Biology subjects

Fiorin, G. L.

Publications and source records attributed to Fiorin, G. L..

3 recordsLinked to original sources

bioRxiv2025

A gnotobiotic system reveals multifunctional effector roles in plant-fungal pathogen dynamics

Plants host diverse microbiota that influence physiological processes and can enhance resilience against invading pathogens that, in turn, evolved effector proteins to manipulate host microbiota in their favor. However, the complexity of microbial communities and their interactions complicates mechanistic research on processes governing microbiota assembly and function. Gnotobiotic systems are valuable tools to study plant microbiota by reducing complexity and enabling controlled microbiota reconstitution experiments. Despite their utility, no gnotobiotic systems have been established to investigate the role of antimicrobial effector proteins in the interactions between plants, their microbiota, and fungal pathogens. Here, we present a refined gnotobiotic system designed to study these interactions, establishing protocols for infections with the fungal pathogen Verticillium dahliae across multiple host plants under sterile conditions. We demonstrate that a synthetic microbial community (SynCom) derived from a culture collection generated for this study can be applied in this system where it interferes with fungal infections. Additionally, using our gnotobiotic system we reveal that specific antimicrobial effectors of V. dahliae, like Ave1L2, contribute to fungal virulence in a microbiota-dependent manner, whereas other antimicrobial effectors, such as Ave1, seem to possess functions beyond microbiota manipulation.

plant biology↗

bioRxiv2024

Unveiling novel mechanisms of strobilurin resistance in the cacao pathogen Moniliophthora perniciosa

Witches broom disease (WBD) is a major constraint for cacao production in the Americas. The severe socioeconomic impact of WBD encouraged the evaluation of different control strategies, including the use of strobilurin fungicides. These molecules inhibit mitochondrial respiration, thus impairing ATP generation and leading to oxidative stress. These chemicals, however, have proven ineffective against the WBD pathogen Moniliophthora perniciosa. Here, we demonstrate that M. perniciosa tolerates high concentrations of strobilurins under in vitro conditions and highlight a set of molecular alterations that correlate with strobilurin tolerance in this fungus. Short-term exposure of M. perniciosa to the commercial strobilurin azoxystrobin led to the up-regulation of genes encoding enzymes of the glyoxylate cycle, gluconeogenesis, and fatty acid and amino acid catabolism, indicating that the fungal metabolism is remodeled to compensate for reduced ATP production. Furthermore, cell division, ribosome biogenesis, and sterol metabolism were repressed, which agrees with the impaired mycelial growth on azoxystrobin. Genes associated with cellular detoxification and response to oxidative stress (e.g., cytochrome P450s, membrane transporters and glutathione s-transferases) were strongly induced by the drug and represent potential strategies used by the pathogen to mitigate the toxic effects of the fungicide. Remarkably, exposure of M. perniciosa to azoxystrobin resulted in the spontaneous generation of a mutant with increased resistance to strobilurin. Comparative genomics and transcriptomics revealed alterations that may explain the resistance phenotype, including a large deletion in a putative transcriptional regulator and significant changes in the mutant transcriptome. Overall, this work provides important advances towards a comprehensive understanding of the molecular basis of strobilurin resistance in a tropical fungal pathogen. This is a fundamental step to efficiently employ these fungicides in agriculture and to prevent the emergence of strobilurin resistance.

microbiology↗

bioRxiv2021

Adaptive evolution of Moniliophthora PR-1 proteins towards its pathogenic lifestyle

Moniliophthora perniciosa and Moniliophthora roreri are hemibiotrophic fungi that harbor a large number of Pathogenesis-Related 1 genes, many of which are induced in the biotrophic interaction with Theobroma cacao. Here, we provide evidence that the evolution of PR-1 in Moniliophthora was adaptive and potentially related to the emergence of the parasitic lifestyle in this genus. Phylogenetic analysis revealed conserved PR-1 genes, shared by many Agaricales saprotrophic species, that have diversified in new PR-1 genes putatively related to pathogenicity in Moniliophthora, as well as in recent specialization cases within both species. PR-1 families in Moniliophthora with higher evolutionary rates exhibit induced expression in the biotrophic interaction and positive selection clues, supporting the hypothesis that these proteins accumulated adaptive changes in response to host-pathogen arm race. Furthermore, we show that the highly diversified MpPR-1 genes are not induced by two phytoalexins, suggesting detoxification might not be their main function as proposed before.

evolutionary biology↗