Poster: Oxidative stress

Abs # 74: South-to-north transplantation induces changes in soluble and oxidatively modified proteins in Scots pine seedlings

Presenter:	Taulavuori, Erja , erja.taulavuori@oulu.fi
Authors	Taulavuori, Erja  (A)   Taulavuori, Kari  (A)   Tahkokorpi, Marjaana  (A)   Laine, Kari  (A)
Affiliations:	(A): University of Oulu, Department of biology

The predicted doubling of the current atmospheric carbon dioxide concentration (370 ppm) by the end of this century will lead to climatic warming by up to 7 degrees Celsius in the northern boreal zone, which may enable plants to migrate towards the north. To study the effects of south-to-north transplantation, one-year-old Scots pine (Pinus sylvestris ) seedlings of the provenances of Kuhmo (64 degrees N) and Ranua (66 degrees N), Northern Finland (Europe), were transplanted in 1997 0, 1, 2 and 3 degrees N higher than the latitude of origin. Sampling was carried out twice per year during 1998-2000, i.e. in May before the onset of growth and in September at the autumnal equinox. Soluble and oxidatively modified protein profiles in the youngest needles were identified by SDS-PAGE and Western blotting. The intensities of the proteins decreased towards the north in the provenance of Kuhmo, while in the provenance of Ranua they slightly increased northward. Oxidation of proteins, as indicated by the number of carbonyl groups, increased towards the north in the provenance of Kuhmo, while no trend was seen in the provenance of Ranua. The results suggest that the Kuhmo provenance had experienced more severe oxidative stress due to the transplantation compared to the Ranua provenance. The lowest protein concentrations were found in 1998 and the highest oxidation of proteins in spring in the same year, suggesting that the most severe stress occurred during the first year. The oxidation of proteins was more pronounced in spring than in autumn throughout the whole experiment, which may be indicative of photo-oxidative stress during the spring.