Báo cáo lâm nghiệp: Assessment of the contributions of glycolysis and the pentose phosphate pathway to glucose respiration in ectomycorrhizas and non-mycorrhizal roots of spruce (Picea abies L. Karsten)

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Assessment of the contributions of glycolysis and the pentose phosphate pathway to glucose respiration in ectomycorrhizas and non-mycorrhizal roots of spruce (Picea abies L. Karsten)...
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Báo cáo lâm nghiệp: " Assessment of the contributions of glycolysis and the pentose phosphate pathway to glucose respiration in ectomycorrhizas and non-mycorrhizal roots of spruce (Picea abies L. Karsten)"Assessment of the contributions of glycolysisand the pentose phosphate pathway to glucoserespiration in ectomycorrhizas and non-mycorrhizalroots of spruce (Picea abies L. Karsten) V. Guillot, F. Martin F. Le TaconI. Bilger,Laboratoire de Microbiologie Forestiere, Centre de Recherches Forestieres de Nancy, InstitutNational de la Recherche Agronomique, Champenoux 54280 Seichamps, France roots. The substrate used well as theIntroduction as in this pro- pathways potentially involved not known. cess are importance of carbon supply inThe The aim of this study was to determinemycorrhizal infection and symbiotic activity the relative contribution of glycolysis andhas long been recognized. The supply of the pentose phosphate pathway to glu-carbohydrates by the higher plant to the oxidation in Norway (Picea cose sprucefungus is a very basic trait of mycorrhizal abies) ectomycorrhizas.symbiosis. Mycorrhizal plants assimilatemore photosynthates than non-mycorrhi-zal ones, allocate a greater fraction of theassimilated carbon to the root systems Materials and Methodsand lose a greater fraction of the assimi-lated carbon to respiratory C0 than do 2non-mycorrhizal plants (for a review, see Plant materialMartin et al., 1987). The establishment of Four year old plants of Picea abies L. Karsten,a carbon sink by the ectomycorrhizal grown on a sandy soil, were sampled fromhyphae may be attained by: 1 ) rapid car- a commercial bare-roots nursery (Merten,bohydrate degradation for respiration and Vosges, eastern France). The plants were removed with attached soii, stored at 4°C andfor energy and reducing power production transferred to the laboratory. The root systemsand 2) conversion of plant carbohydrates were washed with tap water and all soil par-into fungal biomass. The high respiration ticles were removed. The pyramidally branchedrate of fungal tissues has been pointed out ectomycorrhizas were pale brown, racemose with a prosenchymatous sheath, a thin mantleby several authors (France and Reid, and an extensive Hartig net reaching to the1983). Most studies of mycorrhizal respi- endodermis. There abundant extramatric- wereration deal with mitochondrial respiration. mycelia (Hebeloma sp.) interconnected with alMuch less is known about the oxidative loosely woven, pale yellow mycelial cords (seemetabolism of glucose in mycorrhizal Fig. 1 in Al-Abras et al.. 1988; Dell et al., 1989).Assuming that the same chitin/protein ratio streptomycin and 0.008% (w/v) aureomycin. Soluble compounds were then extracted ac- in the mycelial cords of Hebeloma sp.occurs cording to A[-Abras et aL (1988) and radio-and the fungal component of the ectomycorrhi-zas, then approximately 50% of the protein in activity determined by counting 100 ul aliquots. Chitin was determined by measuring thethe ectomycorrhizas is fungal (Dell et al., 1989). amount of fungal glucosamine resulting from hydrolysis of chitin in mycorrhizal roots and ...