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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

Treatment comparisons with the number of genes differentially expressed in each treatment, the number of genes expressed in both treatments, and their proportional overlap. Upward pointing arrows indicate upregulated genes, downward pointing arrows indicate downregulated genes.
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Figure 3: Treatment comparisons with the number of genes differentially expressed in each treatment, the number of genes expressed in both treatments, and their proportional overlap. Upward pointing arrows indicate upregulated genes, downward pointing arrows indicate downregulated genes.

Mentions: Arabidopsis responses to treatments were highly dynamic (Figure 2). Since sampling was done 6 and 24 h after the removal of insects, the differences in expression between insects and control plants presumably represents a combination of induction and relaxation of gene expression responses. Across all treatments and tissues, overlap in genes differentially expressed at 6 and 24 h ranged from 3 to 15% and 1 to 8% for upregulated and downregulated genes, respectively (Figure 2A). The aphid M. persicae elicited far more differentially expressed genes at 6 h (n = 815, 45% up and 54% down) than at 24 h (n = 222, 74% up and 38% down) (Figure 3). In contrast, the aphid B. brassicae elicited fewer differentially expressed genes at 6 h (n = 188, 44% up and 56% down) than at 24 h (n = 249, 76% up and 23% down) Transcriptional responses to the two aphids across both times only shared a 4–8% overlap in differentially expressed genes. Both caterpillars elicited similar numbers of differentially expressed genes at 6 h and 24 h (Figures 2A, 3). However, the degree of overlap in these genes between the caterpillars differed with time, 24% up vs. 9% down at 6 h and 8% up vs. 4% down at 24 h for S. exigua and P. rapae, respectively. Feeding by S. exigua elicited the longest-lasting changes in gene expression and hence the most overlap in genes differentially expressed at both time points.


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)

Treatment comparisons with the number of genes differentially expressed in each treatment, the number of genes expressed in both treatments, and their proportional overlap. Upward pointing arrows indicate upregulated genes, downward pointing arrows indicate downregulated genes.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Treatment comparisons with the number of genes differentially expressed in each treatment, the number of genes expressed in both treatments, and their proportional overlap. Upward pointing arrows indicate upregulated genes, downward pointing arrows indicate downregulated genes.
Mentions: Arabidopsis responses to treatments were highly dynamic (Figure 2). Since sampling was done 6 and 24 h after the removal of insects, the differences in expression between insects and control plants presumably represents a combination of induction and relaxation of gene expression responses. Across all treatments and tissues, overlap in genes differentially expressed at 6 and 24 h ranged from 3 to 15% and 1 to 8% for upregulated and downregulated genes, respectively (Figure 2A). The aphid M. persicae elicited far more differentially expressed genes at 6 h (n = 815, 45% up and 54% down) than at 24 h (n = 222, 74% up and 38% down) (Figure 3). In contrast, the aphid B. brassicae elicited fewer differentially expressed genes at 6 h (n = 188, 44% up and 56% down) than at 24 h (n = 249, 76% up and 23% down) Transcriptional responses to the two aphids across both times only shared a 4–8% overlap in differentially expressed genes. Both caterpillars elicited similar numbers of differentially expressed genes at 6 h and 24 h (Figures 2A, 3). However, the degree of overlap in these genes between the caterpillars differed with time, 24% up vs. 9% down at 6 h and 8% up vs. 4% down at 24 h for S. exigua and P. rapae, respectively. Feeding by S. exigua elicited the longest-lasting changes in gene expression and hence the most overlap in genes differentially expressed at both time points.

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