Article

Inhibition of plant-pathogenic fungi by a corn trypsin inhibitor overexpressed in Escherichia coli.

Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA.
Applied and Environmental Microbiology (impact factor: 3.83). 04/1999; 65(3):1320-4. pp.1320-4
Source: PubMed

ABSTRACT The cDNA of a 14-kDa trypsin inhibitor (TI) from corn was subcloned into an Escherichia coli overexpression vector. The overexpressed TI was purified based on its insolubility in urea and then refolded into the active form in vitro. This recombinant TI inhibited both conidium germination and hyphal growth of all nine plant pathogenic fungi studied, including Aspergillus flavus, Aspergillus parasiticus, and Fusarium moniliforme. The calculated 50% inhibitory concentration of TI for conidium germination ranged from 70 to more than 300 microgram/ml, and that for fungal growth ranged from 33 to 124 microgram/ml depending on the fungal species. It also inhibited A. flavus and F. moniliforme simultaneously when they were tested together. The results suggest that the corn 14-kDa TI may function in host resistance against a variety of fungal pathogens of crops.

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Keywords

14-kDa trypsin inhibitor
 
active form
 
Aspergillus flavus
 
Aspergillus parasiticus
 
calculated 50% inhibitory concentration
 
cDNA
 
conidium germination
 
Escherichia coli overexpression vector
 
F. moniliforme
 
Fusarium moniliforme
 
host resistance
 
insolubility
 
nine plant pathogenic fungi
 
overexpressed TI
 
refolded
 
urea
 
vitro
 

Z-Y Chen