Mechanism by which contact with plant cuticle triggers cutinase gene expression in the spores of Fusarium solani f. sp. pisi

Journal Article · Sat Mar 01 04:00:00 EST 1986 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.83.6.1704· OSTI ID:5933930

Woloshuk, C P; Kolattukudy, P E

Spores of the phytopathogenic fungus Fusarium solani f. sp. pisi were shown to produce the extracellular enzyme, cutinase, only when cutin or cutin hydrolysate was added to the spore suspension. Dihydroxy-C/sub 16/ acid and trihydroxy-C/sub 18/ acid, which are unique cutin monomers, showed the greatest cutinase-inducing activity. Experiments with several compounds structurally related to these fatty acids suggested that both a omega-hydroxyl and a midchain hydroxyl are required for cutinase-inducing activity. Cutinase appeared in the medium 30-45 min after the addition of the inducers to the spore suspension, and the activity level increased for 6 hr. Addition of cycloheximide (5 ..mu..g/ml) completely inhibited cutinase production, suggesting that protein synthesis was involved in the increase of cutinase activity. Immunoblot analysis with rabbit antibodies prepared against cutinase showed that cutinase protein increased in parallel with the increase in enzyme activity. Measurement of cutinase-specific RNA levels by dot-blot hybridization with /sup 32/P-labeled cutinase cDNA showed that the cutinase gene transcripts could be detected within 15 min after addition of the inducers. Addition of exogenous cutinase greatly enhanced the level of cutinase gene transcripts induced by cutin. These results strongly suggest that the fungal spore senses that it is in contact with the plant by the production of small amounts of cutin monomers catalyzed by the low level of cutinase carried by the spore and that these monomers induce the synthesis of cutinase needed for penetration of the fungus into the plant.

• Research Organization: Washington State Univ., Pullman
• OSTI ID: 5933930
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 83:6; ISSN PNASA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL WALL
DAYS LIVING RADIOISOTOPES
DNA
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
ESTERS
FUNGI
FUSARIUM
GENE REGULATION
HYBRIDIZATION
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LYASES
MESSENGER-RNA
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PARASITES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PLANTS
POLYESTERS
POLYMERS
RADIOASSAY
RADIOISOTOPES
RECOMBINANT DNA
RNA
SPORES