Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » Cereal Crops Research » Research » Publications at this Location » Publication #102672
Title: CHANGES IN ALKALINE OF FUSARIUM-INFECTED BARLEY DURING KERNEL DEVELOPMENT

Author
item PEKKARINEN, ANJA - VTT, UNIV. HELSINKI, FNLD
item SARLIN, TUIJA - VTT, UNIV. HELSINKI, FNLD
item LAITILA, ARJA - VTT, UNIV. HELSINKI, FLND
item NIKU-PAAVOLA, MARJA-LEENA - VTT, UNIV. HELSINKI, FLND
item Jones, Berne

Submitted to: Barley Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Fusarium spp. attack cereal plants, reducing crop yields and quality. Among other things, they use up the storage reserves of the grain, reduce the seed germinability and seedling vigour, and often produce mycotoxins. The fungi probably use enzymes for penetrating the host cell walls and for hydrolyzing their proteins, carbohydrates and lipids. Earlier, we showed that Fusarium culmorum, F. graminearum and F. poae all produced an alkaline, chymotrypsin-like proteinase when they were grown on media that contained either gluten or barley grain. In this study, we have investigated whether this proteinase was produced in developing barley kernels. Barley (Hordeum vulgare L. cv. Saana) spikes were inoculated with spores of the Fusarium species listed above at anthesis in two fields in southern Finland and kernel samples were collected every 2-3 weeks until harvest. The chymotrypsin-like activities of grain extracts were measured using the synthetic substrate N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide. The activities of the F. culmorum and F. graminearum extracts increased strongly during development, reaching a maximum 5-6 weeks after inoculation. However, those of F. poae increased only slightly. This shows that the chymotrypsin-like proteinase is produced in developing barley kernels that have been infected by the most pathogenic Fusarium species, implying that the chymotrypsin-like proteinase may help the fungi to thrive in the kernel. We have purified the proteinase from F. culmorum and have demonstrated that some component of barley grains inhibits its activity. Studies will be carried out to determine whether this proteinase inhibitor is also able to inhibit the growth of the Fusarium species in vitro.