Change in lipid composition of wheat roots on early phase of mechanical stress

Changes of composition of phospholipid fatty acids, free fatty acids and phospholipids including lysophosphatidylcholine in the early stage (until one hour) of mechanical stress of wheat roots were studied. The saturation degree of phospholipid fatty acids sharply increases at expense of the decrease in the content of linoleic and linolenic acids within fifteen minutes after excision of roots from seedlings At the same time the increase of free fatty acids, lysophosphatidylcholine and the decrease of phospholipids were observed. This suggests that the action of phospholipases, in particular phospholipase A2, takes place in early phase of stress of wheat roots. It has been shown that alteration of lipid content in roots after excision depends on membrane fluidity and permeability for ions. It is suggested that early changes in lipid composition of wheat roots after excision may be considered as a response reaction of cells to mechanical stress and can be caused by the action of lipases in particular PLA2. This reaction is probably the unspecified one and is dictated by plasma membrane properties (fluidity, permeability).