%0 Journal Article
%T Adding injury to insult: pathogen detection and responses
%A Edward E Farmer
%J Genome Biology
%D 2000
%I BioMed Central
%R 10.1186/gb-2000-1-2-reviews1012
%X Considerable space in the genomes of most higher organisms is devoted to encoding the machinery necessary for perceiving pathogens and signaling from this perception to trigger defense gene expression. Plants are no exception, since they are subject not only to attack by microbial pathogens but also by myriad invertebrates and vertebrates. They must also be able to deal with environmentally imposed stresses such as drought and physical injury. The question is: what proportion of the genome encodes products involved only in pathogen defense signaling, and what proportion is involved in less specific survival mechanisms that also protect against physical injury? Genomic approaches are rapidly shedding light on this issue and already offer part of the answer, yielding a new understanding of the strategies employed by attacking organisms. An element of the story comes from a new study [1] of genes rapidly activated or repressed when a transgenic plant cell suspension culture perceives a component of a fungal pathogen. Additional evidence comes from a number of studies of plant gene expression responses to a number of different pathogens and predators.Durrant et al. [1] used transgenic tobacco cells expressing the tomato Cf-9 resistance gene, which enables the cells to respond to the Avr9 peptide elicitor produced by specific races of the fungal pathogen Cladosporium fulvum. On perception of the elicitor, defense responses are rapidly activated. Along with other well-established cell-suspension culture systems [2], Cf-9-tobacco cell cultures have already proven to be a useful tool for pharmacological studies of early events in signal transduction triggered by pathogen-derived elicitors [3]. The novelty of the study by Durrant et al. [1] is, in part, due to the fact that the authors isolated rapidly regulated cDNAs rather than downstream defense genes, thus giving new information on signal transduction in response to elicitation.The Avr9 elicitor peptide (in the intercell
%U http://genomebiology.com/2000/1/2/reviews/1012