Limits...
Genotypic and phenotypic versatility of Aspergillus flavus during maize exploitation.

Reverberi M, Punelli M, Scala V, Scarpari M, Uva P, Mentzen WI, Dolezal AL, Woloshuk C, Pinzari F, Fabbri AA, Fanelli C, Payne GA - PLoS ONE (2013)

Bottom Line: The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus.The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources.We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Biologia Ambientale, Università La Sapienza, Roma, Italy. massimo.reverberi@uniroma1.it

ABSTRACT
Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic).

Show MeSH
Scatter plot of the first two principal components from the Principal Coordinate Analysis of the carbon source utilization profiles of conidia conidia isolated from the four trophic phases (in vivo-IV, sapro-S, flask-F and chemo-C) after 24, 48, 72, 96 and 168 h of incubation.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3716879&req=5

pone-0068735-g002: Scatter plot of the first two principal components from the Principal Coordinate Analysis of the carbon source utilization profiles of conidia conidia isolated from the four trophic phases (in vivo-IV, sapro-S, flask-F and chemo-C) after 24, 48, 72, 96 and 168 h of incubation.

Mentions: The dissimilarity between the groups is summarized and visualized in Figure 2, where the plot obtained with Principal Coordinate Analysis is reported. The mycelia derived from the conidia harvested at completion of the four trophic phases are similar in their metabolism after 24 h of incubation (they are all reported in the same quadrant of the plot). The metabolic behaviour of the different trophic phases diverges with higher incubation times: the flask phase (F) is represented in the positive quadrant (top right), while conidia from chemo (C) phase are in the bottom right quadrant. Both in vivo (IV) and sapro (S) phases are on the left side of the plot and show some overlap at longer incubation times.


Genotypic and phenotypic versatility of Aspergillus flavus during maize exploitation.

Reverberi M, Punelli M, Scala V, Scarpari M, Uva P, Mentzen WI, Dolezal AL, Woloshuk C, Pinzari F, Fabbri AA, Fanelli C, Payne GA - PLoS ONE (2013)

Scatter plot of the first two principal components from the Principal Coordinate Analysis of the carbon source utilization profiles of conidia conidia isolated from the four trophic phases (in vivo-IV, sapro-S, flask-F and chemo-C) after 24, 48, 72, 96 and 168 h of incubation.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3716879&req=5

pone-0068735-g002: Scatter plot of the first two principal components from the Principal Coordinate Analysis of the carbon source utilization profiles of conidia conidia isolated from the four trophic phases (in vivo-IV, sapro-S, flask-F and chemo-C) after 24, 48, 72, 96 and 168 h of incubation.
Mentions: The dissimilarity between the groups is summarized and visualized in Figure 2, where the plot obtained with Principal Coordinate Analysis is reported. The mycelia derived from the conidia harvested at completion of the four trophic phases are similar in their metabolism after 24 h of incubation (they are all reported in the same quadrant of the plot). The metabolic behaviour of the different trophic phases diverges with higher incubation times: the flask phase (F) is represented in the positive quadrant (top right), while conidia from chemo (C) phase are in the bottom right quadrant. Both in vivo (IV) and sapro (S) phases are on the left side of the plot and show some overlap at longer incubation times.

Bottom Line: The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus.The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources.We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Biologia Ambientale, Università La Sapienza, Roma, Italy. massimo.reverberi@uniroma1.it

ABSTRACT
Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic).

Show MeSH