Verticillium dahliae effector VDAL protects MYB6 from degradation by interacting with PUB25/26 E3 ligases for enhancing Verticillium wilt resistance in Arabidopsis

Verticillium wilt is a severe plant disease, increasing the plant resistance to this disease is a critical challenge worldwide. Here, we report that the Verticillium dahliae (V. dahliae)-secreted Aspf2-like protein VDAL causes leaf wilting when applied to cotton leaves in vitro, but enhances the resistance to V. dahliae when overexpressed in Arabidopsis or cotton. VDAL interacts with Arabidopsis E3 ligases PUB25 and PUB26 (PUBs) and is ubiquitinated by PUBs in vitro. However, VDAL is not degraded by PUBs in planta. Besides, the pub25 pub26 shows higher resistance to V. dahliae than the wild type. PUBs interact with the transcription factor MYB6 in a yeast two-hybrid screen. MYB6 promotes plant resistance to Verticillium wilt while PUBs ubiquitinate MYB6 and mediate its degradation. VDAL competes with MYB6 for binding to PUBs, and the role of VDAL in increasing wilt disease depends on MYB6. These results suggest that plants evolute a strategy to utilize the invaded effector protein VDAL to resist the V. dahliae infection without causing a hypersensitive response. This study provides the molecular mechanism for plants increasing disease resistance when overexpressing some effector proteins, and may promote searching for more genes from pathogenic fungi or bacteria to engineer plant disease resistance.

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Verticillium dahliae effector VDAL protects MYB6 from degradation by interacting with PUB25 and PUB26 E3 ligases to enhance Verticillium wilt resistance

The Plant Cell ◽

10.1093/plcell/koab221 ◽

2021 ◽

Author(s):

Aifang Ma ◽

Dingpeng Zhang ◽

Guangxing Wang ◽

Kai Wang ◽

Zhen Li ◽

...

Keyword(s):

Disease Resistance ◽

Verticillium Wilt ◽

Verticillium Dahliae ◽

Plant Resistance ◽

Plant Disease Resistance ◽

Plant Disease ◽

Wilt Resistance ◽

E3 Ligases ◽

Verticillium Wilt Resistance

Abstract Verticillium wilt is a severe plant disease that causes massive losses in multiple crops. Increasing the plant resistance to Verticillium wilt is a critical challenge worldwide. Here, we report that the hemibiotrophic Verticillium dahliae-secreted Asp f2-like protein VDAL causes leaf wilting when applied to cotton leaves in vitro but enhances the resistance to V. dahliae when overexpressed in Arabidopsis or cotton without affecting the plant growth and development. VDAL protein interacts with Arabidopsis E3 ligases plant U-box 25 (PUB25) and PUB26 and is ubiquitinated by PUBs in vitro. However, VDAL is not degraded by PUB25 or PUB26 in planta. Besides, the pub25 pub26 double mutant shows higher resistance to V. dahliae than the wild-type. PUBs interact with the transcription factor MYB6 in a yeast two-hybrid screen. MYB6 promotes plant resistance to Verticillium wilt while PUBs ubiquitinate MYB6 and mediate its degradation. VDAL competes with MYB6 for binding to PUBs, and the role of VDAL in increasing Verticillium wilt resistance depends on MYB6. Taken together, these results suggest that plants evolute a strategy to utilize the invaded effector protein VDAL to resist the V. dahliae infection without causing a hypersensitive response (HR); alternatively, hemibiotrophic pathogens may use some effectors to keep plant cells alive during its infection in order to take nutrients from host cells. This study provides the molecular mechanism for plants increasing disease resistance when overexpressing some effector proteins without inducing HR, and may promote searching for more genes from pathogenic fungi or bacteria to engineer plant disease resistance.

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Cross-reactivity of a rice NLR immune receptor to distinct effectors from the blast pathogen leads to partial disease resistance

10.1101/530675 ◽

2019 ◽

Cited By ~ 2

Author(s):

Freya A. Varden ◽

Hiromasa Saitoh ◽

Kae Yoshino ◽

Marina Franceschetti ◽

Sophien Kamoun ◽

...

Keyword(s):

Immune Response ◽

Disease Resistance ◽

Effector Proteins ◽

In Planta ◽

Immune Receptor ◽

Immune Receptors ◽

Binding Interface ◽

Pathogen Effector ◽

Integrated Domains

ABSTRACTUnconventional integrated domains in plant intracellular immune receptors (NLRs) can directly bind translocated pathogen effector proteins to initiate an immune response. The rice immune receptor pairs Pik-1/Pik-2 and RGA5/RGA4 both use integrated heavy metal-associated (HMA) domains to bind the Magnaporthe oryzae effectors AVR-Pik and AVR-Pia, respectively. These effectors both belong to the MAX effector family and share a core structural fold, despite being divergent in sequence. How integrated domains maintain specificity of recognition, even for structurally similar effectors, has implications for understanding plant immune receptor evolution and function. Here we show that the rice NLR pair Pikp-1/Pikp-2 triggers an immune response leading to partial disease resistance towards the “mismatched” effector AVR-Pia in planta, and that the Pikp-HMA domain binds AVR-Pia in vitro. The HMA domain from another Pik-1 allele, Pikm, is unable to bind AVR-Pia, and does not trigger a response in plants. The crystal structure of Pikp-HMA bound to AVR-Pia reveals a different binding interface compared to AVR-Pik effectors, suggesting plasticity in integrated domain/effector interactions. This work shows how a single NLR can bait multiple pathogen effectors via an integrated domain, and may enable engineering immune receptors with extended disease resistance profiles.

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Biosynthesis of cabbage phytoalexins from indole glucosinolate

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1615625114 ◽

2017 ◽

Vol 114 (8) ◽

pp. 1910-1915 ◽

Cited By ~ 35

Author(s):

Andrew P. Klein ◽

Elizabeth S. Sattely

Keyword(s):

Disease Resistance ◽

Plant Disease Resistance ◽

Plant Disease ◽

Biochemical Characterization ◽

Edible Plant ◽

Crop Species ◽

Important Pathway ◽

Indole Glucosinolate ◽

The Impact

Brassicacrop species are prolific producers of indole–sulfur phytoalexins that are thought to have an important role in plant disease resistance. These molecules are conspicuously absent in the model plantArabidopsis thaliana, and little is known about the enzymatic steps that assemble the key precursor brassinin. Here, we report the minimum set of biosynthetic genes required to generate cruciferous phytoalexins starting from the well-studied glucosinolate pathway. In vitro biochemical characterization revealed an additional role for the previously described carbon–sulfur lyase SUR1 in processing cysteine–isothiocyanate conjugates, as well as theS-methyltransferase DTCMT that methylates the resulting dithiocarbamate, together completing a pathway to brassinin. Additionally, the β-glucosidase BABG that is present inBrassica rapabut absent inArabidopsiswas shown to act as a myrosinase and may be a determinant of plants that synthesize phytoalexins from indole glucosinolate. Transient expression of the entire pathway inNicotiana benthamianayields brassinin, demonstrating that the biosynthesis of indole–sulfur phytoalexins can be engineered into noncruciferous plants. The identification of these biosynthetic enzymes and the heterologous reconstitution of the indole–sulfur phytoalexin pathway sheds light on an important pathway in an edible plant and opens the door to using metabolic engineering to systematically quantify the impact of cruciferous phytoalexins on plant disease resistance and human health.

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Antifungal Activity of Propyl-Propane-Thiosulfinate (PTS) and Propyl-Propane-Thiosulfonate (PTSO) from Allium cepa against Verticillium dahliae: In Vitro and in Planta Assays

Journal of Fungi ◽

10.3390/jof7090736 ◽

2021 ◽

Vol 7 (9) ◽

pp. 736

Author(s):

Ana Falcón-Piñeiro ◽

Efrén Remesal ◽

Miguel Noguera ◽

Juan José Ariza ◽

Enrique Guillamón ◽

...

Keyword(s):

Antifungal Activity ◽

Allium Cepa ◽

Verticillium Wilt ◽

Verticillium Dahliae ◽

Mycelial Growth ◽

Diffusion Method ◽

Organosulfur Compounds ◽

In Planta ◽

Effective Measure

Verticillium wilt, caused by Verticillium dahliae, is the most devastating soil-borne fungal disease of olive trees worldwide. Currently, there is no effective measure available to control the pathogen in diseased plants in open field conditions. Searching more effective and sustainable solutions are a priority for the olive sector. The existing alternatives for disease control include the use of biological control microorganisms and compounds of natural origin from plants, such as Alliaceae. Propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO) are two organosulfur compounds derived from Allium cepa with a widely documented antimicrobial activity. The aim of this study was to evaluate the antifungal activity of PTS and PTSO against the defoliating and non-defoliating V. dahliae pathotypes. Firstly, several in vitro tests were performed (Minimum Antifungal Concentration, susceptibility studies according to the Kirby–Bauer disk-diffusion method, antifungal activity through aerial diffusion and effect on mycelial growth). The ability of both compounds to sanitize soil was evaluated using a sterile substrate inoculated with V. dahliae. Finally, challenges in growth chambers were carried out. PTS and PTSO generated growth inhibition zones in agar diffusion and the gas phase, and the mycelial growth of all the V. dahliae strains was significantly altered. The V. dahliae population in soil was considerably reduced after the sanitization. Finally, in planta assays demonstrated the ability of these compounds to reduce disease related parameters and their contribution to control the phytopathogen. In conclusion, the results showed that the PTS and PTSO from Allium cepa display in vitro and in vivo antifungal activity against V. dahliae and suggested that both compounds could be used as natural and environmentally friendly tools for Verticillium wilt management.

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