Phenol-water extraction of Rhizobium loti NZP2213 cells allowed a simultaneous isolation of two structurally different lipopolysaccharides from the aqueous (LPS-W) and phenol (LPS-P) phase that differed in their sodium deoxycholate-PAGE pattern and composition. LPS-W showed a profile indicating an R-type LPS; LPS-P had a cluster of poorly resolved bands in the high-molecular-weight region. LPS-P contained large amounts of 6-deoxy-L-talose (6dTal), and a small amount of 2-O-methyl-6-deoxy-talose (molar ratio approximately 30:1), both of which were completely absent in LPS-W. Methylation analysis gave only one major product, 2,4-di-O-methyl-6dTal, indicating that the O-chain is composed of a homopolymer of 1,3-linked 6dTal, having the methylated 6dTal (2-O-Me-6dTal) probably localized at the non-reducing end of the O-chain. This homopolymeric O-chain was additionally O-acetylated, as evidenced by GC-MS and by 13C NMR analysis. The lipid A moieties of both LPS-W and LPS-P showed almost identical composition, with six different 3-OH fatty acids and with two, so far not described, long-chain 4-oxo-fatty acids, all being amide-linked, and with 27-OH-28:0 as the main ester-linked fatty acid. Lipid A was of the lipid ADAG-type, i.e., having a (phosphorylated) 2,3-diamino-2,3-dideoxy-D-glucose-containing lipid A backbone. Lipid ADAG is widespread among species of the alpha-2 group of Proteobacteria, but has so far not been encountered in any other rhizobial or agrobacterial species.

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Runner bean plants (Phaseolus coccineus L., cv Piekny Jas) were treated with excess Cu (20 mg l−1 in the form of CuSO4.5H2O) at different stages of growth to investigate, 10 days after the element treatment, the effect of Cu on acyl lipid and polypeptide composition of the thylakoid membranes and their PSII photochemistry. The plants treated with Cu in the initial stage of leaf growth showed a strong reduction in the area and fresh weight of the primary leaves. The concentration of chlorophyll and acyl lipids slightly increased when calculated on leaf area or fresh weight basis. The decrease in individual acyl lipid classes expressed on chlorophyll basis was accompanied by lower accumulation of some extrinsic polypeptides of the oxygen evolving complex and decrease in PSll activity (80% of control). Chlorophyll a fluorescence measurements suggest an inhibitory effect of Cu on the acceptor side of PSII due to induced inhibition of the Calvin cycle and down‐regulation of electron transport. However, plants treated with Cu by the end of the intensive growth stage of the primary leaves showed chlorosis and almost unchanged leaf area. Moreover, significant changes in acyl lipid content as well as a distinct loss of core antenna PSII polypeptides and oxygen evolving complex subunits were observed. Changes in chlorophyll a fluorescence parameters of the thylakoid membranes suggest that low PSII activity (50% of control) may result from an alteration both in the acceptor and donor sides of PSII and its reaction centre. The growth stage of plants in which Cu was applied to plants and the duration of Cu action appears to be of great importance for the interpretation of experimental data.

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