Aspergillus flavus is a saprophytic cosmopolitan fungus, capable of infecting crops both pre-and post-harvest and exploiting different secondary metabolites, including aflatoxins. Aflatoxins are known carcinogens to animals and humans, but display no clear effect in host plants such as maize. In a previous study, we mined the genome of A. flavus to identify secondary metabolite clusters putatively involving the pathogenesis process in maize. We now focus on cluster 32, encoding for fungal effectors such as salicylate hydroxylase (SalOH), and necrosis-and ethylene-inducing proteins (npp1 domain protein) whose expression is triggered upon kernel contact. In order to understand the role of this genetic cluster in maize kernel infection, mutants of A. flavus, impaired or enhanced in specific functions (e.g., cluster 32 overexpression), were studied for their ability to cause disease. Within this frame, we conducted histological and histochemical experiments to verify the expression of specific genes within the cluster (e.g., SalOH, npp1), the production of salicylate, and the presence of its dehydroxylated form. Results suggest that the initial phase of fungal infection (2 days) of the living tissues of maize kernels (e.g., aleuron) coincides with a significant increase of fungal effectors such as SalOH and Npp1 that appear to be instrumental in eluding host defences and colonising the starch-enriched tissues, and therefore suggest a role of cluster 32 to the onset of infection.

Aspergillus flavus exploits maize kernels using an “orphan” secondary metabolite cluster / Antiga, L.; La Starza, S. R.; Miccoli, C.; D'Angeli, S.; Scala, V.; Zaccaria, M.; Shu, X.; Obrian, G.; Beccaccioli, M.; Payne, G. A.; Reverberi, M.. - In: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - ISSN 1661-6596. - 21:21(2020), pp. 1-17. [10.3390/ijms21218213]

Aspergillus flavus exploits maize kernels using an “orphan” secondary metabolite cluster

La Starza S. R.;D'angeli S.;Beccaccioli M.
;
Reverberi M.
Ultimo
2020

Abstract

Aspergillus flavus is a saprophytic cosmopolitan fungus, capable of infecting crops both pre-and post-harvest and exploiting different secondary metabolites, including aflatoxins. Aflatoxins are known carcinogens to animals and humans, but display no clear effect in host plants such as maize. In a previous study, we mined the genome of A. flavus to identify secondary metabolite clusters putatively involving the pathogenesis process in maize. We now focus on cluster 32, encoding for fungal effectors such as salicylate hydroxylase (SalOH), and necrosis-and ethylene-inducing proteins (npp1 domain protein) whose expression is triggered upon kernel contact. In order to understand the role of this genetic cluster in maize kernel infection, mutants of A. flavus, impaired or enhanced in specific functions (e.g., cluster 32 overexpression), were studied for their ability to cause disease. Within this frame, we conducted histological and histochemical experiments to verify the expression of specific genes within the cluster (e.g., SalOH, npp1), the production of salicylate, and the presence of its dehydroxylated form. Results suggest that the initial phase of fungal infection (2 days) of the living tissues of maize kernels (e.g., aleuron) coincides with a significant increase of fungal effectors such as SalOH and Npp1 that appear to be instrumental in eluding host defences and colonising the starch-enriched tissues, and therefore suggest a role of cluster 32 to the onset of infection.
2020
Aspergillus flavus; effectors; histology; maize kernel; Npp1; quercetin; salicylate hydroxylase; aflatoxins; Aspergillosis; Aspergillus flavus; catechols; crops; agricultural; disease resistance; gene expression regulation, plant; metabolic networks and pathways; mixed function oxygenases; organisms genetically modified; plant diseases; quercetin; salicylic acid; seeds; zea mays; multigene family
01 Pubblicazione su rivista::01a Articolo in rivista
Aspergillus flavus exploits maize kernels using an “orphan” secondary metabolite cluster / Antiga, L.; La Starza, S. R.; Miccoli, C.; D'Angeli, S.; Scala, V.; Zaccaria, M.; Shu, X.; Obrian, G.; Beccaccioli, M.; Payne, G. A.; Reverberi, M.. - In: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - ISSN 1661-6596. - 21:21(2020), pp. 1-17. [10.3390/ijms21218213]
File allegati a questo prodotto
File Dimensione Formato  
Antiga_Aspergillus-flavus_2020.pdf

accesso aperto

Note: Articolo rivista
Tipologia: Documento in Post-print (versione successiva alla peer review e accettata per la pubblicazione)
Licenza: Creative commons
Dimensione 3 MB
Formato Adobe PDF
3 MB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1554685
Citazioni
  • ???jsp.display-item.citation.pmc??? 3
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 4
social impact