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:Investigation of whole genome gene expression level changes in the bacterial wilt pathogen Ralstonia solanacearum, strain GMI1000 at 20°C and 28°C in culture and in planta. The tropical strain GMI1000 cannot wilt tomato plants at 20°C although it can cause full-blown disease at 28°C.
Project description:Investigation of whole genome gene expression level changes in the bacterial wilt pathogen Ralstonia solanacearum, strain UW551 at 20°C and 28°C in culture and in planta. The temperatel strain UW551 can wilt and cause full-blown disease on tomato plants at 28°C as well as at 20°C.
2012-01-15 | GSE33661 | GEO
Project description:Bacillus velezensis B4-7 for the biocontrol of tobacco bacterial wilt
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.
Project description:We found the Type III effector protein RipAB could suppress multiple plant immune responses and is important for the virulence of bacterial wilt pathogen Ralstonia solanacearum.
Project description:Ralstonia solanacearum causes disease in more than 200 plant species including bacterial wilt of tomatoes and brown rot of potatoes. This bacterium is a soilborne and waterborne pathogen, with a worldwide distribution and is on the EPPO A2 list of quarantine pathogens. ln the UK, the bacterium is present in the rivers, but its prevalence depends on the season; it is highly abundant in the summer and undetectable during winter. To survive the cold winter temperatures, R. solanacearum overwinters inside plants growing alongside the rivers such as Solanum dulcamara. Interestingly, this plant species doesn’t show bacterial wilt symptoms. To understand genomic differences with susceptible hosts, we assembled the genome using Oxford Nanopore Technologies and Illumina sequencing.