Project description:To identify chloroplastic H2O2-responseive genes, an estrogen-inducible RNAi method was used for silencing of tAPX, a H2O2-scavenging enzyme in chloroplasts. At 48 h after treatment with estrogen, the expression of tAPX was silenced in the IS-tAPX-19-23 plants, but not in the IS-GUS-2-17 plants (negative control), resulting a large change in gene expression. These genes are candidates for chloroplastic H2O2-responseive genes. IS-GUS-2-17 vs. IS-tAPX-19-23 leaves. Biological replicates 2.
Project description:To identify chloroplastic H2O2-responseive genes, an estrogen-inducible RNAi method was used for silencing of tAPX, a H2O2-scavenging enzyme in chloroplasts. At 48 h after treatment with estrogen, the expression of tAPX was silenced in the IS-tAPX-19-23 plants, but not in the IS-GUS-2-17 plants (negative control), resulting a large change in gene expression. These genes are candidates for chloroplastic H2O2-responseive genes.
Project description:The Oscillation Zone (OZ) of unsynchronized roots was dissected and divided into an upper (OZ2) and lower (OZ1) half . Samples were ordered according to DR5:GUS expression as analyzed by real time PCR to find periodic expression patterns Seedlings were grown for 5 days. 39 individual roots were dissected for RNA extraction. These microarray samples profile a specific region of the root tip designated as the Oscillation zone. Arrangement of the samples in the following order: OZ1-1, OZ1-4, OZ1-23, OZ1-14, OZ1-17, OZ1-2, OZ1-6, OZ1-13, OZ1-15, OZ1-16, OZ1-10, OZ1-32, OZ1-3, OZ1-31, OZ1-22, OZ1-35, OZ1-19, OZ1-9, OZ1-33, OZ1-20, OZ2-4, OZ2-23, OZ2-14, OZ2-6, OZ2-13, OZ2-15, OZ2-10, OZ2-32, OZ2-22, OZ2-35, OZ2-19, OZ2-9, OZ2-20, OZ2-36, OZ2-39, OZ2-21, OZ2-40, OZ2-38, OZ2-1, was used to identify periodic expression patterns.
Project description:OsPAO5 mainly functions to oxidize spermine and produce H2O2,which finally affects mesocotyl elongation in rice. Meanwhile ethylene and polyamines synthesis crosstalk has been reported in competing the common substrate. To further confirm the relationship between H2O2 and ethylene in contributing to the mesocotyl length, we conducted a transcriptome comparison between pao5-1 vs NIP, ACC-treatment vs Mock (NIP) and H2O2-treatment vs Mock (NIP).
Project description:Oxidative stress due to endogenous hydrogen peroxide production by Lactobacillus species is a well-known issue in the food industry. In this study, the transcriptional response to oxygen of Lactobacillus johnsonii, one of the H2O2-producing strains used in the food industry, was analyzed. It was found that aerobic growth conditions led to a more than two-fold downregulation of 45 genes as compared to anaerobic growth, whereas 6 genes were more than twofold upregulated. Among the upregulated genes were two genes that displayed significant homology to NADH-dependent oxidoreductase (NOX). The postulated transcriptional regulation of the nox promoter by oxygen was studied using a GUS-reporter construct, confirming a 2.1-fold upregulated GUS-expression upon aerobic growth. Exposure to sublethal levels of hydrogen peroxide did not result in significant regulation of the nox promoter. In a previous study of hydrogen peroxide production by L. johnsonii, a NADH flavin reductase (NFR) was identified to be involved in hydrogen peroxide production. An NFR-deficient derivative was strongly impaired in H2O2 production, but regained a partial H2O2 producing capacity upon prolonged oxygen exposure. The nox-promoter appeared to be 3.6-fold upregulated under aerobic conditions in the NFR-deficient background, which may imply a role of this gene in the regained H2O2 production. Indeed, deletion of the nox-gene in the NFR-deletion background, resulted in a strain that no longer produced H2O2, also during prolonged exposure to oxygen. The double-mutant (nfr, nox) displayed strongly impaired aerobic growth and oxygenation induced rapid growth stagnation that is not caused by H2O2. We conclude that H2O2 production in L. johnsonii is primarily dependent on NFR but can also involve an oxygen-inducible NADH oxidase under aerobic conditions. Moreover, our results imply that H2O2 production plays a prominent role in oxygen tolerance of L. johnsonii.
Project description:rs04-10_oxydative--stress - time course h2o2 treatment - Effect of an hydrogen peroxide treatment on gene regulation in arabidopsis cells - Arabidopsis cells (5 days after subculturing) were cultured at 21degreeC, 8 h photoperiod under agitation. H2O2 2.5 uM was added to cells 5 days after subculturing and 2 hours after the beginning of the light period. Treated and control cells were collected 15 min, 1 h, 5 h and 12 h after treatment. Keywords: treated vs untreated comparison
Project description:Oxidative stress due to endogenous hydrogen peroxide production by Lactobacillus species is a well-known issue in the food industry. In this study, the transcriptional response to oxygen of Lactobacillus johnsonii, one of the H2O2-producing strains used in the food industry, was analyzed. It was found that aerobic growth conditions led to a more than two-fold downregulation of 45 genes as compared to anaerobic growth, whereas 6 genes were more than twofold upregulated. Among the upregulated genes were two genes that displayed significant homology to NADH-dependent oxidoreductase (NOX). The postulated transcriptional regulation of the nox promoter by oxygen was studied using a GUS-reporter construct, confirming a 2.1-fold upregulated GUS-expression upon aerobic growth. Exposure to sublethal levels of hydrogen peroxide did not result in significant regulation of the nox promoter. In a previous study of hydrogen peroxide production by L. johnsonii, a NADH flavin reductase (NFR) was identified to be involved in hydrogen peroxide production. An NFR-deficient derivative was strongly impaired in H2O2 production, but regained a partial H2O2 producing capacity upon prolonged oxygen exposure. The nox-promoter appeared to be 3.6-fold upregulated under aerobic conditions in the NFR-deficient background, which may imply a role of this gene in the regained H2O2 production. Indeed, deletion of the nox-gene in the NFR-deletion background, resulted in a strain that no longer produced H2O2, also during prolonged exposure to oxygen. The double-mutant (nfr, nox) displayed strongly impaired aerobic growth and oxygenation induced rapid growth stagnation that is not caused by H2O2. We conclude that H2O2 production in L. johnsonii is primarily dependent on NFR but can also involve an oxygen-inducible NADH oxidase under aerobic conditions. Moreover, our results imply that H2O2 production plays a prominent role in oxygen tolerance of L. johnsonii. loop design of the samples including two shortcuts