Total Fatty Acid and Polar Lipid Content in Developing Flower of Nicotiana tabacum

Flower organs of Nicotiana tabacum had lower ratios of linolenicacid than the leaf at all stages of development. The petal,ovary and anther (before anthesis) had linoleic acid as themajor fatty acid, and the pistil had high amounts of oleic acid.As for polar lipids, flower organs generally had lower proportionsof chloroplast lipids than the leaf, which resulted in a highproportion of phospholipids such as phosphatidylcholine, phosphatidylinositoland phosphatidylethanolamine. The fatty acid compositions ofthese phospholipids did not change significantly between theearly bud stage and the fully opened flower stage, whereas thoseof monogalactosyldiglyceride and digalactosyldiglyceride changedsignificantly. The oleic acid-rich substances in the pistilwere not detected in the polar lipid regions. Hexadecenoic andhexadecatrienoic acids, which are characteristic of the phosphatidylglyceroland monogalactosyldiglyceride, respectively, in the leaf, weredetected in small amounts in the petal, but not in other flowerorgans. (Received September 16, 1982; Accepted December 20, 1982)