Project description:The soil-borne bacterial pathogen Ralstonia solanacearum invades a broad range of plants through roots, resulting in wilting of the plant, but no effective protection against this disease has been developed. Two R. solanacearum resistance-inducing compounds were biochemically isolated from tobacco and identified as sclareol and cis-abienol, diterpenes. When exogenously applied to their roots, these diterpenes induced resistance to R. solanacearum in tobacco, tomato, and Arabidopsis plants without exhibiting any antimicrobial activity. Structure-activity correlation analysis of sclareol-related compounds revealed that the hydroxyl group at the eighth carbon position is responsible for the activity for inducing resistance. Microarray analysis identified many sclareol-responsive Arabidopsis genes, such as those encoding or with role in ABC transporters, biosynthesis and signaling of defense-related signal molecules, and mitogen-activated protein kinase (MAPK) cascades. Sclareol-induced R. solanacearum resistance was partially compromised in Arabidopsis mutants defective in the ABC transporter AtPDR12, the MAPK MPK3, and ethylene and abscisic acid signaling pathways. Transgenic tobacco plants in which NtPDR1, a tobacco homolog of AtPDR12, was silenced exhibited also reduced resistance. These results suggest that multiple host factors are involved in resistance to R. solanacearum induced by sclareol and its related compounds and that these compounds can be used to protect crops from bacterial wilt disease.
Project description:The soil-borne bacterial pathogen Ralstonia solanacearum invades a broad range of plants through roots, resulting in wilting of the plant, but no effective protection against this disease has been developed. Two R. solanacearum resistance-inducing compounds were biochemically isolated from tobacco and identified as sclareol and cis-abienol, diterpenes. When exogenously applied to their roots, these diterpenes induced resistance to R. solanacearum in tobacco, tomato, and Arabidopsis plants without exhibiting any antimicrobial activity. Structure-activity correlation analysis of sclareol-related compounds revealed that the hydroxyl group at the eighth carbon position is responsible for the activity for inducing resistance. Microarray analysis identified many sclareol-responsive Arabidopsis genes, such as those encoding or with role in ABC transporters, biosynthesis and signaling of defense-related signal molecules, and mitogen-activated protein kinase (MAPK) cascades. Sclareol-induced R. solanacearum resistance was partially compromised in Arabidopsis mutants defective in the ABC transporter AtPDR12, the MAPK MPK3, and ethylene and abscisic acid signaling pathways. Transgenic tobacco plants in which NtPDR1, a tobacco homolog of AtPDR12, was silenced exhibited also reduced resistance. These results suggest that multiple host factors are involved in resistance to R. solanacearum induced by sclareol and its related compounds and that these compounds can be used to protect crops from bacterial wilt disease. Genes that were preferentially expressed in Arabidopsis roots 2 hours after treatment with sclareol were explored. The microarray analysis was performed in triplicate.
Project description:This SuperSeries is composed of the following subset Series: GSE17517: Microarray analysis of high Arctic soil bacterial response to hydrocarbon pollution and bioremediation GSE17532: RT-PCR analysis of high Arctic soil bacterial response to hydrocarbon pollution and bioremediation Refer to individual Series
Project description:Here we have compared adult wildtype (N2) C. elegans gene expression when grown on different bacterial environments/fod sources in an effort to model naturally occuring nematode-bacteria interactions at the Konza Prairie. We hypothesize that human-induced changes to natural environments, such as the addition of nitrogen fertalizer, have effects on the bacterial community in soils and this drives downstream changes in the structure on soil bacterial-feeding nematode community structure. Here we have used transcriptional profiling to identify candidate genes involved in the interaction of nematodes and bacteria in nature.
Project description:Purpose: Molecular analysis of chickpea-Foc interaction; Methods: Four LongSAGE libraries of wilt-resistant and wilt-susceptible chickpea cultivars prepared after Foc inoculation and sequenced using Ion Torrent PGM. Results: Transcriptome analyses revealed expression of several plant defense and pathogen virulence genes with their peculier expression patterns in wilt-resistant and wilt-susceptible chickpea cultivars. Conclusion: The study identified several candidate Foc resistant genes, which can be used for crop improvement after their functional validation.
Project description:Bacterial wilt caused by Ralstonia solanacearum is a lethal, soil-borne disease of tomato. Control of the disease with chemicals and crop rotation is insufficient, because the pathogen is particularly well adapted for surviving in the soil and rhizosphere. Therefore, cultivar resistance is the most effective means for controlling bacterial wilt, but the molecular mechanisms of resistance responses remain unclear. We used microarrays to obtain the characteristics of the gene expression changes that are induced by R. solanacearum infection in resistant cultivar LS-89 and susceptible cultivar Ponderosa.