Project description:Hydrogen peroxide (H2O2) can act as a signaling molecule that influences various aspects of plant growth and development, including stress signaling and cell death. Catalase deficient plants are pioneering systems which accumulate hydrogen peroxide (H2O2) from peroxisomal origin during photorespiratory challenges. Respiratory burst oxidase homologues D and F are known to participate in intracellular oxidative stress response launched in cat2 mutants (Chaouch et al., 2012). We studied the compared the transcriptional response of cat2 rbohD and cat2 rbohF double mutants versus the cat2 background to further adress their role during photorespiratory stress. After 3 weeks of growth, leaf tissue from the three different genotypes was harvested in triplicate.
Project description:Hydrogen peroxide (H2O2) can act as a signaling molecule that influences various aspects of plant growth and development, including stress signaling and cell death. Catalase deficient plants are pioneering systems which accumulate hydrogen peroxide (H2O2) from peroxisomal origin during photorespiratory challenges. Respiratory burst oxidase homologues D and F are known to participate in intracellular oxidative stress response launched in cat2 mutants (Chaouch et al., 2012). We studied the compared the transcriptional response of cat2 rbohD and cat2 rbohF double mutants versus the cat2 background to further adress their role during photorespiratory stress.
Project description:Studies have shown that Respiratory Burst Oxidase Homolog B (RBOHB) are involved in stress response in rice plants. Primers were developed for amplification via Polymerase Chain Reaction (PCR) of a region that contained a simple sequence repeat (SSR) in RBOHB. PCR was performed on 6 different varieties of Oryza sativa. PCR product was sequenced on an ABI 3730 capillary sequence machine. Sequence data was aligned to observe differences in SSR length between each rice variety.
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respiratory burst is necessary for tolerance to high temperatures in Arabidopsis (Larkindale, Torres, Jones and Knight, unpublished).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
Project description:Systemic acquired resistance (SAR) is a long-lasting broad-spectrum plant defense mechanism that is induced by mobile signals generated in the primarily infected leaves. Although multiple mobile SAR signals have been proposed, how these signals are perceived in the systemic leaves is unknown. Here, we show that extracellular nicotinamide adenine dinucleotide (phosphate) (eNAD(P)) accumulates in the systemic leaves and that both eNAD(P) and its receptor, the lectin receptor kinase (LecRK), LecRK-VI.2, are required in the systemic leaves for the establishment of SAR. Moreover, the mobile signal N-hydroxypipecolic acid (NHP) induces de novo NAD(P) leakage in the systemic leaves through the respiratory burst oxidase homolog RBOHF-produced reactive oxygen species (ROS). Importantly, NHP-induced systemic immunity depends on ROS, eNAD(P), and the eNAD(P) receptor complex LecRK-VI.2/ BAK1, indicating that NHP triggers SAR through the ROS-eNAD(P)-LecRK-VI.2/BAK1 signaling pathway. Our results uncovered a long-sought-after mechanism underlying the perception of mobile SAR signals in the systemic leaves
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.