Project description:Arabidopsis thaliana plants were infested i) with sucking insect herbivores (the generalist aphid Myzus persicae and the specialist aphid Brevicoryne brassicae), ii) with chewing insect herbivores (generalist caterpillars of Spodoptera exigua and specialist caterpillars of Pieris rapae) or iii) were treated by wounding. For each treatment, rosette leaves were harvested at two time points (6h and 24h) after removal of insects. For chewing herbivores and wounding both local, i.e. immediately damaged leaves, and systemic, i.e. undamaged leaves from the same plant, were collected. Control plants were uninfested, but otherwise equally treated and harvested in parallel. We tested the hypothesis that Arabidopsis can recognize and respond differentially to insect species at the transcriptional level using a genome wide microarray. Transcriptional reprogramming was characterized using co-expression analysis in damaged and undamaged leaves at two times in response to mechanical wounding and four insect species. In all, 2778 (10.6%) of annotated genes on the array were differentially expressed in at least one treatment. Responses differed mainly between aphid and caterpillar and sampling times. Responses to aphids and caterpillars shared only 10% of up-regulated and 8% of down-regulated genes. Responses to two caterpillars shared 21% and 12% of up- and down-regulated genes, whereas responses to the two aphids shared only 7% and 4% of up-regulated and down-regulated genes. Overlap in genes expressed between 6h and 24h was 3-15%, and depended on the insect species. Responses in attacked and unattacked leaves differed at 6h but converged by 24h. Genes responding to the insects are also responsive to many stressors and included primary metabolism. Aphids down-regulated amino acid catabolism; caterpillars stimulated production of amino acids involved in glucosinolate synthesis. Co-expression analysis revealed 17 response networks. Transcription factors were a major portion of differentially expressed genes throughout and responsive genes shared most of the known or postulated binding sites.
Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. We identified wound-inducible genes by comparison with transcriptomes between wounded and untreated wild-type rice leaves.
Project description:In order to find out whether insects are suitable as a pure protein source and what potential problems or benefits can be expected, a 10-week feeding experiment was set up. In this experiment, the overall protein content were identical, while the protein content from soy and fishmeal was replaced with 25, 50, 75 and 100% insect meal. In order to evaluate the effect of the insect protein on the fish, fish size and weight were determined at the beginning and end of the experiment, and transcriptomic analyses of proximal intestine were performed. Finally, samples of the liver and intestine were examined histologically.
Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. We identified wound-inducible genes by comparison with transcriptomes between wounded and untreated wild-type rice leaves. Expression profiling in wild-type rice leaves treated by wounding for 0.5, 1, 2 and 4 h was compared with that in untreated control using two-color method with two biological replicates.
Project description:Head smut of maize, which is caused by the Sporisorium reilianum f. sp. Zeae (Kühn), has been a serious disease in maize. In order to find head smut resistant candidate genes, microarrays were used to monitor the gene expression profiles between disease resistant near isogenic lines (NIL) L282 and L43, highly resistant inbred line Q319 and highly susceptible inbred line Huangzao4 after 0 to7 days post inoculation of S.reiliana by artificial inoculation method. Maize leaves were selected at 0d, 1d, 2d, 4d, 7d post inoculation for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain different expression genes of different varieties at each inoculation stage in order to find head smut resistant candidate genes.
Project description:Three different maize lines were assayed for differential gene expression in mature leaf tissue. Leaves from the Oh43 maize line are more resistant to insect larvae damage than the original parents, lines Oh40B and W8. The goal of the project was to discover genes highly expressed in the Oh43 line that potentially contributes to insect resistance.
Project description:Insect pathogenic fungus Beauveria bassiana in one of the best studied insect biocontrol fungus, which infects insects by cuticle penetration. After breaking the cuticles, the fungus will propagate in insect hemocoel and kill insect hosts. It has also been found that the mycelia of B. bassiana can penetrate plant tissues to reach insect inside plant, e.g. corn borer (Ostrinia furnacalis), but do not cause damage to plants. The mechanism of fungal physiological plasticity is poorly understood. To accompany our genome sequencing work of B. bassiana strain ARSEF 2860, fungal transcriptional responses to different niches were studied using an Illumina RNA_seq technique. To examine fungal response to insect cuticle, conidia were inoculated on locust hind wings for 24 hours before used for RNA extraction. To evaluate fungal adaptation to insect hemocole, the fifth instar larvae of cotton bollworms were injected with spore suspension and fungal cells isolated by centrifugation in a step gradient buffer. To unveil the mechanism of interaction with plants, the fungus was grown in corn root exudates for 24 hours. After RNA sequencing, around three million tags were acquired for each sample and fungal transcriptional profiles were compared.