Betaine lipids and zwitterionic phospholipids in plants and fungi

Of spermatophytes, ferns, mosses, algae, lichens and fungi, 110 species not analysed so far were examined for diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), diaclyglycerylhydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by TLC by using Dragendorff's and molybdenum-blue reagents for detection. The limit of detection was 0.5 microgram per mg or 0.05 weight % of total lipid. The results reveal that betaine lipids are present exclusively in non-flowering plants, including lichens and fungi and, hence, are produced by autotrophic, as well as heterotrophic organisms. DGTS in small amounts is typical of some Rhodophytes, and in appreciable amounts, of vascular cryptogamic plants and some higher fungi. Estimation of the amounts of DGTS and PC in 29 different species reveal that the total amount of zwitterionic lipids varies considerably amongst organisms. No general correlation could be found for the amounts of DGTS and PC, although Rhodophytes contain traces of DGTS but high amounts of PC. On the basis of these results and the presently available data, the natural distribution of the betaine lipids DGTS, DGTA and diacylglycerylcarboxy-N-hydroxymethyl-choline (DGCC) is discussed. In terms of biochemical evolution, the capacity for the formation of DGTS might have been acquired first and, in organisms of the 'DGTS branch', kept until the present time. The formation of DGTA and DGCC might have evolved at a later stage of development in organisms of the 'DGTA-DGCC branch'.