Open AccessHomoserine and asparagine are host signals that trigger in planta expression of a pathogenesis gene in Nectria haematococca
Author(s) -
Zhennai Yang,
Linda Rogers,
Yuanda Song,
Wenjin Guo,
P.E. Kolattukudy
Publication year - 2005
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0500312102
Subject(s) - biology , asparagine , host (biology) , fusarium solani , gene , virulence , gene expression , pathogen , pathogenesis , amino acid , genetics , microbiology and biotechnology , immunology
Some pathogenesis-related genes are expressed in fungi only when the pathogen is in the host, but the host signals that trigger these gene expressions have not been identified. Virulent Nectria haematococca infects pea plants and requires either pelA, which is induced by pectin, or pelD, which is induced only in planta. However, the host signal(s) that trigger pelD expression was unknown. Here we report the isolation of the host signals and identify homoserine and asparagine, two free amino acids found in uniquely high levels in pea seedlings, as the pelD-inducing signals. N. haematococca has evolved a mechanism to sense the host tissue environment by using the high levels of two free amino acids in this plant, thereby triggering the expression of pelD to assist the pathogenic process.