A gene to defeat grey mould: the number one enemy of over 200 plant species

An international study, coordinated by the Department of Biology and Biotechnology "Charles Darwin" of Sapienza University of Rome, identifies a new gene capable of combatting the invasion of fungal pathogens and in particular of Botrytis cinerea, responsible for grey mould in numerous plant species including vines, tomatoes and strawberries. The results have been published on the journal Molecular Plant Pathology

In the agronomic sector, plant pathogens represent a serious problem as they cause huge losses of crops and in some cases intoxicate foods of plant origin by secreting mycotoxins that are also potentially dangerous to human health.

One of the most common and well-known invaders is botrytis, also known as grey mould, which covers the surface of the leaves and causes them to dry and wither quickly.

To limit the damage caused by these pathogens, the most widely adopted approach is the extensive use of pesticides, with serious consequences for soil and groundwater pollution. An eco-compatible solution involves plant biotechnology strategies aimed at achieving greater resistance of plants to environmental microbes, the so-called genetic. Its application is limited, however, by the lack of knowledge of defence genes that plants use to activate immune defence mechanisms.

In this field, an important element has been added thanks to the synergical interaction of plant physiologists and biochemists belonging to the Departments of Biology and Biotechnology "Charles Darwin" and the Department of Biochemical Sciences of Sapienza Universiy together with reasearcher from French universities and institutions.

In the study published on the journal Molecular Plant Pathology, the team of researchers coordinated by Vincenzo Lionetti and Daniela Bellincampi identified Arabidopsis thaliana as a new defence gene against fungal pathogens, in particular Botrytis cinerea, a necrotrophic fungus capable of causing severe crop losses in more than 200 plant species, including those of great agronomic importance, such as vine, tomato and strawberry.

"The gene, called AtPME17, has been demonstrated to play a central role in the plant's immune defence mechanisms", says Vincenzo Lionetti of the Department of Biology and Biotechnology "Charles Darwin". The encoding enzyme, called Pectin Methylsterase17, can modulate the methylation status of pectins, important components of the cell wall, where the first contact between the plant and pathogens occurs. The enzymatic activity strengthens the cell wall locally, favouring the activation of the immune response in the plant and blocking, at the site of infection, the invasion of the fungus."

The results of the study are useful for a wide range of applications in the biotechnological field, suggest that the gene identified could be used in the genetic improvement of plants of agronomic interest for the development of varieties with improved resistance to a large number of infectious diseases, without the use of pesticides dangerous for human health and the environment.

References:

AtPME17 is a functional Arabidopsis thaliana pectin methylesterase regulated by its PRO region that triggers PME activity in the resistance to Botrytis cinerea − Daniele Del Corpo, Maria R. Fullone, Rossella Miele, Mickaël Lafond, Daniela Pontiggia, Sacha Grisel, Sylvie Kieffer‐Jaquinod, Thierry Giardina, Daniela Bellincampi and Vincenzo Lionetti − Molecular Plant Pathology, 2020. DOI https://doi.org/10.1111/mpp.13002