Surface signaling in pathogenesis

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 92; no. 10; pp. 4080 - 4087
• Main Authors: Kolattukudy, P.E. (The Ohio State University, Columbus, OH.), Rogers, L.M, Li, D.X, Hwang, C.S, Flaishman, M.A
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 09-05-1995; National Acad Sciences; National Academy of Sciences
• Subjects: Amino Acid Sequence; ANATOMIA DE LA PLANTA; ANATOMIE VEGETALE; Animals; Appressoria; Base Sequence; Biochemistry; Botany; Carboxylic Ester Hydrolases - biosynthesis; CERAS; CIRE; Colletotrichum; DIFERENCIACION CELULAR; DIFFERENCIATION CELLULAIRE; ENFERMEDADES FUNGOSAS; ETHYLENE; Ethylenes - metabolism; ETILENO; EXPRESION GENICA; EXPRESSION DES GENES; Flowers & plants; Fungal spores; Fungi; Fusarium - pathogenicity; FUSARIUM SOLANI; Fusarium solani pisi; Genes; Genes, Plant; Germination; GLOMERELLA CINGULATA; Infections; MALADIE FONGIQUE; Metallothionein - chemistry; Mice; Mitosporic Fungi - pathogenicity; Molecular Sequence Data; Neurospora crassa - metabolism; PATHOGENESE; PATOGENESIS; Phosphorylation; Plant Physiological Phenomena; Plants - genetics; Plants - microbiology; PROTEINA QUINASA; PROTEINE KINASE; Ripening; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Signal Transduction; Space life sciences; Transcription factors; TRIACILGLICEROL LIPASA; TRIACYLGLYCEROL LIPASE; Virulence; Waxes; Waxes - metabolism; Xenopus
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.10.4080

Surface signaling plays a major role in fungal infection. Topographical features of the plant surface and chemicals on the surface can trigger germination of fungal spores and differentiation of the germ tubes into appressoria. Ethylene, the fruit-ripening hormone, triggers germination of conidia, branching of hyphae, and multiple appressoria formation in Colletotrichum, thus allowing fungi to time their infection to coincide with ripening of the host. Genes uniquely expressed during appressoria formation induced by topography and surface chemicals have been isolated. Disruption of some of them has been shown to decrease virulence on the hosts. Penetration of the cuticle by the fungus is assisted by fungal cutinase secreted at the penetration structure of the fungus. Disruption of cutinase gene in Fusarium solani pisi drastically decreased its virulence. Small amounts of cutinase carried by spores of virulent pathogens, upon contact with plant surface, release small amounts of cutin monomers that trigger cutinase gene expression. The promoter elements involved in this process in F. solani pisi were identified, and transcription factors that bind these elements were cloned. One of them, cutinase transcription factor 1, expressed in Escherichia coli, is phosphorylated. Several protein kinases from F. solani pisi were cloned. The kinase involved in phosphorylation of specific transcription factors and the precise role of phosphorylation in regulating cutinase gene transcription remain to be elucidated.