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: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:BackgroundFusarium wilt, caused by Fusarium oxysporum f. sp. cubense race 4 (Foc4), is the most lethal disease of bananas in Asia.MethodsTo better understand the defense response of banana to Fusarium wilt, the transcriptome and metabolome profiles of the roots from resistant and susceptible bananas inoculated with Foc4 were compared.ResultsAfter Foc4 inoculation, there were 172 and 1,856 differentially expressed genes (DEGs) in the Foc4-susceptible variety (G1) and Foc4-resistant variety (G9), respectively. In addition, a total of 800 DEGs were identified between G1 and G9, which were mainly involved in the oxidation-reduction process, cell wall organization, phenylpropanoid biosynthesis, and lipid and nitrogen metabolism, especially the DEGs of Macma4_08_g22610, Macma4_11_g19760, and Macma4_03_g06480, encoding non-classical arabinogalactan protein; GDSL-like lipase; and peroxidase. In our study, G9 showed a stronger and earlier response to Foc4 than G1. As the results of metabolomics, lipids, phenylpropanoids and polyketides, organic acids, and derivatives played an important function in response to Fusarium wilt. More importantly, Macma4_11_g19760 might be one of the key genes that gave G9 more resistance to Foc4 by a lowered expression and negative regulation of lipid metabolism. This study illustrated the difference between the transcriptomic and metabolomic profiles of resistant and susceptible bananas. These results improved the current understanding of host-pathogen interactions and will contribute to the breeding of resistant banana plants.
Project description:BPH9 is a gene that confers rice strong resistance to its devastating pest BPH. Understanding the molecular responses of the resistant and susceptible varieties would pave the way to controlling the pest more effectively. To better understand the molecular mechanism underlying resistance to BPH mediated by BPH9, we conducted a genome-wide microarray analysis of NIL-BPH9 and 9311 at the early stage of BPH infestation.
Project description:Bph6 is a gene that confers rice high resistance to its devastating pest BPH. Understanding the molecular responses of the resistant and susceptible varieties would pave the way to controlling the pest more effectively. To better understand the molecular mechanism underlying resistance to BPH mediated by Bph6, we conducted a genome-wide microarray analysis of NIL-BPH9 and 9311 at the early stage of BPH infestation.
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:We carried out an RNA-seq based transcriptome study on two rice varieties, Cocodrie (CCDR; rice sheath blight susceptible) and MCR10277 (MCR; rice sheath blight resistant), to profile the time-series wide genome-scale transcriptional differences in response to sheath blight (SB), an infection caused by R. solanii (LR172) . Our approach is cross-referencing differentially expressed genes with significant variants of two phenotypically different varieties to validate known and discover novel variants and to further understand rice's physiological response to SB.
Project description:The soil-borne fungal pathogen Fusarium oxysporum f.sp. is responsible for Fusarium wilt. cubense tropical race 4, is one of the most devastating diseases in bananas, regarded as a major yield-reducing factor in the banana industry worldwide. Understanding the molecular interactions in banana defense responses is an important tool to reveal the unexplained processes that underlie banana resistance to Fusarium oxysporum f. sp. cubense tropical race 4. The seedlings of moderately resistant variety Guijiao No. 9 and a susceptible cultivar Guijiao No. 6 were cultured in tissue culture, and the characterize protein profile expression changes responses to after inoculation the Fusarium oxysporum f. sp. of cubense tropical race 4 were detected by isobaric labeling based on MS2 quantification at the 2nd, 4th, 6th and 8th day. Interestingly, new genes in the resistance of banana to Foc37-GFP were identified, including several other serine/threonine-protein kinase, AvrRpt-cleavage domain-containing protein, peptidylprolyl isomerase and some Jacalin-type lectin domain, the resistance-related pathways “ribosome”, “microbial metabolism in diverse environments”,“carbon metabolism”,“biosynthesis of amino acids”and “biosynthesis of antibiotics” pathways were significantly enriched, the resistant banana cultivar Guijiao 9 shows formation of different constitutive cell barriers to restrict spreading of Fusarium oxysporum f. sp. cubense tropical race 4. In this study, the dynamic change root proteomic of moderately resistant cultivar Guijiao 9 and a susceptible cultivar Guijiao 6 were characterized and provided a differentially expressed proteins comparative analysis of the compatible and incompatible interaction between Fusarium oxysporum f. sp. cubense tropical race 4 and banana. These findings provide a substantial contribution to existing sequence resources for banana, and a strong basis for future proteomic research. The proteins that displayed two-fold changes in intensity are related to biochemical processes that may be differentially altered at various times after Fusarium oxysporum f. sp. cubense tropical race 4 infection. These findings will accelerate research on resistance in banana to Fusarium oxysporum f. sp. cubense tropical race 4 and contribute to a better understanding of the banana defense mechanism to plant pathogens, hopefully.
Project description:Nitrogen (N) fertilisers are routinely applied to bananas (Musa spp.) to increase production, but may exacerbate important disease such as Fusarium wilt of banana (FWB). Here, we characterised the effects of N rate and form (ammonium or nitrate) on FWB severity, the banana root proteome, and the diversity of rhizosphere bacterial and fungal communities. Banana plants (Musa ABB) were grown under greenhouse conditions in soil with ammonium or nitrate supplemented at five N rates, and with or without inoculation with Fusarium oxysporum f. sp. cubense (Foc). The growth of non-inoculated plants was positively correlated with N rate. In bananas inoculated with Foc, disease severity increased with N rate, resulting in Foc-inoculated plant growth being greatest at intermediate N rates. The abundance of Foc was weakly related to the treatment conditions and was a poor predictor of disease severity. Fungal diversity was consistently affected by Foc inoculation, while bacterial diversity was associated with changes in soil pH resulting from N addition, in particular ammonium. N rate altered the expression of host metabolic pathways associated with carbon fixation, energy usage, amino acid metabolism, and importantly stress response signalling, irrespective of inoculation or N form. Furthermore, in diseased plants, Pathogenesis-related protein 1, a key endpoint for biotic stress response and the salicylic acid defence response to biotrophic pathogens, was negatively correlated with the rate of ammonium fertiliser but not nitrate. As expected, inoculation with Foc altered the expression of a wide range of processes in the banana plant including those of defence and growth. In summary, our results indicate that the severity of FWB was negatively associated with host defences, which were influenced by N application (particularly ammonium), and shifts in microbial communities in response to ammonium-induced acidification.
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.