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Comparative transcriptomics of Central Asian Vitis vinifera accessions reveals distinct defense strategies against powdery mildew.

Amrine KC, Blanco-Ulate B, Riaz S, Pap D, Jones L, Figueroa-Balderas R, Walker MA, Cantu D - Hortic Res (2015)

Bottom Line: To identify potential Ren1-dependent transcriptional responses and functions associated with the different levels of resistance, we sequenced and analyzed the transcriptomes of these Central Asian accessions at two time points of PM infection.Transcriptomes were compared to identify constitutive differences and PM-inducible responses that may underlie their disease resistant phenotype.This study provides a first exploration of the functions associated with varying levels of partial resistance to PM in V. vinifera accessions that can be exploited as sources of genetic resistance in grape breeding programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Viticulture and Enology, University of California , Davis, Davis, CA 95616, USA.

ABSTRACT
Grape powdery mildew (PM), caused by the biotrophic ascomycete Erysiphe necator, is a devastating fungal disease that affects most Vitis vinifera cultivars. We have previously identified a panel of V. vinifera accessions from Central Asia with partial resistance to PM that possess a Ren1-like local haplotype. In this study, we show that in addition to the typical Ren1-associated late post-penetration resistance, these accessions display a range of different levels of disease development suggesting that alternative alleles or additional genes contribute to determining the outcome of the interaction with the pathogen. To identify potential Ren1-dependent transcriptional responses and functions associated with the different levels of resistance, we sequenced and analyzed the transcriptomes of these Central Asian accessions at two time points of PM infection. Transcriptomes were compared to identify constitutive differences and PM-inducible responses that may underlie their disease resistant phenotype. Responses to E. necator in all resistant accessions were characterized by an early up-regulation of 13 genes, most encoding putative defense functions, and a late down-regulation of 32 genes, enriched in transcriptional regulators and protein kinases. Potential Ren1-dependent responses included a hotspot of co-regulated genes on chromosome 18. We also identified 81 genes whose expression levels and dynamics correlated with the phenotypic differences between the most resistant accessions 'Karadzhandahal', DVIT3351.27, and O34-16 and the other genotypes. This study provides a first exploration of the functions associated with varying levels of partial resistance to PM in V. vinifera accessions that can be exploited as sources of genetic resistance in grape breeding programs.

No MeSH data available.


Related in: MedlinePlus

Transcriptional responses to PM infection in the Central Asian accessions Barplots indicating the number of differentially regulated genes (P <0.05) at 1 (a) and 5 (b) dpi. Circos75 plots showing common differentially expressed genes between at least 6 resistant accessions at 1 (c) and 5 (d) dpi. Red and blue lines represent common up- and down-regulated genes, respectively. External bands correspond to each of the 19 chromosomes (+ Chr00) where the genes are located. A full list of genes represented by the connections in (c) and (d) are listed in Table 2. (e) Enriched GO terms (P <0.05) within the set of resistant-specific genes listed in Table 2. Darker colored circles represent terms with lower P values. Organization of sub-graphs is determined by REViGO web server.37 Boxes around terms group terms based on functional similarities, including (I) plant growth, (II) cell adhesion, (III) defense responses, (IV), cuticle formation, (V) phosphorylation, and (VI) cellular metabolism.
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fig4: Transcriptional responses to PM infection in the Central Asian accessions Barplots indicating the number of differentially regulated genes (P <0.05) at 1 (a) and 5 (b) dpi. Circos75 plots showing common differentially expressed genes between at least 6 resistant accessions at 1 (c) and 5 (d) dpi. Red and blue lines represent common up- and down-regulated genes, respectively. External bands correspond to each of the 19 chromosomes (+ Chr00) where the genes are located. A full list of genes represented by the connections in (c) and (d) are listed in Table 2. (e) Enriched GO terms (P <0.05) within the set of resistant-specific genes listed in Table 2. Darker colored circles represent terms with lower P values. Organization of sub-graphs is determined by REViGO web server.37 Boxes around terms group terms based on functional similarities, including (I) plant growth, (II) cell adhesion, (III) defense responses, (IV), cuticle formation, (V) phosphorylation, and (VI) cellular metabolism.

Mentions: To characterize transcriptional responses to E. necator, differentially expressed genes were identified by comparing mock-inoculated and PM-infected leaves from each accession. A union of 12 818 genes was differentially expressed in response to E. necator across all eight genotypes (P < 0.05). On average 776.1 ± 358.7 and 1541.8 ± 633.4 genes were significantly up-regulated in the seven resistant accessions at 1 and 5 dpi, respectively. E. necator also caused the down-regulation of 645 ± 344.7 genes at 1 dpi and 956.4 ± 535.2 at 5 dpi. A similar number of PM-responsive genes was detected in ‘Carignan’ at both time points. The largest number of PM-responsive genes at both time points was found in ‘Karadzhandal’, while ‘Late Vavilov’ showed the smallest number of differentially regulated genes in response to PM (Figure 4a and 4b).


Comparative transcriptomics of Central Asian Vitis vinifera accessions reveals distinct defense strategies against powdery mildew.

Amrine KC, Blanco-Ulate B, Riaz S, Pap D, Jones L, Figueroa-Balderas R, Walker MA, Cantu D - Hortic Res (2015)

Transcriptional responses to PM infection in the Central Asian accessions Barplots indicating the number of differentially regulated genes (P <0.05) at 1 (a) and 5 (b) dpi. Circos75 plots showing common differentially expressed genes between at least 6 resistant accessions at 1 (c) and 5 (d) dpi. Red and blue lines represent common up- and down-regulated genes, respectively. External bands correspond to each of the 19 chromosomes (+ Chr00) where the genes are located. A full list of genes represented by the connections in (c) and (d) are listed in Table 2. (e) Enriched GO terms (P <0.05) within the set of resistant-specific genes listed in Table 2. Darker colored circles represent terms with lower P values. Organization of sub-graphs is determined by REViGO web server.37 Boxes around terms group terms based on functional similarities, including (I) plant growth, (II) cell adhesion, (III) defense responses, (IV), cuticle formation, (V) phosphorylation, and (VI) cellular metabolism.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591678&req=5

fig4: Transcriptional responses to PM infection in the Central Asian accessions Barplots indicating the number of differentially regulated genes (P <0.05) at 1 (a) and 5 (b) dpi. Circos75 plots showing common differentially expressed genes between at least 6 resistant accessions at 1 (c) and 5 (d) dpi. Red and blue lines represent common up- and down-regulated genes, respectively. External bands correspond to each of the 19 chromosomes (+ Chr00) where the genes are located. A full list of genes represented by the connections in (c) and (d) are listed in Table 2. (e) Enriched GO terms (P <0.05) within the set of resistant-specific genes listed in Table 2. Darker colored circles represent terms with lower P values. Organization of sub-graphs is determined by REViGO web server.37 Boxes around terms group terms based on functional similarities, including (I) plant growth, (II) cell adhesion, (III) defense responses, (IV), cuticle formation, (V) phosphorylation, and (VI) cellular metabolism.
Mentions: To characterize transcriptional responses to E. necator, differentially expressed genes were identified by comparing mock-inoculated and PM-infected leaves from each accession. A union of 12 818 genes was differentially expressed in response to E. necator across all eight genotypes (P < 0.05). On average 776.1 ± 358.7 and 1541.8 ± 633.4 genes were significantly up-regulated in the seven resistant accessions at 1 and 5 dpi, respectively. E. necator also caused the down-regulation of 645 ± 344.7 genes at 1 dpi and 956.4 ± 535.2 at 5 dpi. A similar number of PM-responsive genes was detected in ‘Carignan’ at both time points. The largest number of PM-responsive genes at both time points was found in ‘Karadzhandal’, while ‘Late Vavilov’ showed the smallest number of differentially regulated genes in response to PM (Figure 4a and 4b).

Bottom Line: To identify potential Ren1-dependent transcriptional responses and functions associated with the different levels of resistance, we sequenced and analyzed the transcriptomes of these Central Asian accessions at two time points of PM infection.Transcriptomes were compared to identify constitutive differences and PM-inducible responses that may underlie their disease resistant phenotype.This study provides a first exploration of the functions associated with varying levels of partial resistance to PM in V. vinifera accessions that can be exploited as sources of genetic resistance in grape breeding programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Viticulture and Enology, University of California , Davis, Davis, CA 95616, USA.

ABSTRACT
Grape powdery mildew (PM), caused by the biotrophic ascomycete Erysiphe necator, is a devastating fungal disease that affects most Vitis vinifera cultivars. We have previously identified a panel of V. vinifera accessions from Central Asia with partial resistance to PM that possess a Ren1-like local haplotype. In this study, we show that in addition to the typical Ren1-associated late post-penetration resistance, these accessions display a range of different levels of disease development suggesting that alternative alleles or additional genes contribute to determining the outcome of the interaction with the pathogen. To identify potential Ren1-dependent transcriptional responses and functions associated with the different levels of resistance, we sequenced and analyzed the transcriptomes of these Central Asian accessions at two time points of PM infection. Transcriptomes were compared to identify constitutive differences and PM-inducible responses that may underlie their disease resistant phenotype. Responses to E. necator in all resistant accessions were characterized by an early up-regulation of 13 genes, most encoding putative defense functions, and a late down-regulation of 32 genes, enriched in transcriptional regulators and protein kinases. Potential Ren1-dependent responses included a hotspot of co-regulated genes on chromosome 18. We also identified 81 genes whose expression levels and dynamics correlated with the phenotypic differences between the most resistant accessions 'Karadzhandahal', DVIT3351.27, and O34-16 and the other genotypes. This study provides a first exploration of the functions associated with varying levels of partial resistance to PM in V. vinifera accessions that can be exploited as sources of genetic resistance in grape breeding programs.

No MeSH data available.


Related in: MedlinePlus