Changes in the phospholipid molecular species composition of soybean hypocotyl and cotyledon after dedifferentiation

The effect of dedifferentiation on the molecular species composition of soybean phospholipids was studied by using hypocotyl, cotyledon and the suspension culture cells established from those organs. Three major phospholipids (phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol) and phosphatidylmonomethylethanolamine were composed of twelve molecular species. Major species were 1-palmitoyl-2-linoleoyl, 1-obeoyl-2-linoleoyl, 1-palmitoyl-2-linolenoyl and 1-linoleoyl-2-linoleoyl species. Different proportions of the molecular species were found among the three major phospholipids, but phosphatidylmonomethylethanolamine was composed of the same proportions of the molecular species as those of phosphatidylethanolamine. After dedifferentiation, the 1-palmitoyl-2-linoleoyl species increased in the cell established from hypocotyl. In the cells established from cotyledon, the 1-palmitoyl-2-linolenoyl species increased dramatically. In both cells, the 1-palmitoyl-2-linolenoyl species increased in response to increase in the 2,4-dichlorophenoxyacetic acid concentrations and the progress of cell growth.