Project description:MicroRNAs (miRNAs) are a class of endogenous non-coding small RNAs that regulate targeted mRNAs by degrading or repressing translation, considered as post-transcrption regulators. So far, a large number of miRNAs have been discovered in model plants, but little information is available on miRNAs in banana. In this study, by sequencing the small RNA (sRNA) transcriptomes of Fusarium wilt resistant and susceptible banana varieties, 139 members in 38 miRNA families were discovered, and six out of eight new miRNAs were confirmed by RT-PCR. According to the analysis of sRNA transcriptome data and qRT-PCR verification, some miRNAs were differentially expressed between Fusarium wilt resistant and susceptible banana varieties. Two hundred and ninety-nine and 31 target genes were predicted based on the draft maps of banana B genome and Fusarium oxysporum (FOC1, FOC4) genomes respectively. Specifically, two important pathogenic genes in Fusarium oxysporum genomes, feruloyl esterase gene and proline iminopeptidase gene, were targeted by banana miRNAs. These novel findings may provide a new strategy for the prevention and control of Fusarium wilt in banana.
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: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: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.
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 are requesting the polar metabolomics analysis from a high-resolution time series experiment to develop probabilistic graphical models of bacterial-fungal-plant interactions. The experiment exposed resistant (line H7996) and susceptible (line FL8000) tomatoes (Solanum lycopersicum) to the select agent soil pathogen Ralstonia solanacearum (RS5) which is responsible for Bacterial Wilt. R. solanacearum infects plants through root wounds and colonizes vascular tissues. The pathogen rapidly multiplies and clogs the xylem vessels causing the infected plant to quickly wilt and die. Exopolysaccharides from R. solanacearum activate salicylic acid (SA) pathways in the resistant plants, but not in susceptible plants (Mansfield et al., 2012; Milling et al., 2011). A recent study suggested the microbiome plays a role in host susceptibility (Kwak et al., 2018). The system is being used as a model for developing new techniques in modeling bacterial-fungal-plant interactions and developing statistical methods to engineer microbial consortia from these graphical models.
The work (proposal:httpas://doi.org/10.46936/10.25585/60000455) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
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.
Project description:Banana xylem sap contained defense-related proteins, among which HIRP1, E3, CHI, GRP, CXE and GLIP involved in banana defense against TR4. To our knowledge, this is first report to analyze changes in banana xylem sap proteins response to TR4, which help us to explore molecular mechanisms of banana resistant to Fusarium wilt.
Project description:Ralstonia solanacearum, recognized as a pervasive plant pathogen causing lethal wilt disease in over 450 plant species worldwide, represents a substantial threat to economically vital crops including tomato, chili, and eggplant. Within R. solanacearum, pehR serves as a transcriptional regulator, forming part of the pehSR two-component regulatory system. This system governs the production of polygalacturonase (PG), a crucial extracellular enzyme involved in plant cell wall degradation and bacterial wilt development. Our study focuses on a disruption mutant of the pehR gene from the local isolate R. solanacearum F1C1, obtained from Tezpur, Assam. Utilizing RNA-seq, we examine the gene expression profiles of R. solanacearum F1C1 under pehR regulation. Differential expression analysis between wild type and pehR mutants reveals a set of genes directly influenced by pehR. This comprehensive gene expression analysis provides insights into the system-level responses orchestrated by the pehR regulator in pathogenicity and virulence development. Moreover, it sheds light on the broader regulatory network controlled by pehR and its underlying molecular mechanisms. Our work also underscores the identification of key target genes regulated by pehR within R. solanacearum F1C1, offering a deeper understanding of its role in bacterial pathogenicity. Ultimately, unraveling the complete pehR regulome holds promise for elucidating the regulatory dynamics driving the pathogenic behavior of R. solanacearum F1C1.
Project description:Background: Banana (Musa) is one of the most important crops grown in tropical and sub-tropical areas. Cavendish, the most widely grown banana cultivar, is a triploid derived from an intra-species cross. Cavendish is relatively resistant to Race 1 of Fusarium oxysporum f. sp. Cubense (Foc1) which caused wide spread Panama disease during 1960s but is susceptible to Race 4 of Foc (Foc4) which has been causing epidemics in large areas of banana fields in Asia and Australia in the last decade and is threatening world banana production. The genome of the diploid species Musa acuminata (AA) which is the ancestor of a majority of cultivated banana has recently been sequenced. Availability of banana transcriptomes will be highly useful for improving banana genome annotation and assembly and for banana biological research. The knowledge of global gene expression patterns influenced by infection by different Foc races will help to understand the pathogenesis processes and the host responses to the infection. Results: RNA samples extracted from different organs of the Cavendish cultivar were pooled for deep sequencing using the Illumina sequencing technology. The assembled reads were aligned with the genome of M. accuminata and with sequences in the Genbank databases. The analysis led to identification of 842 genes that were not annotated by the Musa genome project. A large number of simple nucleotide polymorphisms (SNPs) and short insertions and deletion (indels) were identified from the transcriptome data. GFP-expressing Foc1 and Foc4 was generated and used to monitor the infection process. Digital gene expression (DGE) profiling analysis was carried out to obtain transcriptome profiles influenced by infection with Foc1 and Foc4 in banana roots at 3, 27, and 51 hours post-inoculation. Both Foc1 and Foc4 were found to be able to invade banana roots and spread to root vascular tissues in the first two days following inoculation. The profiling analysis revealed that inoculation with Foc1 and Foc4 caused similar changes in the gene expression profiles in the infected banana roots. The Foc infection led to induction of many well-known defense-related genes including PATHOGENESIS-RELATED 5 (PR5), PAL, and a lignin-forming peroxidase. The WRKY40 gene, which is a negative regulator of the defense pathway in Arabidopsis, was quickly and strongly suppressed by the infection. Two genes encoding the ethylene biosynthetic enzyme ACC oxidase and several ethylene-responsive transcription factors were among strongly induced genes by both Foc1 and Foc4 Conclusions: Both Foc1 and Foc4 are able to spread into the vascular system of banana roots during the first two days of the infection process and their infection led to similar gene expression profiles in banana roots. The transcriptome profiling analysis indicates that the ethylene synthetic and signalling pathways were activated in response to the Foc infection. Digital gene expression (DGE) profiling analysis was carried out to obtain transcriptome profiles influenced by infection with Foc1 and Foc4 in banana roots at 3, 27, and 51 hours post-inoculation. The plants whose roots were immersed in the culture medium without the pathogen (mock inoculation) were used as a control.