Cerato-platanin (CP) is a non-catalytic protein with a double-psi-beta-barrel fold located in the cell wall of the phytopathogenic fungus Ceratocystis platani, the causal agent of the canker stain disease of plane trees. CP is the first member of a protein family named the “cerato-platanin family” (Pfam PF07249), which comprises proteins well known for resistance-inducing activity in plants. The biological role of these proteins in fungal life is unknown. However, we hypothesize that CP can have a dual role: a structural role in the fungal cell wall due to the ability to bind chitin; and a role in the fungus-plant interaction due to the ability to weaken cellulosic materials, that has also led us to propose CP as a novel one-domain expansin-like protein. CP is released during the growth of C. platani and induces defence-related responses in host and non-host plants, including tobacco and soybean. CP seems to act as a pathogen-associated molecular pattern (PAMP). Results obtained on plane (Platanus acerifolia) leaves have shown that CP is able to induce early production of hydrogen peroxide and nitric oxide, overexpression of defence-related genes, phytoalexins synthesis, programmed cell death and localised resistance. However, CP does not penetrate the leaf cuticle, and thus triggers defences with an undefined molecular mechanism. We have found that in vitro CP strongly interacts with hydrophobic inanimate surfaces and undergoes unfolding. In vivo the interaction of CP with the host cuticle could thus be responsible for the PAMP-like activity. The plant model Arabidopsis is being useful to clarify this mechanism.
Biological role in fungal life and molecular mechanism of action: two intriguing topics for the fungal PAMP cerato-platanin
BERNARDI, RODOLFO;
2013-01-01
Abstract
Cerato-platanin (CP) is a non-catalytic protein with a double-psi-beta-barrel fold located in the cell wall of the phytopathogenic fungus Ceratocystis platani, the causal agent of the canker stain disease of plane trees. CP is the first member of a protein family named the “cerato-platanin family” (Pfam PF07249), which comprises proteins well known for resistance-inducing activity in plants. The biological role of these proteins in fungal life is unknown. However, we hypothesize that CP can have a dual role: a structural role in the fungal cell wall due to the ability to bind chitin; and a role in the fungus-plant interaction due to the ability to weaken cellulosic materials, that has also led us to propose CP as a novel one-domain expansin-like protein. CP is released during the growth of C. platani and induces defence-related responses in host and non-host plants, including tobacco and soybean. CP seems to act as a pathogen-associated molecular pattern (PAMP). Results obtained on plane (Platanus acerifolia) leaves have shown that CP is able to induce early production of hydrogen peroxide and nitric oxide, overexpression of defence-related genes, phytoalexins synthesis, programmed cell death and localised resistance. However, CP does not penetrate the leaf cuticle, and thus triggers defences with an undefined molecular mechanism. We have found that in vitro CP strongly interacts with hydrophobic inanimate surfaces and undergoes unfolding. In vivo the interaction of CP with the host cuticle could thus be responsible for the PAMP-like activity. The plant model Arabidopsis is being useful to clarify this mechanism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
