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INRAE

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Last update: May 2021

Menu Logo Principal Plant pathology unit - INRA AVIGNON

Pathologie vegetale

Zone de texte éditable et éditée et rééditée

Biological control

Durability of efficacy of biological control agents against Botrytis cinerea

Estimate of potential resistance of Botrytis cinerea to biofungicides

The potential resistance of Botrytis cinerea to biofungicides was studied during a thesis defended in 2009

  • Ajouz, S. 2009. Estimation du potentiel de résistance de Botrytis cinerea à des biofongicides. Thesis supervised by Bardin, M. (MISTRAL team) and El Maataoui, M. (University of Avignon). The pdf file of the thesis can be downloaded on the website "TEL", multidisciplinary theses server. Some chapters are written in English.

Striking result of this study:

  • This study provides evidence that a fungal plant pathogen is able to gradually build-up resistance to an antibiotic (pyrrolnitrin) produced by a biocontrol agent. However, the high level of resistance to pyrrolnitrin has resulted in a high fitness cost.

The loss of efficacy of biocontrol agents may result from:

  • the selection of isolates of the pathogen existing in natural populations and with reduced susceptibility to the biological agent protection
  • the ability of the pathogen to produce mutants with reduced susceptibility to the agent of biological protection under the selection pressure exerted by the continuous use of the product.

The study has been focused on the antibiotic pyrrolnitrin produced by various bacteria described as potential biological control agents against B. cinerea. The results on this topic concern:

  • frequency and mechanisms of resistance in B. cinerea
  • future of "overcoming" strains of B. cinerea

Frequency and mechanisms of resistance in B. cinerea

  • evidence in natural populations of B. cinerea of isolates with less sensitivity to the pyrrolnitrin antibiotic produced by biological control agents
  • relationship between the slightest sensitivity to pyrrolnitrin and multidrug resistance of B. cinerea isolates
  • rapid development of mutants with high levels of resistance to the pyrrolnitrin for some isolates in experimental conditions in vitro
  • relation between the high resistance to pyrrolnitrin and resistance to botryticides
    • Ajouz, S., Nicot, P. C. Bardin, M. 2010. Adaptation to pyrrolnitrin in Botrytis cinerea and cost of resistance. Plant Pathology, 59, 556-566.
    • Ajouz, S., Walker, A. S., Fabre, F. , Leroux, P.,  Nicot, P. C. and Bardin, M. 2011. Variability of Botrytis cinerea sensitivity to pyrrolnitrin, an antibiotic produced by biological control agents. BioControl, 56, 353-363.
    • Fillinger-David, S. H., Ajouz, S., Nicot, P., Leroux, P., Bardin, M. 2012. Functional and structural comparison of pyrrolnitrin- and iprodione-induced modifications in the class III histidine-kinase Bos1 of Botrytis cinerea. Plos One, 7, e42520.

Click on the figures to enlarge

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Future of "overcoming" strains

  • high fitness cost for the resistant isolates in absence of antibiotic pressure compared to sensitive isolates: evidence of a decrease of the mycelial growth  and sporulation in vitro and reduced aggressiveness on plant tissues (tomato and apple)
  • comparison of the cytohistological development of resistant and sensitive isolates to the antibiotic in planta: no spread of the mycelium throughout the petiole and changes of mycelial structures for the resistant isolate
    • Ajouz, S., Bardin, M., Nicot, P.C., and El Maataoui, M. 2011. Comparison of the development in planta of a pyrrolnitrin-resistant mutant of Botrytis cinerea and its sensitive wild-type parent isolate. European Journal of Plant Pathology, 129, 31-42.

Click on the figures to enlarge

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Ajouz, S., Bardin, M., Nicot, P.C., and El Maataoui, M. 2011. Comparison of the development in planta of a pyrrolnitrin-resistant mutant of Botrytis cinerea and its sensitive wild-type parent isolate. European Journal of Plant Pathology, 129, 31-42

© Ajouz  - INRA PACA Avignon

Development of biocontrol agents against B. cinerea

  • Selection of bacteria and fungi efficent against B. cinerea
  • Development of strain-specific markers for the detection of the biocontrol agent Microdochium dimerumL13
    • Bardin, M., Bourgeay, J.-F., Pascal, M., Nicot, P. C. (2018). Effect of drench application of biocontrol preparations on tomato plants against Botrytis cinerea and Oidium neolycopersici. IOBC WPRS Bulletin, 135, 5-6. http://prodinra.inra.fr/record/453318
    • Bardin, M., Comby, M., Lenaerts, R., Nicot, P. 2013. Diversity in susceptibility of Botrytis cinerea to biocontrol products inducing plant defence mechanisms. IOBC WPRS Bulletin, 88, 45-49.
    • Bardin, M., Comby, M., Troulet, C., Nicot, P. 2013. Relationship between the aggressiveness of Botrytis cinerea on tomato and the efficacy of biocontrol. IOBC WPRS Bulletin, 86, 163-168.
    • Bardin, M., Fargues, J., Nicot, P. (2008). Compatibility between biopesticides used to control grey mould, powdery mildew and whitefly on tomato. Biological Control, 46, 476-483. DOI : 10.1016/j.biocontrol.2008.05.012PANISThttps://prodinra.inra.fr/record/21483
    • Bouaoud, Y., Troulet, C., Foughalia, A., Berge, O., Aissat, K., Bardin, M.  (2018). A multi-criteria approach for the selection of efficient biocontrol agents against Botrytis cinerea on tomato in Algeria. BioControl, 63, 299-311. DOI : 10.1007/s10526-017-9851-7http://prodinra.inra.fr/record/412555
    • Bouaoud, Y., Troulet, C., Berge, O., Aissat, K., Bardin, M. (2018). Diversity in the susceptibility of Botrytis cinerea strains to the biological control agent Pseudomonas helmanticensis. IOBC WPRS Bulletin, 133, 100-104. http://prodinra.inra.fr/record/434755
    • Boukaew, S., Prasertsan, P., Troulet, C., Bardin, M.  (2017). Biological control of tomato gray mold caused by Botrytis cinerea by using Streptomyces spp. BioControl, 62, 793-803. DOI : 10.1007/s10526-017-9825-9http://prodinra.inra.fr/record/400612
    • Nicot, P. C., Stewart, A., Bardin, M., Elad, Y. 2016. Biological control and biopesticide suppression of Botrytis-incited diseases. In: Sabine Fillinger, Yigal Elad (Eds), Botrytis – the fungus, the pathogen and its management in agricultural systems (p. 165-187). Switzerland: Springer International Publishing. DOI : 10.1007/978-3-319-23371-0_9https://prodinra.inra.fr/record/340226
    • Sadfi-Zouaoui, N., Hannachi, I., Andurand, D., Essghaier, B., Boudabous, A., and Nicot, P. 2008. Biological control of Botrytis cinerea on stem wounds with moderately halophilic bacteria. World Journal of Microbiology & Biotechnology 24, 2871-2877.