Germination and Metabolism of Pinus radiata Pollen in the Presence of Sulfur Dioxide

Abstract

Summary Pinus radiata pollen grains produced in the geothermal regions of New Zealand are likely to be exposed to atmospheric SO 2 . Tests have been made to assess whether SO 2 adversely affects the germination of the pollen and whether exposure to the gas alters the early metabolism. Inhibition of germination was confirmed microscopically. The pollen grains were allowed to germinate in tritiated water after they had been exposed to a range (0.1–10.0 ppm) of sulfur dioxide concentrations and the 3 H-labelled metabolites were identified by chromatographic and autoradiographic techniques. The percentage activity incorporated into aspartic, γ-amino-butyric-, citric-, glutamic-, and malic-acids, alanine and glutamine generally decreased as the SO 2 concentration increased.