Limits...
Transcriptional responses of Arabidopsis thaliana to chewing and sucking insect herbivores.

Appel HM, Fescemyer H, Ehlting J, Weston D, Rehrig E, Joshi T, Xu D, Bohlmann J, Schultz J - Front Plant Sci (2014)

Bottom Line: However, cis-element composition of genes down regulated by the aphid M. persicae was unique, as were those of genes down-regulated by caterpillars.As many as 20 cis-elements were over-represented in one or more treatments, including some from well-characterized classes and others as yet uncharacterized.We suggest that transcriptional changes elicited by wounding and insects are heavily influenced by transcription factors and involve both enrichment of a common set of cis-elements and a unique enrichment of a few cis-elements in responding genes.

View Article: PubMed Central - PubMed

Affiliation: Bond Life Sciences Center and Division of Plant Sciences, University of Missouri Columbia, MO, USA.

ABSTRACT
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 6 and 24 h was 3-15%, and depended on the insect species. Responses in attacked and unattacked leaves differed at 6 h but converged by 24 h. 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. However, cis-element composition of genes down regulated by the aphid M. persicae was unique, as were those of genes down-regulated by caterpillars. As many as 20 cis-elements were over-represented in one or more treatments, including some from well-characterized classes and others as yet uncharacterized. We suggest that transcriptional changes elicited by wounding and insects are heavily influenced by transcription factors and involve both enrichment of a common set of cis-elements and a unique enrichment of a few cis-elements in responding genes.

No MeSH data available.


Related in: MedlinePlus

Hierarchical cluster tree of A. thaliana genes differentially expressed in response to insect feeding and mechanical wounding. Abbreviations for treatment names are the same as those used in Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4231836&req=5

Figure 1: Hierarchical cluster tree of A. thaliana genes differentially expressed in response to insect feeding and mechanical wounding. Abbreviations for treatment names are the same as those used in Table 1.

Mentions: We assessed the transcriptional responses in rosette leaves of 4-week-old A. thaliana Col plants to artificial wounding, attack by larvae of two species of leaf chewing caterpillar species and by adults and nymphs of two phloem feeding aphid species (Table 1). In all, 2778 genes on the full genome wide array were differentially expressed in one or more of our treatments, representing approximately 10.6% of the genes on the array having AGI annotation (Supplemental Table 2). Hierarchical clustering based on similarities (correlations) among the resulting transcriptional profiles (Figure 1) revealed three major clusters, one containing all aphid treatments, a second comprising wounding plus caterpillar treatments at 24 h, and the third comprising wounding plus caterpillar treatments at 6 h. The aphid cluster contained two subclusters based on sampling time. The wounding plus caterpillar cluster divided into two subclusters, one for wounding and another for the two caterpillar species; the latter contained sub subclusters for each species. The third cluster, responses to wounding and caterpillars at 6 h, divided into two subclusters, one for wounding and another for the insects, with the insect sub subcluster further divided by species. Hence feeding type (sucking vs. chewing) and sampling time (6 and 24 h) contributed most (about 40–60% of variance explained) to differentiating the transcriptional response profiles, whereas species contributed some (about 20% of variance explained) to differentiation and tissue treatment (wounded or not) contributed least (<10% of the variance) (Figure 1).


Transcriptional responses of Arabidopsis thaliana to chewing and sucking insect herbivores.

Appel HM, Fescemyer H, Ehlting J, Weston D, Rehrig E, Joshi T, Xu D, Bohlmann J, Schultz J - Front Plant Sci (2014)

Hierarchical cluster tree of A. thaliana genes differentially expressed in response to insect feeding and mechanical wounding. Abbreviations for treatment names are the same as those used in Table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231836&req=5

Figure 1: Hierarchical cluster tree of A. thaliana genes differentially expressed in response to insect feeding and mechanical wounding. Abbreviations for treatment names are the same as those used in Table 1.
Mentions: We assessed the transcriptional responses in rosette leaves of 4-week-old A. thaliana Col plants to artificial wounding, attack by larvae of two species of leaf chewing caterpillar species and by adults and nymphs of two phloem feeding aphid species (Table 1). In all, 2778 genes on the full genome wide array were differentially expressed in one or more of our treatments, representing approximately 10.6% of the genes on the array having AGI annotation (Supplemental Table 2). Hierarchical clustering based on similarities (correlations) among the resulting transcriptional profiles (Figure 1) revealed three major clusters, one containing all aphid treatments, a second comprising wounding plus caterpillar treatments at 24 h, and the third comprising wounding plus caterpillar treatments at 6 h. The aphid cluster contained two subclusters based on sampling time. The wounding plus caterpillar cluster divided into two subclusters, one for wounding and another for the two caterpillar species; the latter contained sub subclusters for each species. The third cluster, responses to wounding and caterpillars at 6 h, divided into two subclusters, one for wounding and another for the insects, with the insect sub subcluster further divided by species. Hence feeding type (sucking vs. chewing) and sampling time (6 and 24 h) contributed most (about 40–60% of variance explained) to differentiating the transcriptional response profiles, whereas species contributed some (about 20% of variance explained) to differentiation and tissue treatment (wounded or not) contributed least (<10% of the variance) (Figure 1).

Bottom Line: However, cis-element composition of genes down regulated by the aphid M. persicae was unique, as were those of genes down-regulated by caterpillars.As many as 20 cis-elements were over-represented in one or more treatments, including some from well-characterized classes and others as yet uncharacterized.We suggest that transcriptional changes elicited by wounding and insects are heavily influenced by transcription factors and involve both enrichment of a common set of cis-elements and a unique enrichment of a few cis-elements in responding genes.

View Article: PubMed Central - PubMed

Affiliation: Bond Life Sciences Center and Division of Plant Sciences, University of Missouri Columbia, MO, USA.

ABSTRACT
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 6 and 24 h was 3-15%, and depended on the insect species. Responses in attacked and unattacked leaves differed at 6 h but converged by 24 h. 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. However, cis-element composition of genes down regulated by the aphid M. persicae was unique, as were those of genes down-regulated by caterpillars. As many as 20 cis-elements were over-represented in one or more treatments, including some from well-characterized classes and others as yet uncharacterized. We suggest that transcriptional changes elicited by wounding and insects are heavily influenced by transcription factors and involve both enrichment of a common set of cis-elements and a unique enrichment of a few cis-elements in responding genes.

No MeSH data available.


Related in: MedlinePlus