Lipidomics studies reveal dynamic changes in polar lipids of developing endosperm of oat and wheat varieties with differing oil contents.

ABSTRACT

Polar lipids have biosynthetic pathways which intersect and overlap with triacylglycerol biosynthesis; however, polar lipids have not been well characterized in the developing endosperms of oat with high oil accumulation. The polar lipids in endosperms of oat and wheat varieties having different oil contents were analyzed and compared at different developmental stages. Our study shows that the relative contents of polar lipid by mass were decreased more slowly in wheat than in oat. Phosphatidylcholine and phosphatidylethanolamine were the major phospholipids, which showed similar abundance and gradual decreases during endosperm development in oat and wheat, while lysophospholipids were noticeably higher in oat. Monogalactosyldiacylglycerol showed a gradual increase in wheat and a decrease in oat during endosperm development. The relative contents of some polar lipid species and their unsaturation index were significantly different in their endosperms. These characteristics of polar lipids might indicate an adaption of oat to accommodate oil accumulation.