Glucuronan and oligoglucuronans isolated from green algae activate natural defense responses in apple fruit and reduce postharvest blue and gray mold decay

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, and ornamentals. Fludioxonil-sensitive B. cinerea isolates were collected in 2011 and 2013 from commercial storage in Pennsylvania. Eight isolates had values for effective concentrations for inhibiting 50% of mycelial growth of 0.0004 to 0.0038 μg/ml for fludioxonil and were dual resistant to pyrimethanil and thiabendazole. Resistance was generated in vitro, following exposure to a sublethal dose of fludioxonil, in seven of eight dual-resistant B. cinerea isolates. Three vigorously growing B. cinerea isolates with multiresistance to postharvest fungicides were further characterized and found to be osmosensitive and retained resistance in the absence of selection pressure. A representative multiresistant B. cinerea strain caused decay on apple fruit treated with postharvest fungicides, which confirmed the in vitro results. The R632I mutation in the Mrr1 gene, associated with fludioxonil resistance in B. cinerea, was not detected in multipostharvest fungicide-resistant B. cinerea isolates, suggesting that the fungus may be using additional mechanisms to mediate resistance. Results from this study show for the first time that B. cinerea with dual resistance to pyrimethanil and thiabendazole can also rapidly develop resistance to fludioxonil, which may pose control challenges in the packinghouse environment and during long-term storage.

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Priming of Defense Systems and Upregulation of MYC2 and JAZ1 Genes after Botrytis cinerea Inoculation in Methyl Jasmonate-Treated Strawberry Fruits

Plants ◽

10.3390/plants9040447 ◽

2020 ◽

Vol 9 (4) ◽

pp. 447 ◽

Cited By ~ 1

Author(s):

Felipe Valenzuela-Riffo ◽

Paz E. Zúñiga ◽

Luis Morales-Quintana ◽

Mauricio Lolas ◽

Marcela Cáceres ◽

...

Keyword(s):

Methyl Jasmonate ◽

Botrytis Cinerea ◽

Defense Responses ◽

Gray Mold ◽

The Past ◽

Defense Systems ◽

Meja Treatment ◽

Fruit Development And Ripening ◽

Genes Encoding ◽

And Control

Several attempts have been made to study the effects of methyl jasmonate (MeJA) on plants in the past years. However, the comparative effects of the number and phenological time of MeJA applications on the activation of defense systems is currently unknown in strawberries. In the present research, we performed three field treatments during strawberry (Fragaria × ananassa ‘Camarosa’) fruit development and ripening which consisted of differential MeJA applications at flowering (M3), and the large green (M2 and M3) and red ripe (M1, M2, and M3) fruit stages. We also checked changes in gene expression related to plant defense against Botrytis cinerea inoculation post-harvest. In M3 treatment, we observed an upregulation of the anthocyanin and lignin contents and the defense-related genes, encoding for chitinases, β-1,3-glucanases and polygalacturonase-inhibiting proteins, after harvest (0 hpi), along with the jasmonate signaling-related genes FaMYC2 and FaJAZ1 at 48 h after B. cinerea inoculation (48 hpi) during postharvest storage. Although we did not find differences in gray mold incidence between the MeJA treatments and control, these results suggest that preharvest MeJA treatment from the flowering stage onwards (M3) primes defense responses mediated by the upregulation of different defense-related genes and retains the upregulation of MYC2 and JAZ1 at 48 hpi.

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Mycoactive Acetate Esters from Apple Fruit Stimulate Adhesion and Germination of Conidia of the Gray Mold Fungus

Journal of Agricultural and Food Chemistry ◽

10.1021/jf011390r ◽

2002 ◽

Vol 50 (11) ◽

pp. 3137-3142 ◽

Cited By ~ 7

Author(s):

A. B. Filonow

Keyword(s):

Gray Mold ◽

Apple Fruit ◽

Acetate Esters ◽

Mold Fungus

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Ultrastructural and Cytochemical Aspects of the Biological Control of Botrytis cinerea by Candida saitoana in Apple Fruit

Phytopathology ◽

10.1094/phyto.1998.88.4.282 ◽

1998 ◽

Vol 88 (4) ◽

pp. 282-291 ◽

Cited By ~ 111

Author(s):

Ahmed El-Ghaouth ◽

Charles L. Wilson ◽

Michael Wisniewski

Keyword(s):

Host Cell ◽

Botrytis Cinerea ◽

Cell Walls ◽

Close Contact ◽

Defense Responses ◽

Apple Fruit ◽

Penicillium Expansum ◽

Fungal Colonization ◽

Biocontrol Activity ◽

Apple Tissue

Biocontrol activity of Candida saitoana and its interaction with Botrytis cinerea in apple wounds were investigated. When cultured together, yeast attached to Botrytis sp. hyphal walls. In wounded apple tissue, C. saitoana restricted the proliferation of B. cinerea, multiplied, and suppressed disease caused by either B. cinerea or Penicillium expansum. In inoculated apple tissue without the yeast, fungal colonization caused an extensive degradation of host walls and altered cellulose labeling patterns. Hyphae in close proximity to the antagonistic yeast exhibited severe cytological injury, such as cell wall swelling and protoplasm degeneration. Colonization of the wound site by C. saitoana did not cause degradation of host cell walls. Host cell walls in close contact with C. saitoana cells and B. cinerea hyphae were well preserved and displayed an intense and regular cellulose labeling pattern. In addition to restricting fungal colonization, C. saitoana induced the formation of structural defense responses in apple tissue. The ability of C. saitoana to prevent the necrotrophic growth of the pathogen and stimulate structural defense responses may be the basis of its biocontrol activity.

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Exogenous bamboo pyroligneous acid improves antioxidant capacity and primes defense responses of harvested apple fruit

LWT ◽

10.1016/j.lwt.2020.110191 ◽

2020 ◽

Vol 134 ◽

pp. 110191

Author(s):

Xiaoyun Liu ◽

Jiangkuo Li ◽

Xiaomin Cui ◽

Dongchao Ji ◽

Yong Xu ◽

...

Keyword(s):

Antioxidant Capacity ◽

Defense Responses ◽

Apple Fruit ◽

Pyroligneous Acid

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Expression of Putative Defense Responses in Cannabis Primed by Pseudomonas and/or Bacillus Strains and Infected by Botrytis cinerea

Frontiers in Plant Science ◽

10.3389/fpls.2020.572112 ◽

2020 ◽

Vol 11 ◽

Author(s):

Carole Balthazar ◽

Gabrielle Cantin ◽

Amy Novinscak ◽

David L. Joly ◽

Martin Filion

Keyword(s):

Botrytis Cinerea ◽

Cannabis Sativa ◽

Molecular Level ◽

Quantitative Polymerase Chain Reaction ◽

Defense Responses ◽

Gray Mold ◽

Control Measures ◽

Effective Control ◽

Defense Genes ◽

Polymerase Chain

Cannabis (Cannabis sativa L.) offers many industrial, agricultural, and medicinal applications, but is commonly threatened by the gray mold disease caused by the fungus Botrytis cinerea. With few effective control measures currently available, the use of beneficial rhizobacteria represents a promising biocontrol avenue for cannabis. To counter disease development, plants rely on a complex network of inducible defense pathways, allowing them to respond locally and systemically to pathogens attacks. In this study, we present the first attempt to control gray mold in cannabis using beneficial rhizobacteria, and the first investigation of cannabis defense responses at the molecular level. Four promising Pseudomonas (LBUM223 and WCS417r) and Bacillus strains (LBUM279 and LBUM979) were applied as single or combined root treatments to cannabis seedlings, which were subsequently infected by B. cinerea. Symptoms were recorded and the expression of eight putative defense genes was monitored in leaves by reverse transcription quantitative polymerase chain reaction. The rhizobacteria did not significantly control gray mold and all infected leaves were necrotic after a week, regardless of the treatment. Similarly, no systemic activation of putative cannabis defense genes was reported, neither triggered by the pathogen nor by the rhizobacteria. However, this work identified five putative defense genes (ERF1, HEL, PAL, PR1, and PR2) that were strongly and sustainably induced locally at B. cinerea’s infection sites, as well as two stably expressed reference genes (TIP41 and APT1) in cannabis. These markers will be useful in future researches exploring cannabis defense pathways.

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Control of Postharvest Decay of Apple Fruit with Candida saitoana and Induction of Defense Responses

Phytopathology ◽

10.1094/phyto.2003.93.3.344 ◽

2003 ◽

Vol 93 (3) ◽

pp. 344-348 ◽

Cited By ~ 107

Author(s):

Ahmed El Ghaouth ◽

Charles L. Wilson ◽

Michael Wisniewski

Keyword(s):

Botrytis Cinerea ◽

Defense Responses ◽

Apple Fruit ◽

Antagonistic Activity ◽

Systemic Resistance ◽

Induce Systemic Resistance ◽

Lesion Development ◽

Glucanase Activity ◽

Induce Resistance ◽

Lag Period

The ability of Candida saitoana to induce systemic resistance in apple fruit against Botrytis cinerea was investigated. To separate the antagonistic activity of C. saitoana from its ability to induce resistance, the antagonist and the pathogen were applied in spatially separated wounds. In fresh apples, C. saitoana applied 0 or 24 h before inoculation with B. cinerea showed no effect on lesion development caused by B. cinerea. When applied 48 to 72 h preinoculation with B. cinerea, however, C. saitoana reduced lesion diameter by more than 50 and 70%, respectively, compared with wounding. C. saitoana had no effect on lesion development on stored apples, regardless of the lag period between yeast treatment and inoculation with B. cinerea. In addition to inducing systemic resistance, C. saitoana increased chitinase and β-1,3-glucanase activities with a higher accumulation in fresh than in stored apples. In fresh apples, the onset of systemic resistance to B. cinerea coincided with the increase in chitinase and β-1,3-glucanase activity in systemically protected tissue. These studies show that C. saitoana is capable of inducing systemic resistance in apple fruit and indirectly suggest that antifungal hydrolases are involved in the observed systemic protection.

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