Plant pathogenesis-related proteins: molecular mechanisms of gene expression and protein function.
Higher plants accumulate several kinds of "pathogenesis-related (PR)" proteins in response to infection by pathogens such as fungi or viruses. Gene expression of one group of PR proteins is known to be mediated by phytohormone ethylene. Here we describe the signal transduction system from the ethylene receptor ETR to transcription factors, ERFs. Ethylene-inducible PR genes are expressed constitutively in roots and cultured cells even when are not infected. We discuss the mechanisms of this pathogen-independent expression of PR genes and describe recent findings in the study of molecular mechanisms of antifungal activities of the PR proteins. Genes of PR-1 and -5 proteins have now been identified in the genomes of various species of organisms, including humans and nematodes. PR proteins may contribute to the innate immunity of plants as well as to that of other organisms.
Kitajima
S
S
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan.
Sato
F
F
D000595:Amino Acid Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D010944:Plants / Q000276:immunology / Q000382:microbiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D010940:Plant Proteins; C093680:ethylene-responsive element binding protein