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Characterization and expression profiling of glutathione S-transferases in the diamondback moth, Plutella xylostella (L.).

You Y, Xie M, Ren N, Cheng X, Li J, Ma X, Zou M, Vasseur L, Gurr GM, You M - BMC Genomics (2015)

Bottom Line: Delta, Epsilon and Omega GSTs were numerically superior with 5 genes for each of the subclasses.The resulting phylogenetic tree showed that the P. xylostella GSTs were all clustered into Lepidoptera-specific branches.The diversified features and expression patterns of the GSTs are inferred to be associated with the capacity of this species to develop resistance to a wide range of pesticides and biological toxins.

View Article: PubMed Central - PubMed

Affiliation: Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. fzyouyc@gmail.com.

ABSTRACT

Background: Glutathione S-transferases (GSTs) are multifunctional detoxification enzymes that play important roles in insects. The completion of several insect genome projects has enabled the identification and characterization of GST genes over recent years. This study presents a genome-wide investigation of the diamondback moth (DBM), Plutella xylostella, a species in which the GSTs are of special importance because this pest is highly resistant to many insecticides.

Results: A total of 22 putative cytosolic GSTs were identified from a published P. xylostella genome and grouped into 6 subclasses (with two unclassified). Delta, Epsilon and Omega GSTs were numerically superior with 5 genes for each of the subclasses. The resulting phylogenetic tree showed that the P. xylostella GSTs were all clustered into Lepidoptera-specific branches. Intron sites and phases as well as GSH binding sites were strongly conserved within each of the subclasses in the GSTs of P. xylostella. Transcriptome-, RNA-seq- and qRT-PCR-based analyses showed that the GST genes were developmental stage- and strain-specifically expressed. Most of the highly expressed genes in insecticide resistant strains were also predominantly expressed in the Malpighian tubules, midgut or epidermis.

Conclusions: To date, this is the most comprehensive study on genome-wide identification, characterization and expression profiling of the GST family in P. xylostella. The diversified features and expression patterns of the GSTs are inferred to be associated with the capacity of this species to develop resistance to a wide range of pesticides and biological toxins. Our findings provide a base for functional research on specific GST genes, a better understanding of the evolution of insecticide resistance, and strategies for more sustainable management of the pest.

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Expression profiling of the PxGSTs at different developmental stages based on RPKM value. 1st (L): first instar larva; 2nd (L): second instar larva; 3rd (L): third instar larva; 4th (L): fourth instar larva; F: female; M: male; Gray denoted missing values. The data were obtained from our unpublished RNA-seq data. The RPKM values are presented in Additional file 7: Table S3. The data have been uploaded to the P. xylostella genomic database (DBM-DB: http://iae.fafu.edu.cn/DBM/family/PxGSTs.php).
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Fig4: Expression profiling of the PxGSTs at different developmental stages based on RPKM value. 1st (L): first instar larva; 2nd (L): second instar larva; 3rd (L): third instar larva; 4th (L): fourth instar larva; F: female; M: male; Gray denoted missing values. The data were obtained from our unpublished RNA-seq data. The RPKM values are presented in Additional file 7: Table S3. The data have been uploaded to the P. xylostella genomic database (DBM-DB: http://iae.fafu.edu.cn/DBM/family/PxGSTs.php).

Mentions: Using our unpublished P. xylostella RNA-seq data, expression patterns of the PxGSTs at different developmental stages of the susceptible strain were characterized (Figure 4, Additional file 7: Table S3). The results showed that all 22 PxGSTs could be expressed at different developmental stages, and exhibited gene-differential and stage-specific patterns. Sixteen genes were found to be consistently expressed throughout different stages, two of which (PxGSTd2 and PxGSTs2, Figure 4, I) tended to be expressed with high levels, four (PxGSTd3, PxGSTu1, PxGSTo2, and PxGSTo3) with moderate levels (Figure 4, III) and ten with low levels (Figure 4, IV). Those highly and moderately expressed genes may function as housekeeping genes with potential roles of protecting cells against endogenous oxidative stress or xenobiotics [28]. Four insect-specific PxGSTs (Figure 4, II) were predominantly and highly expressed at in larval (the main feeding stage), indicating that these genes might play important roles in metabolizing plant secondary metabolites [45,46].Figure 4


Characterization and expression profiling of glutathione S-transferases in the diamondback moth, Plutella xylostella (L.).

You Y, Xie M, Ren N, Cheng X, Li J, Ma X, Zou M, Vasseur L, Gurr GM, You M - BMC Genomics (2015)

Expression profiling of the PxGSTs at different developmental stages based on RPKM value. 1st (L): first instar larva; 2nd (L): second instar larva; 3rd (L): third instar larva; 4th (L): fourth instar larva; F: female; M: male; Gray denoted missing values. The data were obtained from our unpublished RNA-seq data. The RPKM values are presented in Additional file 7: Table S3. The data have been uploaded to the P. xylostella genomic database (DBM-DB: http://iae.fafu.edu.cn/DBM/family/PxGSTs.php).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC4358871&req=5

Fig4: Expression profiling of the PxGSTs at different developmental stages based on RPKM value. 1st (L): first instar larva; 2nd (L): second instar larva; 3rd (L): third instar larva; 4th (L): fourth instar larva; F: female; M: male; Gray denoted missing values. The data were obtained from our unpublished RNA-seq data. The RPKM values are presented in Additional file 7: Table S3. The data have been uploaded to the P. xylostella genomic database (DBM-DB: http://iae.fafu.edu.cn/DBM/family/PxGSTs.php).
Mentions: Using our unpublished P. xylostella RNA-seq data, expression patterns of the PxGSTs at different developmental stages of the susceptible strain were characterized (Figure 4, Additional file 7: Table S3). The results showed that all 22 PxGSTs could be expressed at different developmental stages, and exhibited gene-differential and stage-specific patterns. Sixteen genes were found to be consistently expressed throughout different stages, two of which (PxGSTd2 and PxGSTs2, Figure 4, I) tended to be expressed with high levels, four (PxGSTd3, PxGSTu1, PxGSTo2, and PxGSTo3) with moderate levels (Figure 4, III) and ten with low levels (Figure 4, IV). Those highly and moderately expressed genes may function as housekeeping genes with potential roles of protecting cells against endogenous oxidative stress or xenobiotics [28]. Four insect-specific PxGSTs (Figure 4, II) were predominantly and highly expressed at in larval (the main feeding stage), indicating that these genes might play important roles in metabolizing plant secondary metabolites [45,46].Figure 4

Bottom Line: Delta, Epsilon and Omega GSTs were numerically superior with 5 genes for each of the subclasses.The resulting phylogenetic tree showed that the P. xylostella GSTs were all clustered into Lepidoptera-specific branches.The diversified features and expression patterns of the GSTs are inferred to be associated with the capacity of this species to develop resistance to a wide range of pesticides and biological toxins.

View Article: PubMed Central - PubMed

Affiliation: Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. fzyouyc@gmail.com.

ABSTRACT

Background: Glutathione S-transferases (GSTs) are multifunctional detoxification enzymes that play important roles in insects. The completion of several insect genome projects has enabled the identification and characterization of GST genes over recent years. This study presents a genome-wide investigation of the diamondback moth (DBM), Plutella xylostella, a species in which the GSTs are of special importance because this pest is highly resistant to many insecticides.

Results: A total of 22 putative cytosolic GSTs were identified from a published P. xylostella genome and grouped into 6 subclasses (with two unclassified). Delta, Epsilon and Omega GSTs were numerically superior with 5 genes for each of the subclasses. The resulting phylogenetic tree showed that the P. xylostella GSTs were all clustered into Lepidoptera-specific branches. Intron sites and phases as well as GSH binding sites were strongly conserved within each of the subclasses in the GSTs of P. xylostella. Transcriptome-, RNA-seq- and qRT-PCR-based analyses showed that the GST genes were developmental stage- and strain-specifically expressed. Most of the highly expressed genes in insecticide resistant strains were also predominantly expressed in the Malpighian tubules, midgut or epidermis.

Conclusions: To date, this is the most comprehensive study on genome-wide identification, characterization and expression profiling of the GST family in P. xylostella. The diversified features and expression patterns of the GSTs are inferred to be associated with the capacity of this species to develop resistance to a wide range of pesticides and biological toxins. Our findings provide a base for functional research on specific GST genes, a better understanding of the evolution of insecticide resistance, and strategies for more sustainable management of the pest.

Show MeSH
Related in: MedlinePlus