Human-Mediated Gene Flow Contributes to Metapopulation Genetic Structure of the Pathogenic Fungus Alternaria alternata from Potato

Meng, Jing-Wen; He, Dun-Chun; Zhu, Weihua; Yang, Lina; Wu, E‐Jiao; Xie, Jiahui; Shang, Li‐Ping; Zhan, Jiasui

doi:10.3389/fpls.2018.00198

“…isolates are Mat-1 and 115 isolates are Mat-2. Detailed information on pathogen collection, isolation, DNA extraction, SSR assay and mating type determination can be found in the previous publications [25,58]. Briefly, infected leaves with typical early blight symptoms were collected randomly from potato plants separated by 1-2 m with only one infected leaf being sampled from each collection point (plant).…”

Section: Alternaria Alternata Collectionmentioning

confidence: 99%

Cross-resistance of the pathogenic fungus Alternaria alternata to fungicides with different modes of action

Yang

¹

,

He

²

,

Ouyang

³

et al. 2019

Preprint

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Background: Cross-resistance, a phenomenon that a pathogen resists to one antimicrobial compound also resists to one or several other compounds, is one of major threats to human health and sustainable food production. It usually occurs among antimicrobial compounds sharing the mode of action. In this study, we determined the sensitivity profiles of Alternaria alternata , a fungal pathogen which can cause diseases in many crops to two fungicides (mancozeb and difenoconazole) with different mode of action using a large number of isolates (234) collected from seven potato fields across China. Results: We found that pathogens could also develop cross resistance to fungicides with different modes of action as indicated by a strong positive correlation between mancozeb and difenoconazole tolerances to A. alternata . We also found a positive association between mancozeb tolerance and aggressiveness of A. alternata , suggesting no fitness penalty of developing mancozeb resistance in the pathogen and hypothesize that mechanisms such as antimicrobial compound efflux and detoxification that limit intercellular accumulation of natural/synthetic chemicals in pathogens might account for the cross-resistance and the positive association between pathogen aggressiveness and mancozeb tolerance. Conclusions: The detection of cross-resistance among different classes of fungicides suggests that the mode of action alone may not be an adequate sole criterion to determine what components to use in the mixture and/or rotation of fungicides in agricultural and medical sects. Similarly, the observation of a positive association between the pathogen’s aggressiveness and tolerance to mancozeb suggests that intensive application of site non-specific fungicides might simultaneously lead to reduced fungicide resistance and enhanced ability to cause diseases in pathogen populations, thereby posing a greater threat to agricultural production and human health. In this case, the use of evolutionary principles in closely monitoring populations and the use of appropriate fungicide applications are important for effective use of the fungicides and durable infectious disease management.

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“…The fields where the pathogen samples were collected were not spayed with azoxystrobin. Therefore, the fungicide resistance observed in the study likely represents the true pattern of the local metapopulations constantly experiencing extinction and recolonization [63,64], indicating that the pathogens in different regions should be treated with different formulations of the fungicide for an improved economic and ecological benefit [65].…”

Section: Sources Of Genetic Variation Contributing To Azoxystrobin Admentioning

confidence: 99%

Temperature-Mediated Plasticity Regulates the Adaptation of Phytophthora infestans to Azoxystrobin Fungicide

Lurwanu

¹

,

Wang

²

,

Waheed

³

et al. 2020

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Fungicide is one of the main approaches used in agriculture to manage plant diseases for food production, but their effectiveness can be reduced due to the evolution of plant pathogens. Understanding the genetics and evolutionary processes responsible for the development of fungicide resistance is a key to food production and social sustainability. In this study, we used a common garden experiment to examine the source of genetic variation, natural selection, and temperature contributing to the development of azoxystrobin resistance in Phytophthora infestans and infer sustainable ways of plant disease management in future. We found that plasticity contributed to ~40% of phenotypic variation in azoxystrobin sensitivity while heritability accounted for 16%. Further analysis indicated that overall population differentiation in azoxystrobin sensitivity (QST) was significantly greater than the overall population differentiation in simple sequence repeat (SSR) marker (FST), and the P. infestans isolates demonstrated higher level of azoxystrobin sensitivity at the higher experimental temperature. These results suggest that changes in target gene expression, enzymatic activity, or metabolic rate of P. infestans play a more important role in the adaptation of the pathogen to azoxystrobin resistance than that of mutations in target genes. The development of azoxystrobin resistance in P. infestans is likely driven by diversifying selection for local adaptation, and elevated temperature associated with global warming in the future may increase the effectiveness of using azoxystrobin to manage P. infestans. The sustainable approaches for increasing disease control effectiveness and minimizing the erosion of the fungicide efficacy are proposed.

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“…Among these, 119 isolates are Mat-1 and 115 isolates are Mat-2. Detailed information on pathogen collection, isolation, DNA extraction, SSR assay and mating type determination can be found in the previous publications [25,26]. Briefly, infected leaves with typical early blight symptoms were collected randomly from potato plants separated by 1-2 m with only one infected leaf being sampled from each collection point (plant).…”

Section: Alternaria Alternata Collectionmentioning

confidence: 99%

Cross-resistance of the pathogenic fungus Alternaria alternata to fungicides with different modes of action

Yang

¹

,

He

²

,

Ouyang

³

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Background: Cross-resistance, a phenomenon that a pathogen resists to one antimicrobial compound also resists to one or several other compounds, is one of major threats to human health and sustainable food production. It usually occurs among antimicrobial compounds sharing the mode of action. In this study, we determined the sensitivity profiles of Alternaria alternata , a fungal pathogen which can cause diseases in many crops to two fungicides (mancozeb and difenoconazole) with different mode of action using a large number of isolates (234) collected from seven potato fields across China. Results: We found that pathogens could also develop cross resistance to fungicides with different modes of action as indicated by a strong positive correlation between mancozeb and difenoconazole tolerances to A. alternata . We also found a positive association between mancozeb tolerance and aggressiveness of A. alternata , suggesting no fitness penalty of developing mancozeb resistance in the pathogen and hypothesize that mechanisms such as antimicrobial compound efflux and detoxification that limit intercellular accumulation of natural/synthetic chemicals in pathogens might account for the cross-resistance and the positive association between pathogen aggressiveness and mancozeb tolerance. Conclusions: The detection of cross-resistance among different classes of fungicides suggests that the mode of action alone may not be an adequate sole criterion to determine what components to use in the mixture and/or rotation of fungicides in agricultural and medical sects. Similarly, the observation of a positive association between the pathogen’s aggressiveness and tolerance to mancozeb suggests that intensive application of site non-specific fungicides might simultaneously lead to reduced fungicide resistance and enhanced ability to cause diseases in pathogen populations, thereby posing a greater threat to agricultural production and human health. In this case, the use of evolutionary principles in closely monitoring populations and the use of appropriate fungicide applications are important for effective use of the fungicides and durable infectious disease management.

show abstract

Human-Mediated Gene Flow Contributes to Metapopulation Genetic Structure of the Pathogenic Fungus Alternaria alternata from Potato

Cited by 22 publications

References 78 publications

Cross-resistance of the pathogenic fungus Alternaria alternata to fungicides with different modes of action

Cross-resistance of the pathogenic fungus Alternaria alternata to fungicides with different modes of action

Temperature-Mediated Plasticity Regulates the Adaptation of Phytophthora infestans to Azoxystrobin Fungicide

Cross-resistance of the pathogenic fungus Alternaria alternata to fungicides with different modes of action

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