Project description:Magnaporthe oryzae (rice blast) and the root-knot nematode Meloidogyne graminicola are causing two of the most important pathogenic diseases jeopardizing rice production. Here, we show that root-knot nematode infestation on rice roots leads to important above-ground changes in plant immunity gene expression, which is correlated with significantly enhanced susceptibility to blast disease.
Project description:Transcriptome expression analysis in peanut to date has been limited to a relatively small set of genes and only recently have moderately significant number of ESTs has been released into the public domain. Utilization of these ESTs for the oligonucleotide microarrays provides a means to investigate large-scale transcript responses to a variety of developmental and environmental signals, ultimately improving our understanding of plant biology. We have developed a high-density oligonucleotide microarray for peanut using approximately 47,767 publicly available ESTs and tested the utility of this array for expression profiling in a variety of peanut tissues. To identify putatively tissue-specific genes and investigate the utility of this array, we compared transcript levels in pod to peg, leaf, stem, and root tissues. Results from this experiment showed a number of putatively pod-specific/abundant genes, as well as transcripts whose expression was low or undetected in pod compared to either peg, leaf, or stem. Keywords: Peanut tissue-specific gene expression We used Agilent peanut gene chips (017430) to identify putative tissue-specific genes and investigate the utility of the array for expression profiling of various peanut tissues. Pod, leaf, stem, peg and root tissues of the peanut genotype Flavrunner 458 were used in the study. Field grown plants under normal irrigation were used for sample collection. Three replications of microarray experiments were carried out by hybridizing the cRNA from pod tissue and cRNA from leaf, stem, peg and root tissues on the same dual color oligonucleotide arrays.
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: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.
Project description:Transcriptome expression analysis in peanut to date has been limited to a relatively small set of genes and only recently have moderately significant number of ESTs has been released into the public domain. Utilization of these ESTs for the oligonucleotide microarrays provides a means to investigate large-scale transcript responses to a variety of developmental and environmental signals, ultimately improving our understanding of plant biology. We have developed a high-density oligonucleotide microarray for peanut using approximately 47,767 publicly available ESTs and tested the utility of this array for expression profiling in a variety of peanut tissues. To identify putatively tissue-specific genes and investigate the utility of this array, we compared transcript levels in pod to peg, leaf, stem, and root tissues. Results from this experiment showed a number of putatively pod-specific/abundant genes, as well as transcripts whose expression was low or undetected in pod compared to either peg, leaf, or stem. Keywords: Peanut tissue-specific gene expression
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.