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Current understanding of grapevine defense mechanisms against the biotrophic fungus (Erysiphe necator), the causal agent of powdery mildew disease.

Qiu W, Feechan A, Dry I - Hortic Res (2015)

Bottom Line: The majority of grapevine cultivars used for wine, table grape, and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics.The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide.Finally, it addresses future research priorities which will be important in the rapid identification, evaluation, and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.

View Article: PubMed Central - PubMed

Affiliation: Center for Grapevine Biotechnology, W. H. Darr School of Agriculture, Missouri State University , Mountain Grove, MO 65711, USA.

ABSTRACT
The most economically important disease of cultivated grapevines worldwide is powdery mildew (PM) caused by the ascomycete fungus Erysiphe necator. The majority of grapevine cultivars used for wine, table grape, and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics. However, this species has little genetic resistance against E. necator meaning that grape production is highly dependent on the frequent use of fungicides. The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide. This review will outline the strategies being used to increase our understanding of the molecular basis of V. vinifera susceptibility to this fungal pathogen. It will summarize our current knowledge of different resistance loci/genes that have evolved in wild grapevine species to restrict PM infection and assess the potential application of these defense genes in the generation of PM-resistant grapevine germplasm. Finally, it addresses future research priorities which will be important in the rapid identification, evaluation, and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.

No MeSH data available.


Related in: MedlinePlus

Mechanisms of grapevine defense against the biotrophic fungal pathogen powdery mildew (E. necator). Grapevine powdery mildew spores were inoculated onto detached leaves of M. rotundifolia (A & B), V. vinifera cv. Cabernet Sauvignon (C) and a V. vinifera backcross progeny plant containing the powdery mildew resistance gene MrRUN1 (D). Leaf samples were collected after 2 days and fixed and stained with Coomassie brilliant blue to visualize fungal structures. Panels A and B represent the same field of view but are focused at different levels to show the germinated conidium (c) and appressoria (ap) on the surface of the leaf (panel A) and the globular papillae (arrows) beneath the appressoria (panel B) which are blocking penetration and haustoria formation. Panel C shows normal growth of E. necator hyphae (hy) across the leaf surface of a susceptible grapevine cultivar. Panel D shows the induction of MrRUN1-mediated programmed cell death in penetrated epidermal cells (arrows) which effectively halts further growth of this biotrophic pathogen.
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fig1: Mechanisms of grapevine defense against the biotrophic fungal pathogen powdery mildew (E. necator). Grapevine powdery mildew spores were inoculated onto detached leaves of M. rotundifolia (A & B), V. vinifera cv. Cabernet Sauvignon (C) and a V. vinifera backcross progeny plant containing the powdery mildew resistance gene MrRUN1 (D). Leaf samples were collected after 2 days and fixed and stained with Coomassie brilliant blue to visualize fungal structures. Panels A and B represent the same field of view but are focused at different levels to show the germinated conidium (c) and appressoria (ap) on the surface of the leaf (panel A) and the globular papillae (arrows) beneath the appressoria (panel B) which are blocking penetration and haustoria formation. Panel C shows normal growth of E. necator hyphae (hy) across the leaf surface of a susceptible grapevine cultivar. Panel D shows the induction of MrRUN1-mediated programmed cell death in penetrated epidermal cells (arrows) which effectively halts further growth of this biotrophic pathogen.

Mentions: There are two main strategies that plants use to restrict the invasion and growth of biotrophic fungal pathogens: penetration resistance and programmed cell death (PCD)-mediated resistance (Figure 1). Penetration resistance blocks the breach of the cell wall and membrane by the germinated spore and thus prevents the formation of the haustorium. The PCD-mediated resistance is exerted inside the penetrated epidermal cell and induces the death of invaded cell, thereby terminating the supply of nutrients required by the biotrophic fungus for further growth and development.


Current understanding of grapevine defense mechanisms against the biotrophic fungus (Erysiphe necator), the causal agent of powdery mildew disease.

Qiu W, Feechan A, Dry I - Hortic Res (2015)

Mechanisms of grapevine defense against the biotrophic fungal pathogen powdery mildew (E. necator). Grapevine powdery mildew spores were inoculated onto detached leaves of M. rotundifolia (A & B), V. vinifera cv. Cabernet Sauvignon (C) and a V. vinifera backcross progeny plant containing the powdery mildew resistance gene MrRUN1 (D). Leaf samples were collected after 2 days and fixed and stained with Coomassie brilliant blue to visualize fungal structures. Panels A and B represent the same field of view but are focused at different levels to show the germinated conidium (c) and appressoria (ap) on the surface of the leaf (panel A) and the globular papillae (arrows) beneath the appressoria (panel B) which are blocking penetration and haustoria formation. Panel C shows normal growth of E. necator hyphae (hy) across the leaf surface of a susceptible grapevine cultivar. Panel D shows the induction of MrRUN1-mediated programmed cell death in penetrated epidermal cells (arrows) which effectively halts further growth of this biotrophic pathogen.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595975&req=5

fig1: Mechanisms of grapevine defense against the biotrophic fungal pathogen powdery mildew (E. necator). Grapevine powdery mildew spores were inoculated onto detached leaves of M. rotundifolia (A & B), V. vinifera cv. Cabernet Sauvignon (C) and a V. vinifera backcross progeny plant containing the powdery mildew resistance gene MrRUN1 (D). Leaf samples were collected after 2 days and fixed and stained with Coomassie brilliant blue to visualize fungal structures. Panels A and B represent the same field of view but are focused at different levels to show the germinated conidium (c) and appressoria (ap) on the surface of the leaf (panel A) and the globular papillae (arrows) beneath the appressoria (panel B) which are blocking penetration and haustoria formation. Panel C shows normal growth of E. necator hyphae (hy) across the leaf surface of a susceptible grapevine cultivar. Panel D shows the induction of MrRUN1-mediated programmed cell death in penetrated epidermal cells (arrows) which effectively halts further growth of this biotrophic pathogen.
Mentions: There are two main strategies that plants use to restrict the invasion and growth of biotrophic fungal pathogens: penetration resistance and programmed cell death (PCD)-mediated resistance (Figure 1). Penetration resistance blocks the breach of the cell wall and membrane by the germinated spore and thus prevents the formation of the haustorium. The PCD-mediated resistance is exerted inside the penetrated epidermal cell and induces the death of invaded cell, thereby terminating the supply of nutrients required by the biotrophic fungus for further growth and development.

Bottom Line: The majority of grapevine cultivars used for wine, table grape, and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics.The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide.Finally, it addresses future research priorities which will be important in the rapid identification, evaluation, and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.

View Article: PubMed Central - PubMed

Affiliation: Center for Grapevine Biotechnology, W. H. Darr School of Agriculture, Missouri State University , Mountain Grove, MO 65711, USA.

ABSTRACT
The most economically important disease of cultivated grapevines worldwide is powdery mildew (PM) caused by the ascomycete fungus Erysiphe necator. The majority of grapevine cultivars used for wine, table grape, and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics. However, this species has little genetic resistance against E. necator meaning that grape production is highly dependent on the frequent use of fungicides. The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide. This review will outline the strategies being used to increase our understanding of the molecular basis of V. vinifera susceptibility to this fungal pathogen. It will summarize our current knowledge of different resistance loci/genes that have evolved in wild grapevine species to restrict PM infection and assess the potential application of these defense genes in the generation of PM-resistant grapevine germplasm. Finally, it addresses future research priorities which will be important in the rapid identification, evaluation, and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.

No MeSH data available.


Related in: MedlinePlus