Pathogenesis-Related Proteins in Scots Pine Seedlings Inoculated with Gremmeniella abietina : Shoot and Foliage Diseases in Forest Trees. Proceedings of a Joint Meeting of the Working Parties Canker and Shoot Blight of Conifers (S2.06.02) Foliage Diseases (S2.06.04)

Florenz

1995

S. 162-165

13 Lit. Ang.

Bandaufführung

77404

The accumulation of PR proteins (pathogenesis-related proteins) under various biotic and abiotic stresses has been observed in a number of plants. In conifers this kind of response to microbial infection has been detected only in root systems. The induction of PR proteins in spruce needles following exposure to ozone has also been reported. The aim of the present work was to study host-pathogen interaction at the molecular level in current-year needles of Scots pine seedlings. Gremmeniella abietina (Lagerb.) Morelet was chosen as the infecting agent because of its widespread occurrence in Finnish Lapland in the 1980 's especially. Two different pine provenances were planted outdoors in pots or directly into the ground at Rovaniemi, Finland. Half of the three-year-old seedlings were infected artificially with Gremmeniella abietina. Needle samples were taken for protein analysis by the Western blot mehtod with maize anti-PRm 6 and tobacco anti-PR-P antibodies. A minor, natural Gremmeniella abietina infection (1.9% of seedlings) occurred in the experiment area prior to artificial inoculation. After inoculation 12.4% of all the seedlings became infected. The number of successful infections was highest (20.5%) in the group of ground-planted, inoculated seedlings. Only one third of a random sample of seedlings proved to be infected, and only one half of them with Gremmeniella abietina. The Western blot analysis was not very successful in demonstrating the effect of this pathogen on the induction of PR proteins in pine needles in the field, but it does appear to be a useful molecular biological technique in more strictly controlled experiments.