The endopolygalacturonase gene Bcpg1 is required for full virulence of Botrytis cinerea.

TEN HAVE, A, MULDER W, VISSER J AND VAN KAN JAL

MOLECULAR PLANT-MICROBE INTERACTIONS

Año: 1998 vol. 11 p. 1009 - 1016

0894-0282

Botrytis cinerea, a fungus that causes diseases in over 200plant species, secretes a number of endopolygalacturo-nases that have been suggested to be involved in patho-genesis. However, so far the corresponding genes have notbeen isolated from this fungus. We cloned Bcpg1, encodingendopolygalacturonase, with the pgaII gene from Asper-gillus niger as a heterologous probe. The Bcpg1 gene is ex-pressed to similar levels in liquid cultures of B. cinereacontaining either 1% polygalacturonic acid or 1% sucrose,and is expressed during infection of tomato leaves. TheBcpg1 gene was eliminated by partial gene replacement,and the resulting mutants were tested for virulence on to-mato leaves and fruits, as well as on apple fruits. Althoughthe mutants were still pathogenic and displayed similarprimary infections when compared with control strains, asignificant decrease in secondary infection, i.e., growth ofthe lesion beyond the inoculation spot, was observed on allthree host tissues. These results indicate that the Bcpg1gene is required for full virulence.