Molecular Plant-Microbe Interactions (2000) 13, 43-53
G. Del Sorbo, F. Scala, G. Parrella, M. Lorito, C. Comparini and M. Ruocco (2000)
Functional expression of the gene cu, encoding the phytotoxic hydrophobin cerato-ulmin, enables Ophiostoma quercus, a nonpathogen on elm, to cause symptoms of Dutch elm disease
Molecular Plant-Microbe Interactions 13 (1), 43-53
Abstract: We studied the involvement of the phytotoxic hydrophobin cerato-ulmin (CU) in pathogenesis and virulence of Dutch elm disease (DED) by expressing its encoding gene (cu) in Ophiostoma quercus, a nonpathogenic species on elm closely related to the DED pathogens O. ulmi and O. novo-ulmi. The production of the toxin was quantitatively determined in culture filtrates and in mycelial extracts of the transformants. Production of CU in vitro was associated with the ability to cause typical DED symptoms, consisting of foliar yellow and wilting and vascular tissue discoloration on a moderately resistant elm genotype. The presence of CU was monitored by enzyme-linked immunosorbent assay in symptomatic leaves of plants inoculated with O. quercus transformants expressing CU and found to be associated with wilt symptoms. In general, the virulence of the cu-expressing transformants, as measured in terms of vascular discoloration and percentage of defoliation, was lower than that of the mildly pathogenic isolate E2 of O. ulmi. However, one transformant (C39) displayed a virulence level intermediate between that of E2 and 182, a highly virulent isolate of O. novo-ulmi. Our results indicate that CU production influences virulence in nonaggressive strains of Ophiostoma fungi.
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Link to article at publishers website
Database assignments for author(s): Giuseppe Parrella, Felice Scala
Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
molecular biology - genes
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Ophiostoma ulmi | ||||
| Ophiostoma novo-ulmi | ||||
| Ophiostoma quercus |
