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Dynamic transcriptome analysis and volatile profiling of Gossypium hirsutum in response to the cotton bollworm Helicoverpa armigera.

Huang XZ, Chen JY, Xiao HJ, Xiao YT, Wu J, Wu JX, Zhou JJ, Zhang YJ, Guo YY - Sci Rep (2015)

Bottom Line: Cluster analysis identified several distinct temporal patterns of transcriptome changes.Among CBW-induced genes, those associated with indirect defense and jasmonic acid pathway were clearly over-represented, indicating that these genes play important roles in CBW-induced defenses.The present results increase our knowledge about insect herbivory-induced metabolic and biochemical processes in plants, which may help improve future studies on genes governing processes.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Plant Protection, Northwest A &F University, Yangling, Shaanxi 712100, China [2] State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

ABSTRACT
In response to insect herbivory, plants emit elevated levels of volatile organic compounds for direct and indirect resistance. However, little is known about the molecular and genomic basis of defense response that insect herbivory trigger in cotton plants and how defense mechanisms are orchestrated in the context of other biological processes. Here we monitored the transcriptome changes and volatile characteristics of cotton plants in response to cotton bollworm (CBW; Helicoverpa armigera) larvae infestation. Analysis of samples revealed that 1,969 transcripts were differentially expressed (log2/Ratio/ ≥ 2; q ≤ 0.05) after CBW infestation. Cluster analysis identified several distinct temporal patterns of transcriptome changes. Among CBW-induced genes, those associated with indirect defense and jasmonic acid pathway were clearly over-represented, indicating that these genes play important roles in CBW-induced defenses. The gas chromatography-mass spectrometry (GC-MS) analyses revealed that CBW infestation could induce cotton plants to release volatile compounds comprised lipoxygenase-derived green leaf volatiles and a number of terpenoid volatiles. Responding to CBW larvae infestation, cotton plants undergo drastic reprogramming of the transcriptome and the volatile profile. The present results increase our knowledge about insect herbivory-induced metabolic and biochemical processes in plants, which may help improve future studies on genes governing processes.

No MeSH data available.


Related in: MedlinePlus

Secondary metabolite pathways expressed in Gossypium hirsutum after feeding by the cotton bollworm Helicoverpa armigera.The map was generated with iPath ( http://pathways.embl.de), a web-based tool for the visualization of metabolic pathways.
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f7: Secondary metabolite pathways expressed in Gossypium hirsutum after feeding by the cotton bollworm Helicoverpa armigera.The map was generated with iPath ( http://pathways.embl.de), a web-based tool for the visualization of metabolic pathways.

Mentions: We further analyzed the expression patterns of genes of secondary metabolite pathways that are known to be affected by herbivory, specifically phenylpropanoid, flavonoid and terpenoid metabolism (Fig. 7 and Supplementary Table S8 and S9). Many transcripts from these pathways were differentially expressed upon CBW feeding. The largest subgroup was phenylpropanoid biosynthesis (16 up- and 12 down-regulated genes), followed by flavonoid biosynthesis genes, most of which (21 of 23) were down-regulated. For the phenylpropanoid pathway, the first committed step is catalyzed by L-phenylalanine ammonia lyase (PAL), a well-known and widely distributed enzyme. Microarray analysis showed that one PAL was up-regulated within 6 h after the onset of CBW feeding, and three other PALs displayed repressed expression at the 48 h time point. CBW feeding induced two genes that have been functionally characterized as encoding enzymes of the flavonoid pathway, but many of the genes in this pathway were represented. To elucidate the molecular basis for the biosynthesis of volatiles involved in indirect defenses of cotton to CBW, we mainly addressed terpenoid metabolism (Fig. 8). Three genes encoding the crucial enzyme of the non-mevalonate pathway, 1-deoxy-D-xylulose 5-phosphate synthase were modestly down-regulated by CBW feeding. In contrast, two hydroxymethylglutaryl-CoA reductases of the mevalonate pathway were up-regulated. Consistently, a geranyl diphosphate synthase was down-regulated, and a farnesyl diphosphate synthase was up-regulated. In addition, two monoterpene synthases, including a previously characterized pinene synthase, and four cadinene synthases, a sesquiterpene synthases and the catalyst for cotton phytoalexin biosynthesis, were up-regulated.


Dynamic transcriptome analysis and volatile profiling of Gossypium hirsutum in response to the cotton bollworm Helicoverpa armigera.

Huang XZ, Chen JY, Xiao HJ, Xiao YT, Wu J, Wu JX, Zhou JJ, Zhang YJ, Guo YY - Sci Rep (2015)

Secondary metabolite pathways expressed in Gossypium hirsutum after feeding by the cotton bollworm Helicoverpa armigera.The map was generated with iPath ( http://pathways.embl.de), a web-based tool for the visualization of metabolic pathways.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493570&req=5

f7: Secondary metabolite pathways expressed in Gossypium hirsutum after feeding by the cotton bollworm Helicoverpa armigera.The map was generated with iPath ( http://pathways.embl.de), a web-based tool for the visualization of metabolic pathways.
Mentions: We further analyzed the expression patterns of genes of secondary metabolite pathways that are known to be affected by herbivory, specifically phenylpropanoid, flavonoid and terpenoid metabolism (Fig. 7 and Supplementary Table S8 and S9). Many transcripts from these pathways were differentially expressed upon CBW feeding. The largest subgroup was phenylpropanoid biosynthesis (16 up- and 12 down-regulated genes), followed by flavonoid biosynthesis genes, most of which (21 of 23) were down-regulated. For the phenylpropanoid pathway, the first committed step is catalyzed by L-phenylalanine ammonia lyase (PAL), a well-known and widely distributed enzyme. Microarray analysis showed that one PAL was up-regulated within 6 h after the onset of CBW feeding, and three other PALs displayed repressed expression at the 48 h time point. CBW feeding induced two genes that have been functionally characterized as encoding enzymes of the flavonoid pathway, but many of the genes in this pathway were represented. To elucidate the molecular basis for the biosynthesis of volatiles involved in indirect defenses of cotton to CBW, we mainly addressed terpenoid metabolism (Fig. 8). Three genes encoding the crucial enzyme of the non-mevalonate pathway, 1-deoxy-D-xylulose 5-phosphate synthase were modestly down-regulated by CBW feeding. In contrast, two hydroxymethylglutaryl-CoA reductases of the mevalonate pathway were up-regulated. Consistently, a geranyl diphosphate synthase was down-regulated, and a farnesyl diphosphate synthase was up-regulated. In addition, two monoterpene synthases, including a previously characterized pinene synthase, and four cadinene synthases, a sesquiterpene synthases and the catalyst for cotton phytoalexin biosynthesis, were up-regulated.

Bottom Line: Cluster analysis identified several distinct temporal patterns of transcriptome changes.Among CBW-induced genes, those associated with indirect defense and jasmonic acid pathway were clearly over-represented, indicating that these genes play important roles in CBW-induced defenses.The present results increase our knowledge about insect herbivory-induced metabolic and biochemical processes in plants, which may help improve future studies on genes governing processes.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Plant Protection, Northwest A &F University, Yangling, Shaanxi 712100, China [2] State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

ABSTRACT
In response to insect herbivory, plants emit elevated levels of volatile organic compounds for direct and indirect resistance. However, little is known about the molecular and genomic basis of defense response that insect herbivory trigger in cotton plants and how defense mechanisms are orchestrated in the context of other biological processes. Here we monitored the transcriptome changes and volatile characteristics of cotton plants in response to cotton bollworm (CBW; Helicoverpa armigera) larvae infestation. Analysis of samples revealed that 1,969 transcripts were differentially expressed (log2/Ratio/ ≥ 2; q ≤ 0.05) after CBW infestation. Cluster analysis identified several distinct temporal patterns of transcriptome changes. Among CBW-induced genes, those associated with indirect defense and jasmonic acid pathway were clearly over-represented, indicating that these genes play important roles in CBW-induced defenses. The gas chromatography-mass spectrometry (GC-MS) analyses revealed that CBW infestation could induce cotton plants to release volatile compounds comprised lipoxygenase-derived green leaf volatiles and a number of terpenoid volatiles. Responding to CBW larvae infestation, cotton plants undergo drastic reprogramming of the transcriptome and the volatile profile. The present results increase our knowledge about insect herbivory-induced metabolic and biochemical processes in plants, which may help improve future studies on genes governing processes.

No MeSH data available.


Related in: MedlinePlus