Lipids in the germ, endosperm and pericarp of the developing maize kernel

Abstract

Acyl lipids were quantified in the germ, endosperm and pericarp of LG‐11 maize kernels at eight stages of development from 9 to 87 days after pollination (DAP). Changes in the lipids are discussed in relation to morphological events in the developing kernel. Storage lipids (triglyceride, steryl ester) and membrane lipids (diacylphospholipids) accumulated in germ until 52–76 DAP, then decreased slightly without formation of lipid degradation products, lated in endosperm until 36–42 DAP and then decreased. Maximum values for galactosyldiglycerides and diacylphospholipids (nonstarch lipids) were reached at 16–23 DAP, and all decreased to very low values at maturity. Loss of these functional (membrane) lipids during the period of endosperm cell filling is unexpected. Starch contained 82% of the lysophospholipids and 64% of the free fatty acids in endosperm at 76 DAP. Endosperm lysophospholipids increased until 76 DAP and then decreased slightly, while free fatty acids increased continuously mostly inside starch granules at all stages of development, and any possible decrease after 76 DAP was masked by acids formed by hydrolysis of aleurone and endosperm nonstarch lipids from 52 DAP. In DAP, and phospholipids decreased after 42 DAP. Loss of these lipids is associated with senescence of most pericarp tissue. Triglycerides and steryl esters accumulated steadily to maturity, while the main accumulation of unsaponifiables occurred after 52 DAP about the time of suberin formation.

Lysophosphatidylcholine Identified as Channel‐Associated Phospholipid of Maize Starch Granules

“…As indicated in Fig. Tan and Morrison (1979b) found that the starch contained 82% of the lysophospholipids of maize endosperm. These components correspond to lysophosphatidylcholine (LPC) with palmitic acid (16:0) (Petković et al 2001) and linoleic acid (18:2) (Petković et al 2001(Petković et al , 2002, respectively, as the acyl group.…”

Expression of Fungal diacylglycerol acyltransferase2 Genes to Increase Kernel Oil in Maize

“…Although oil makes up only a small proportion of maize (Zea mays) grain (approximately 4%), maize oil is the second in volume vegetable oil produced in the United States, after soybean (Glycine max) oil (Ash and Dohlman, 2006). Maize kernel oil is composed primarily of triacylglycerol (TAG) and is used as an energy source by the plant during seed germination (Tan and Morrison, 1979). Most of the oil in a maize seed is found in the embryo, which is about 33% oil by weight (Watson, 1987).…”

Characterization of maize endosperm-derived suspension cells throughout the culture cycle and enhancement of tissue friability

“…The steady, if low, levels of these storage compounds in the cultures is indicative of the maintenance of a degree of differentiation as endosperm ceils. The cultures contain over ten times as much total lipid per mg dry weight as does intact endosperm tissue (Tan & Morrison 1979). The significance of this is unclear, due to the major contribution of starch to the dry weight of intact endosperm tissue.…”