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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

Number of the up-regulated and down-regulated DEGs for the time series of 6, 12, 24 and 48 h of Helicoverpa armigera feeding.The DEGs are those displaying a change of more than four-fold with a q-value of less than or equal to 0.05 for at least one time point.
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f3: Number of the up-regulated and down-regulated DEGs for the time series of 6, 12, 24 and 48 h of Helicoverpa armigera feeding.The DEGs are those displaying a change of more than four-fold with a q-value of less than or equal to 0.05 for at least one time point.

Mentions: Genes associated with a cut-off of q ≤ 0.05 and the value of log2/Ratio/ ≥2 considered to show significantly different expression. A total of 1,969 transcripts were differentially expressed at one or more time points (Supplementary Table S1). Among these 1,969 transcripts, 1,120 were significantly up-regulated, 846 were significantly down-regulated and only three were mixed (Supplementary Table S1). Many of these genes were differentially expressed at 6 h after the onset of CBW infestation, and the numbers of differentially expressed genes (DEGs) decreased thereafter. At all time points, more genes were up-regulated than down-regulated (Fig. 3). Gene functions were classified using Gene Ontology (GO) analysis. In total, twenty GO terms were attributed to one of the three GO ontologies (cellular component, molecular function and biological process) (Fig. 4). In the cellular components GO ontology, the top term was cell part. Meanwhile, most of the genes were classified into the function ontology of ion binding and transferase activity. The GO analysis also showed that both the biosynthetic process and nitrogen compound metabolic process GO categories were most abundant in the biological process ontology. Additionally, further analysis of GO clustering of commonly and exclusively expressed genes at four time points was carried out (Supplementary Figure S1). For GO clustering of catalytic activity, exclusively expressed genes at 48 h after CBW infestation accounted for the largest proportion followed by exclusively expressed genes at 6 h. Their corresponding percentages were higher in comparison to the percentage of commonly expressed genes at four time points, suggesting that most of plant responses to CBW were in common at 6 h and 48 h after infestation, although with an enhanced reaction at 48 h (Supplementary Figure S1A). Also, exclusively expressed genes at 48 h after CBW infestation have the largest proportion of DEGs involved in transcription factor activity, biological process, metabolic process and biosynthetic process (Supplementary Figure S1B and S1C). These GO analysis provided valuable clues to investigate the specific processes and molecular functions of transcriptome changes of cotton leaves in response to CBW infestation.


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)

Number of the up-regulated and down-regulated DEGs for the time series of 6, 12, 24 and 48 h of Helicoverpa armigera feeding.The DEGs are those displaying a change of more than four-fold with a q-value of less than or equal to 0.05 for at least one time point.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Number of the up-regulated and down-regulated DEGs for the time series of 6, 12, 24 and 48 h of Helicoverpa armigera feeding.The DEGs are those displaying a change of more than four-fold with a q-value of less than or equal to 0.05 for at least one time point.
Mentions: Genes associated with a cut-off of q ≤ 0.05 and the value of log2/Ratio/ ≥2 considered to show significantly different expression. A total of 1,969 transcripts were differentially expressed at one or more time points (Supplementary Table S1). Among these 1,969 transcripts, 1,120 were significantly up-regulated, 846 were significantly down-regulated and only three were mixed (Supplementary Table S1). Many of these genes were differentially expressed at 6 h after the onset of CBW infestation, and the numbers of differentially expressed genes (DEGs) decreased thereafter. At all time points, more genes were up-regulated than down-regulated (Fig. 3). Gene functions were classified using Gene Ontology (GO) analysis. In total, twenty GO terms were attributed to one of the three GO ontologies (cellular component, molecular function and biological process) (Fig. 4). In the cellular components GO ontology, the top term was cell part. Meanwhile, most of the genes were classified into the function ontology of ion binding and transferase activity. The GO analysis also showed that both the biosynthetic process and nitrogen compound metabolic process GO categories were most abundant in the biological process ontology. Additionally, further analysis of GO clustering of commonly and exclusively expressed genes at four time points was carried out (Supplementary Figure S1). For GO clustering of catalytic activity, exclusively expressed genes at 48 h after CBW infestation accounted for the largest proportion followed by exclusively expressed genes at 6 h. Their corresponding percentages were higher in comparison to the percentage of commonly expressed genes at four time points, suggesting that most of plant responses to CBW were in common at 6 h and 48 h after infestation, although with an enhanced reaction at 48 h (Supplementary Figure S1A). Also, exclusively expressed genes at 48 h after CBW infestation have the largest proportion of DEGs involved in transcription factor activity, biological process, metabolic process and biosynthetic process (Supplementary Figure S1B and S1C). These GO analysis provided valuable clues to investigate the specific processes and molecular functions of transcriptome changes of cotton leaves in response to CBW infestation.

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