Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Apoplast: a sensitive site for assessing some biochemical in Norway spruce needles. | 590s Ann. Sci. For. 1989 46 suppl. 59ŨS-594S Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Apoplast a sensitive site for assessing some biochemical effects of o3 or so2 in Norway spruce needles G. Ogier . Castillo and H. Greppin Laboratory of Plant Biochemistry and Physiology University of Geneva CH-1211 Geneva 4 Switzerland Introduction The study of the cell wall-plasma membrane interphase is of great importance for the understanding of gaseous air pollutants and leaf cell interactions. In the apo-plast liquid phase the pollutants are solubilized and they can generate oxidative products Tingey and Taylor 1982 . For example 03 or so2 could lead to H2O2 production Tingey and Taylor 1982 Khan and Malhotra 1982 . In order to protect the plasma membrane and the components of the extracellular matrix cells are believed to dispose of oxidant-scavenging mechanisms. One of the enzymatic systems which could play a protective role against oxidative stresses includes peroxidases Castillo and Greppin 1988 . Peroxidase activity with guaiacol as the electron donor and protein content were measured in Norway spruce needles Picea abies L. Karst after fumigation 24 h d in semi-open top chambers for 12 wk in summer with 03 or for 10 wk in winter with so2. These parameters were followed in the intercellular washing fluid IWF and in the residual cell material RCM . The plants treated in summer remained 12 wk longer in the chambers in order to assess any visible injury caused by 03 in autumn. Materials and Methods Two groups of 20 clone saplings 4 yr old grafted p. abies were selected from the nursery of the Swiss Federal Institute of Forestry Research Birmensdorf CH one group for each experiment. Prior to fumigation the plants were distributed randomly into 4 semi-open top chambers 5 individuals per chamber . Current year old needles and 1 yr old needles were analyzed in samples harvested at the end of the fumigation period The experimental approach is shown in Table .