Agroecology 3 min

Enzyme pair responsible for prompting fungal infection in plants

PRESS RELEASE - Understanding the mechanisms through which pathogenic fungi infect plants is essential to reduce the use of fungicides. An important and unexpected discovery in the field was made while investigating the bioproduction of citrus aromas using enzymes from phytopathogenic fungi. Researchers from INRAE, CNRS and CEA discovered that a particular pair of enzymes play a major role in the infection mechanism of these fungi. The results were published on 21 December in Science Advances.

Published on 22 December 2022

illustration Enzyme pair responsible for prompting fungal infection in plants
© Pixabay

While working on an applied research project funded by the French National Research Agency, a team of researchers* made an unexpected discovery. The aim of the FUNTASTIC project was to identify enzymes in fungi that are naturally capable of producing citrus-scented molecules to be used in perfumes.

The team observed that a pair of enzymes systematically appeared together—an enzyme A (alcohol oxidase) and an enzyme B (peroxidase), essential for enzyme A activation. The systematic presence of this tandem of oxidative enzymes (A+B) in certain phytopathogenic fungi—Colletotrichum, Magnaporthe—intrigued the scientists.

As a result, a multidisciplinary consortium working at the interface between enzymology and the biology of phytopathogenic fungi was set up by INRAE researchers, with the participation of experts from the CNRS and the CEA, as well as other teams from Japan, Spain and Canada. A model pathogenic fungus—Colletotrichum orbiculare—was selected to study the impact of this enzyme tandem on the fungus’ virulence.

The result was clear: without either enzyme A or enzyme B, the fungus was no longer able to infect the plant. This means that the A+B pair is required for the pathogenicity of the fungus. Both enzymes are co-secreted by the fungus and co-localised at the point of entry, before plant penetration. More specifically, these two enzymes must be present to modify certain compounds1 on the surface of the plant's leaves, at the cuticle, its outer defensive barrier.

Furthermore, the research shows that the aldehyde resulting from the enzymatic reaction acts as a signal, prompting the fungus to penetrate deeper plant tissue.

This study provides valuable data on the infection strategies of these pathogenic fungi. A better understanding of their highly complex and finely regulated mechanisms could ultimately lead to the development of new crop protection strategies.

1Long-chain aliphatic alcohols form a protective barrier on the surface of the leaf against a wide range of pathogens, such as fungi, bacteria and insects.

Aggressive fungi
Colletotrichum and Magnaporthe fungi presenting this particular enzyme tandem are the causative agents of widespread plant diseases such as anthracnose and blast. These diseases have a major impact on crop yield, in vegetables, fruit and cereals. To puncture the plant cuticle, fungal spores form an infection structure—called the appressorium—which exerts mechanical pressure against the plant tissue. Although much studied internationally, the underlying molecular mechanisms are not yet fully understood.

Bastien Bissaro†, Sayo Kodama†, Takumi Nishiuchi, Anna Maria Díaz-Rovira, Hayat Hage, David Ribeaucourt, Mireille Haon, Sacha Grisel, A. Jalila Simaan, Fred Beisson, Stephanie M. Forget, Harry Brumer, Marie-Noëlle Rosso, Victor Guallar, Richard O ́Connell, Mickaël Lafond, Yasuyuki Kubo* and Jean-Guy Berrin*. Tandem metalloenzymes gate plant cell entry by pathogenic fungi. Science Advances. DOI: 10.1126/sciadv.ade9982

*Fungal Biodiversity and Biotechnology Joint Research Unit (INRAE/AMU), The Biology and Risk Management in Agriculture Joint Research Unit (INRAE/AgroParisTech/Université Paris-Saclay), Institute of Molecular Sciences of Marseille (CNRS/AMU/Centrale Marseille), The Aix-Marseille Institute of Biosciences and Biotechnologies (CNRS/AMU/CEA)


INRAE Press Office

Scientific contact

Jean-Guy Berrin Fungal Biodiversity and Biotechnology Joint Research Unit



Learn more


What is the origin of the deadly toxins in mushrooms?

PRESS RELEASE - Certain unrelated deadly fungi produce the same toxin, amanitin. Where this substance comes from, however, and how it is made, is unknown. INRAE scientists teamed up with the Kunming Institute of Botany in China to better understand the molecular processes behind the production of this toxin. Published in PNAS, these ground-breaking results expand our understanding of the metabolism of fungal toxins and offer new perspectives on their role in the environment.

16 May 2022


A plant-fungi partnership at the origin of terrestrial vegetation

PRESS RELEASE - 450 million years ago, the first plants left aquatic life. Researchers from the CNRS and the Université de Toulouse III - Paul Sabatier, in collaboration with INRAE, have succeeded in demonstrating that this colonisation of land by plants was made possible by a partnership between plants and fungi. Validating this 40-year-old hypothesis allows us to understand a stage that was crucial to the development of life on Earth. The study is published in Science on 21 May 2021.

20 May 2021


Large-scale genomics sheds light on the evolutionary history of mutualistic forest-dwelling fungi

PRESS RELEASE - Mutualistic fungi, known as mycorrhizae, play a major role in terrestrial ecosystems because they help plants acquire nutrients. However, how these fungi became symbionts was a mystery until now. Answers to this question have been provided by an international research consortium coordinated by INRAE and the Joint Genome Institute (US Department of Energy) to which the University of Lorraine and CNRS also contributed. The group analysed the genomes of 135 species of forest-dwelling fungi. The study's results clarify how fungi living as decomposers became plant symbionts over the course of evolution. These findings were published on October 12 in Nature Communications.

12 October 2020