Multidrug resistance of Botrytis cinerea associated with its adaptation to plant secondary metabolites

Abstract

Fungicides are an effective way to control gray mold of grapes, but the pathogen Botrytis cinerea can develop resistance, overcoming the effectiveness of a fungicide that is repeatedly applied. More importantly, the emergence of multidrug resistance (MDR) in the field, where multiple fungicides with different modes of action simultaneously lose their efficacies, is a significant concern. MDR is associated with ATP-binding cassette (ABC) transporters of the pathogen, and certain plant secondary metabolites (PSMs) stimulate the upregulation of ABC transporters, we hypothesized that the pathogen’s preadaptation to PSMs might contribute to MDR development. To test this in B. cinerea, ten PSMs, namely, resveratrol, reserpine, chalcone, flavanone, eugenol, farnesol, anethene, camptothecin, salicylic acid, and psoralen, were selected based on their association with ABC transporters involved in fungicide resistance. B. cinerea strain B05.10 was continuously transferred for 15 generations on potato dextrose agar amended with a PSM (PDAP), and sensitivities to PSMs and fungicides were examined on the 5th, 10th, and 15th generations. RNA was extracted from B. cinerea from the selected generations. After 15 generations of culture transfers, an up-regulation was observed in the expression of ABC transporter-encoding genes BcatrB, BcatrD, and BcatrK using quantitative polymerase chain reaction (qPCR). This upregulation was found to contribute to MDR of B. cinerea against two or more fungicides, among azoxystrobin, boscalid, fludioxonil, difenoconazole, prochloraz, and pyrimethanil. This finding was confirmed through genetic transformation. The decreased sensitivity of B. cinerea to fungicides was confirmed as a subsequent MDR phenotype after exposure to camptothecin, flavanone, and resveratrol. Besides, transcriptome analysis also revealed the upregulation of transcription factors related to ABC expression following resveratrol exposure. This suggests that PSMs contributed to inducing preadaptation of B. cinerea, leading to subsequent MDR. IMPORTANCE The emergence of MDR in plant pathogens is a threat to plant disease management and leads to the use of excessive fungicides. Botrytis cinerea is of particular concern because its MDR has widely emerged in the field. Understanding its genesis is the first step for controlling MDR. In this study, the contribution of PSMs to MDR has been examined. Effective management of this pathogen in agroecosystems relies on a better understanding of how it copes with phytochemicals or fungicides.

Molecular Basis of Yeasts Antimicrobial Activity—Developing Innovative Strategies for Biomedicine and Biocontrol

“…Due to their highly versatile metabolism, the yeasts can use as carbon source a wide range of carbohydrates including disaccharides and monosaccharides. As an example, the red yeast S. roseus inhibits the growth of B. cinerea, a plant pathogen that causes many agricultural loses due to its high resistance to classical fungicides used in the current agricultural practices [125], by limiting its access to glucose and blocking the conidial germination [126]. A similar effect was observed in the case of a R. mucilaginosa strain isolated from the surface of apple fruits.…”

2-Heptanol inhibits Botrytis cinerea by accelerating amino acid metabolism and retarding membrane transport

“…ABC transporters facilitate the translocation of not only a wide array of nutrients but also exogenous drugs, with certain transporters playing a pivotal role in cell growth and antifungal resistance ( Viglas and Olejnikova, 2021 ). To date, 14 ABC transporters ( BcatrA to BcatrN ) have been characterized, and of these, the BcatrB , BcatrD , and BcatrK genes are implicated in the multidrug resistance of B. cinerea , primarily functioning in the expulsion of toxic fungi compounds ( Stefanato et al., 2009 ; Wu et al., 2024 ). Research has revealed that antifungal agents impinge on the functionality of pathogen ABC transporters by modulating ABC gene expression ( Wu et al., 2024 ).…”

“…To date, 14 ABC transporters ( BcatrA to BcatrN ) have been characterized, and of these, the BcatrB , BcatrD , and BcatrK genes are implicated in the multidrug resistance of B. cinerea , primarily functioning in the expulsion of toxic fungi compounds ( Stefanato et al., 2009 ; Wu et al., 2024 ). Research has revealed that antifungal agents impinge on the functionality of pathogen ABC transporters by modulating ABC gene expression ( Wu et al., 2024 ). Our investigations indicate that BcatrB and BcatrD genes were significantly downregulated following 2-HE treatment by 2.71 and 1.16 times, respectively, suggesting impaired B. cinerea ability to extrude 2-HE as a toxic substance.…”