Plant lipids sulfolipids

Glycolipids are important constituents of the plasma membranes, of the endoplasmic reticulum, and of chloroplasts. The cerebrosides and their sulfate esters, the sulfatides, are especially abundant in myelin. In plant membranes, the predominant lipids are the galactosyl diglycerides.29 74 The previously described ether phospholipids (archaebacteria), ceramide arnino-ethylphosphonate (invertebrates), and sulfolipid (chloroplasts) are also important membrane components. 

The photosynthetic membranes of higher plant chloroplasts have an unusual lipid composition 60 - 80 % galactolipids (MGDG, DGDG), approx. 10 % sulfolipid (SQDG), approx. 10 % (trans 16 3) phosphatidyl-glycerol (PG), 5 - 10 % phosphatidylcholines (PC) and hardly or no... 

Although most attention has been directed toward the analysis of leaves or storage tissues, data are available for other plant tissues such as roots and shoots. In general, the high linolenic acid content of leaves is replaced by linoleic acid in roots. In addition, phosphatidylcholine becomes relatively more abundant as the contribution toward total acyl lipids made by the chloroplastic galactosylglycerolipids, sulfolipid, and phosphatidylglyc-erol declines. A few representative papers are those by Body (1974), Cher-rad et al. (1974), Jarvis and Duncan (1974), and Sukhija et al., (1976). 

Bieleski (1972) compared phosphate-deficient S. oligorhiza (Kurz) He-gelm. and controls in phospholipid synthesis from Pi. The major labeled lipid in both cases was PC, but the phosphate-deficient culture showed greatly diminished labeling of PG and PI. Tevini (1971) has measured the effect of phosphate deficiency on phospholipid content in Impatiens balsa-mina and H. vulgare. While chlorophylls a and b, galactosyldiglycerides, and sulfolipid are normal in phosphorus-deficient plants, all phospholipids are 30 or 70% of the control in Impatiens and Horedeum, respectively. 

A characteristic fragment ion at mh 225 corresponding to a dehydrosulfoglyco-syl anion. (Thus, PIS of this ion in the negative-ion mode can be used to profile all sulfolipid species present in lipid extracts of plant samples as demonstrated previously [7]). 

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