Project description:Nitric oxide (NO.) is a well-established signal in mammalian cells regulating e.g. smooth muscle tone, neurotransmission and apoptosis. NO interacts with superoxide (O2-) to derive the highly reactive peroxynitrite (ONOO-) radical leading to the generation of lipid hydroxy-peroxides (ROO.) and cell death. Thus the recent reports implicating of .NO in the Hypersensitive Response (HR) a form of programmed cell death elicited by pathogens in plantsis suggestive of parallel roles in animals and plants. As part of BBSRC funded programmes which are investigating oxidative signaling and cell death in Arabidopsis we have collaborated with the Trace Gas Detection facility at the University of Nijmegen to be the first to measure NO in planta from a developing HR (Mur et al.paper in prep). The challenge remains to understand the spatio-temporal role(s) of .NO during the HR and disease development. In line with other groups e.g. Klessig et al.(2000) PNAS 978849-55 we have observed that .NO mediated event are both SA- dependent and independent. We propose a two-stage programme to investigate NO events which will lead to subsequent BBSRC grant bids. Firstly to exploit the GARNET Affymetrix transcriptomic service to identify genes which are upregulated by .NO (see programme below). These will be compared with similar data generated by other members of the consortium; Dr. Steve Neill for oxidative stress (Desikan et al. (2001). Plant Physiol 127(1): 159-72; Clarke et al.2000 Plant J.; 24:667-77); Dr. Paul Kenton who is mainly interested in signaling by the oxylipid Jasmonic acid (Kentonet al. (1999). MPMI 12(1): 74-78) as well as from other sources. Though these data in themselves will suggest modes of NO action. However as a second approach we will clone the promoter of a strongly NO-responsive gene which will be fused to positive and negative selectable markers as well as reporter genes e.g. LUC. to identify Arabidopsis EMS mutants which are perturbed in NO-mediated events. Programme. Our in planta measurement show that from a baseline production of 1nl.g fwt-1h-1 NO levels rise to 6nl. g fwt-h-1 (_plus/- 1.1 SE) prior to cell death and to 25nl g fwt-h-1 (_plus/- 4.2 SE) at cell death following which the concentration falls. At this juncture we will intend to gas Arabidopsis to ~75ppb (the head-space concentration when NO production was at 6nl. g fwt-h-1). Prior to using the DNA RNA will establish that this does not elicit cell death over the proposed treatment period and that both PR1 (SA-dependent) and PAL1 (SA-independent) genes are induced. We will compare this plant with sealed but non-treated Arabidopsis. Future targets for DNA RNAs analysis induce plant treated with both NO (Sodium Nitro Prusside) and O2- (Xanthine oxidase) generators and depending on their effectiveness (to be assessed by NO measurement) HR lesions treated with Nitric Oxide Synthase inhibitors. Keywords: compound_treatment_design

Project description:Nitric oxide (NO.) is a well-established signal in mammalian cells regulating e.g. smooth muscle tone, neurotransmission and apoptosis. NO interacts with superoxide (O2-) to derive the highly reactive peroxynitrite (ONOO-) radical leading to the generation of lipid hydroxy-peroxides (ROO.) and cell death. Thus the recent reports implicating of .NO in the Hypersensitive Response (HR) a form of programmed cell death elicited by pathogens in plantsis suggestive of parallel roles in animals and plants. As part of BBSRC funded programmes which are investigating oxidative signaling and cell death in Arabidopsis we have collaborated with the Trace Gas Detection facility at the University of Nijmegen to be the first to measure NO in planta from a developing HR (Mur et al.paper in prep). The challenge remains to understand the spatio-temporal role(s) of .NO during the HR and disease development. In line with other groups e.g. Klessig et al.(2000) PNAS 978849-55 we have observed that .NO mediated event are both SA- dependent and independent. We propose a two-stage programme to investigate NO events which will lead to subsequent BBSRC grant bids. Firstly to exploit the GARNET Affymetrix transcriptomic service to identify genes which are upregulated by .NO (see programme below). These will be compared with similar data generated by other members of the consortium; Dr. Steve Neill for oxidative stress (Desikan et al. (2001). Plant Physiol 127(1): 159-72; Clarke et al.2000 Plant J.; 24:667-77); Dr. Paul Kenton who is mainly interested in signaling by the oxylipid Jasmonic acid (Kentonet al. (1999). MPMI 12(1): 74-78) as well as from other sources. Though these data in themselves will suggest modes of NO action. However as a second approach we will clone the promoter of a strongly NO-responsive gene which will be fused to positive and negative selectable markers as well as reporter genes e.g. LUC. to identify Arabidopsis EMS mutants which are perturbed in NO-mediated events. Programme. Our in planta measurement show that from a baseline production of 1nl.g fwt-1h-1 NO levels rise to 6nl. g fwt-h-1 (_plus/- 1.1 SE) prior to cell death and to 25nl g fwt-h-1 (_plus/- 4.2 SE) at cell death following which the concentration falls. At this juncture we will intend to gas Arabidopsis to ~75ppb (the head-space concentration when NO production was at 6nl. g fwt-h-1). Prior to using the DNA RNA will establish that this does not elicit cell death over the proposed treatment period and that both PR1 (SA-dependent) and PAL1 (SA-independent) genes are induced. We will compare this plant with sealed but non-treated Arabidopsis. Future targets for DNA RNAs analysis induce plant treated with both NO (Sodium Nitro Prusside) and O2- (Xanthine oxidase) generators and depending on their effectiveness (to be assessed by NO measurement) HR lesions treated with Nitric Oxide Synthase inhibitors.

Dataset Information

Mode of nitric oxide delivery affects antibacterial action.

Publications

Mode of nitric oxide delivery affects antibacterial action.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets