low doses of exogenous antioxidants phenocopy the rhd2 root-hair phenotype in wild-type plants (Jones and Smirnoff, unpublished) further supporting a role for H2O2 in root-hair growth. Fluorescent dyes that detect H2O2 show distinct localisation patterns in growing root-hair cells, (Jones and Smirnoff, unpublished). H2O2 may be an important second messenger in plant cell signalling with proposed roles in the development of cotton fibres (Potikha et al., 1999. Plant Physiol., 119: 849) and in ABA-induced stomatal closure (Zhang et al., 2001. Plant Physiol., 126: 1438). In cultured Arabidopsis cells H2O2 induces gene expression, including that of a gp91phox homologue, (Desikan et al., 1998. J. Exp. Bot., 49: 1767; Desikan, et al., 2000. Free Rad. Biol. Med., 28: 773; Baxter-Burrell et al., 2002. Science, 296: 2026) and activates a MAP kinase cascade (Desikan et al., 1999. J. Exp Bot., 50: 1863). cDNA microarray technology has been used previously to examine the effects of H2O2 on gene expression during oxidative stress (Desikan et al., 2001. Plant Physiol., 127: 159). We wish to investigate the effects of H2O2 on gene expression during root development using the rhd2 mutant. We are currently determining the expression pattern of RHD2. By extracting RNA from the small region of the primary root (for wild-type and rhd2 plants grown in sterile conditions) where root hairs are growing we hope to enrich for root-hair RNAs. This may reveal candidate genes that could be examined more closely at the single-cell level. This approach will provide new insights into the role of H2O2 in root-hair development. Experiment Overall Design: Number of plants pooled:100
2008-06-14 | E-GEOD-6165 | biostudies-arrayexpress
Project description:We have been determining signalling components essential for heat tolerance in Arabidopsis thaliana (Larkindale, J., and Knight, M.R. (2002). Protection against heat stress-induced oxidative damage in Arabidopsis involves calcium, abscisic acid, ethylene, and salicylic acid. Plant Physiol 128, 682-695). We have most recently found that a heat-induced respiratory burst is necessary for tolerance to high temperatures in Arabidopsis (Larkindale, Torres, Jones and Knight, unpublished). We have observed that one of the Arabidopsis respiratory burst homologues, AtrbohB, is necessary for the generation of this AOS burst in response to heat, and consequently we have also found that an AtrbohB null mutant shows reduced tolerance to heating (Larkindale, Torres, Jones and Knight, unpublished). This mutant also shows reduced expression of genes from the HSP90 family (Evans, Larkindale and Knight, unpublished).This application is for transcriptomic analysis of the AtrbohB null mutant in response to heat, in order to understand which genes are activated as a result of heat-induced respiratory bursts in Arabidopsis and also which genes are necessary for physiological thermotolerance in Arabidopsis. The experiment will involve 6 samples (chips), 3 from wild type Columbia and 3 from the AtrbohB null mutant. Seedlings will be treated at 20, 30 and 40 degrees centigrade for 1 hour, RNA extracted and submitted to microarray analysis. One hour treatment has been shown to display clear differences in HSP90 expression and physiological damage, and the temperatures chosen because 30 degrees is a temperature at which acquired thermotolerance can be initiated (thus genes involved in this process can be monitored) and 40 degrees is a temperature at which we observe physiological damage, and gives good discrimination between mutant and wild type.
2022-11-21 | E-NASC-24 | biostudies-arrayexpress
Project description:We have been determining signalling components essential for heat tolerance in Arabidopsis thaliana (Larkindale, J., and Knight, M.R. (2002). Protection against heat stress-induced oxidative damage in Arabidopsis involves calcium, abscisic acid, ethylene, and salicylic acid. Plant Physiol 128, 682-695). We have most recently found that a heat-induced respiratory burst is necessary for tolerance to high temperatures in Arabidopsis (Larkindale, Torres, Jones and Knight, unpublished). We have observed that one of the Arabidopsis respiratory burst homologues, AtrbohB, is necessary for the generation of this AOS burst in response to heat, and consequently we have also found that an AtrbohB null mutant shows reduced tolerance to heating (Larkindale, Torres, Jones and Knight, unpublished). This mutant also shows reduced expression of genes from the HSP90 family (Evans, Larkindale and Knight, unpublished).This application is for transcriptomic analysis of the AtrbohB null mutant in response to heat, in order to understand which genes are activated as a result of heat-induced respiratory bursts in Arabidopsis and also which genes are necessary for physiological thermotolerance in Arabidopsis. The experiment will involve 6 samples (chips), 3 from wild type Columbia and 3 from the AtrbohB null mutant. Seedlings will be treated at 20, 30 and 40 degrees centigrade for 1 hour, RNA extracted and submitted to microarray analysis. One hour treatment has been shown to display clear differences in HSP90 expression and physiological damage, and the temperatures chosen because 30 degrees is a temperature at which acquired thermotolerance can be initiated (thus genes involved in this process can be monitored) and 40 degrees is a temperature at which we observe physiological damage, and gives good discrimination between mutant and wild type. Experiment Overall Design: Number of plants pooled:90 per sample
2008-06-14 | E-GEOD-6154 | biostudies-arrayexpress
Project description:Plant growth and development are strongly affected by light signals perceived by phytochromes (phy) and cryptochromes (cry). The physical interaction between photoreceptors and the cross-talk among downstream signalling steps creates a network of interactions in which the action of one photoreceptor depends on the status of the others. The processes modulated by phy and or cry include seed germination, seedling de-etiolation, plant body formation and flowering. Compared to the wild type the leaves of the phyB mutant are characterised by their extended petioles and pale colour. These features resemble the phenotype of normal plants grown under the low red to far-red ratios typical of dense plant canopies thus providing support to the idea that phyB plays a key role in the perception of high red to far-red ratios. The triple mutant lacking phyA cry1 and cry2 shows little differences in leaf size and shape with the wild typebut the quadruple phyA phyB cry1 cry2 mutant shows severely impaired leaf expansion. In addition to the specific effects on leaf sizeshape and pigmentation the phyB mutation accelerates flowering in the wild type background. This effect can be observed as a reduced number of days between sowing and visible flower buds (time scale) and as a reduced final number of leaves (developmental scale). However in the phyA cry1 cry2 triple mutant background the phyB mutation accelerates flowering on a developmental scale but severely delays flowering on a time scale. The long photoperiods inducing flowering are perceived by the leaves. Flowering signals that could include hormones and sugars migrate from the leaves to the apex in response to the light stimulus. We propose to compare the following mRNA samples of expanding leaves: 1) wild type 2) phyB mutant 3) phyA cry1 cry2 triple mutant 4) phyA phyB cry1 cry2 quadruple mutant. The comparison between the wild type and the phyB mutant will help to uncover the changes in leaf mRNA patterns underlying enhanced petiole growthreduced pigmentation and early flowering in response to the absence of phyB activity. The comparison between the phyA cry1 cry2 triple mutant and the phyA phyB cry1 cry2 quadruple mutant should reveal the mRNA differences between photosynthetic leaves with dramatically different abilities to expand. The added value of the simultaneous analysis of the two comparisons is that effect of phyB is different in both genetic backgrounds and this should provide information on the mechanisms and significance of photoreceptor interactions.
2003-10-29 | E-NASC-6 | biostudies-arrayexpress
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2003-10-20 | E-NASC-10 | biostudies-arrayexpress
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2022-11-21 | E-NASC-42 | biostudies-arrayexpress
Project description:Many signalling pathways are involved in controlling gene expression during plant senescence. Pathways involving SA, JA and ethylene have a role in senescence but none are essential for the senescence process to occur. The aim of this experiment is to classify senescence-enhanced genes into groups depending on the signalling pathways that regulate them. This will provide useful information on the relative importance of each signalling pathway during senescence and allow us to separate potential senescence-specific genes and pathways from the stress response pathways.Mutants in genes in the ethylene pathway (ein2) and the jasmonate pathway (coi1) and the NahG transgenic plant which is defective in the salicylic acid pathway will be grown until the mid flowering stage. Fully developed green and partially senescent leaves will be harvested from the plants at this stage. In addition, two different lines of Arabidopsis (Col-5 glabrous and Col-0) will be grown as controls. Leaves will be harvested from the two control plants before flowering (green) and at mid flowering as above. The control plants will be harvested at two stages to identify the senescence- enhanced genes. The effects of each mutation on the senescence related expression of these genes will then be studied.Mutant RNAs will be isolated in duplicate. The two control accessions will act as replicates for the wild type. Two wild type accessions will be used to reduce possible differences that could be observed the mutants due to slight differences in background.
2022-11-21 | E-NASC-17 | biostudies-arrayexpress
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2022-11-21 | E-NASC-57 | biostudies-arrayexpress
Project description:Aim: To identify regulatory factors that control: (1) chloroplast protein importand (2) chloroplast-to-nucleus signalling. This project is a joint proposal from the Jarvis lab which is interested in chloroplast protein import [1] and the Moller lab which is interested in plastid-to-nucleus signalling [2]. Background: The majority of chloroplast proteins are encoded in the nucleus and imported post-translationally into chloroplasts. The abundance of chloroplast proteins may therefore be regulated at multiple levels. It is well documented that the nuclear gene expression is responsive to (largely unknown) signals from the chloroplast [23] and evidence is now emerging that protein import is also a regulated process [1]. Protein import into chloroplasts is mediated by protein complexes in the outer and inner envelope membranes called Toc and Tic respectively. Biochemical studies of pea chloroplasts identified several Toc/Tic components. These proteins are mechanistic or structural components of the import apparatus. Arabidopsis homologues of the pea Toc/Tic proteins were identified by the AGI. Pea Toc34 is represented in Arabidopsis by two genes "Toc33 and Toc34" and pea Toc75 is represented by three genes. These different Tocs have different expression patterns and are proposed to have different precursor protein recognition specificities. The factors that regulate Toc expression in concert with the needs of plastids in developmentally different cells are unknown. Proposal: Two Arabidopsis mutants will be analysed. The ppi1 mutant is null for the putative precursor protein receptor Toc33 [1]and the ppi3 mutant is null for a putative component of the protein import channel Toc75-IV (on chromosome IV). ppi1 plants are yellow-green in appearance but remarkably healthy and grow only slightly more slowly than wild type. By contrast ppi3 plants are indistinguishable from wild type by eye although analysis of the mutant's chloroplast proteome is beginning to reveal some differences (K. Lilley personal communication). Gene expression changes in ppi1 are likely to be quite extensive. Retardation of chloroplast development in ppi1 will activate retrograde signalling pathways so that many nuclear photosynthetic genes are down-regulated. Changes in the expression of photosynthetic genes and of the genes responsible for mediating these responses may therefore be observed. Any regulatory and signalling genes identified will be of interest to the Moller lab. The expression of factors that regulate Toc/Tic gene expression may also be altered in ppi1. It should be possible to distinguish these factors from those involved in the general control of chloroplast gene expression by comparing the results from the two mutants. Genes affected in both mutants are more likely to be involved in regulating chloroplast import since it is unlikely that widespread changes in gene expression will be observed in ppi3. Changes in the expression of factors that regulate import post-translationallyand of the Toc/Tic genes themselves (many are on the RNA) may also be observed. References: 1. Jarvis P. et al. (1998) Science 282: 100-103. 2. Moller S.G. et al. (2001) Genes Dev. 15:90-103. 3. Jarvis P. (2001) Curr. Biol. 11: R307-R310.
2022-11-21 | E-NASC-35 | biostudies-arrayexpress