Project description:Phloem localization of plant viruses is advantageous for acquisition by sap-sucking vectors but hampers host-virus protein interaction studies. In this study, Potato leafroll virus (PLRV)-host protein complexes were isolated from systemically infected potato, a natural host of the virus. Comparing two different co-immunoprecipitation support matrices coupled to mass spectrometry, we identified 44 potato proteins and one viral protein (P1) specifically associated with virus isolated from infected phloem. An additional 142 proteins interact in complex with virus at varying degrees of confidence. Greater than 80% of these proteins were previously found to form high confidence interactions with PLRV isolated from the model host Nicotiana benthamiana. Bioinformatics revealed that these proteins are enriched for functions related to plasmodesmata, organelle membrane transport, translation and mRNA processing. Our results show that model system proteomics experiments are extremely valuable for understanding protein interactions regulating infection in recalcitrant pathogens such as phloem-limited viruses.
Project description:Solanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseasesas bacterial, fungal wilts and root-knot nematodes. A 30,0000 features custom combimatrix chip was designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples. We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena.The genes identified from S. torvum catalogue, bearing high homology to knownnematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism. total RNA was extracted from control and 14 days post-infection (infection with root-knot nematode Meloidogyne incognita) from roots of Solanum torvum and Solanum melongena. Three biological replicates were used for each condition and genotype for a total of 12 samples.
Project description:In this study a comparison was made between the local transcriptional changes at two time points upon root knot (Meloidogyne graminicola) and migratory nematode (Hirschmanniella oryzae) infection in rice. Using mRNA-Seq we have characterized specific and general responses of the root challenged with these endoparastic root nematodes with very different modes of action. Root knot nematodes induce major developmental reprogramming of the root tip, where they force the cortical cells to form multinucleate giant cells, resulting in gall-development. Our results show that root knot nematodes force the plant to produce and transfer nutrients, like sugars and amino acids, to this tissue. Migratory nematodes, on the other hand, induce the expression of proteins involved in plant death and oxidative stress, and obstruct the normal metabolic activity of the root. While migratory nematode infection also causes upregulation of biotic stress-related genes early in the infection, the root knot nematodes seem to actively suppress the local defence of the plant root. This is exemplified by a downregulation of genes involved in the salicylic acid and ethylene pathways. Interestingly, hormone pathways usually involved in plant development, were strongly induced (auxin and gibberellin) or repressed (cytokinin) in the galls. In addition, thousands of novel transcriptionally active regions as well as highly expressed nematode transcripts were detected in the infected root tissues. These results uncover previously unrecognized nematode-specific expression profiles and provide an interesting starting point to study the physiological function of many yet unannotated transcripts potentially targeted by these nematodes.
Project description:During a compatible interaction, root-knot nematodes (Meloidogyne spp.) induce the redifferentiation of root cells into multinucleate nematode feeding cells giant cells. These hypertrophied cells result from repeated nuclear divisions without cytokinesis, are metabolically active and present features typical of transfer cells. Hyperplasia of the surrounding cells leads to formation of the typical root gall. We investigate here the plant response to root-knot nematodes.
Project description:In this study a comparison was made between the local transcriptional changes at two time points upon root knot (Meloidogyne graminicola) and migratory nematode (Hirschmanniella oryzae) infection in rice. Using mRNA-Seq we have characterized specific and general responses of the root challenged with these endoparastic root nematodes with very different modes of action. Root knot nematodes induce major developmental reprogramming of the root tip, where they force the cortical cells to form multinucleate giant cells, resulting in gall-development. Our results show that root knot nematodes force the plant to produce and transfer nutrients, like sugars and amino acids, to this tissue. Migratory nematodes, on the other hand, induce the expression of proteins involved in plant death and oxidative stress, and obstruct the normal metabolic activity of the root. While migratory nematode infection also causes upregulation of biotic stress-related genes early in the infection, the root knot nematodes seem to actively suppress the local defence of the plant root. This is exemplified by a downregulation of genes involved in the salicylic acid and ethylene pathways. Interestingly, hormone pathways usually involved in plant development, were strongly induced (auxin and gibberellin) or repressed (cytokinin) in the galls. In addition, thousands of novel transcriptionally active regions as well as highly expressed nematode transcripts were detected in the infected root tissues. These results uncover previously unrecognized nematode-specific expression profiles and provide an interesting starting point to study the physiological function of many yet unannotated transcripts potentially targeted by these nematodes. 2 or 3 biological replicates of nematode infected roots and root tips and their respective controls were sampled at two time points (1 biological replicate contains pooled tissue from 6 plants)
Project description:The aim of this study was to elucidate the molecular basis underlying the compatible interaction between potato and root-knot nematode at early stages on infection at 3 and 7dpi.
Project description:Solanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseasesas bacterial, fungal wilts and root-knot nematodes. A 30,0000 features custom combimatrix chip was designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples. We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena.The genes identified from S. torvum catalogue, bearing high homology to knownnematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism.
Project description:Purpose: MicroRNAs (miRNAs) are ubiquitous components of endogenous plant transcriptome. miRNAs are small, single-stranded and ~21 nt long RNAs which regulate gene expression at the post-transcriptional level and are known to play essential roles in various aspects of plant development and growth. Previously, a number of miRNAs have been identified in potato through in silico analysis and deep sequencing approach. However, identification of miRNAs through deep sequencing approach was limited to a few tissue types and developmental stages. This study reports the identification and characterization of potato miRNAs in three different vegetative tissues and four stages of tuber development by high throughput sequencing. Results: Small RNA libraries were constructed from leaf, stem, root and four early developmental stages of tuberization and subjected to deep sequencing, followed by bioinformatics analysis. A total of 89 conserved miRNAs (belonging to 33 families), 147 potato-specific miRNAs (with star sequence) and 112 candidate potato-specific miRNAs (without star sequence) were identified. The digital expression profiling based on TPM (Transcripts Per Million) and qRT-PCR analysis of conserved and potato-specific miRNAs revealed that some of the miRNAs showed tissue specific expression (leaf, stem and root) while a few demonstrated tuberization stage-specific expressions. Targets were predicted for identified conserved and potato-specific miRNAs, and predicted targets of four conserved miRNAs, miR160, miR164, miR172 and miR171, which are ARF16 (Auxin Response Factor 16), NAM (NO APICAL MERISTEM), RAP1 (Relative to APETALA2 1) and HAIRY MERISTEM (HAM) respectively, were experimentally validated using 5′RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends). Gene ontology (GO) analysis for potato-specific miRNAs was also performed to predict their potential biological functions. Conclusions: We report a comprehensive study of potato miRNAs at genome-wide level by high-throughput sequencing and demonstrate that these miRNAs have tissue and/or developmental stage specific expression profile. Also, predicted targets of conserved miRNAs were experimentally confirmed for the first time in potato. Our findings indicate the existence of extensive and complex small RNA population in this crop and suggest their important role in pathways involved in diverse biological processes, including tuber developmental process.