Seed storage lipid

It has, thus, been demonstrated that redirecting the poly(3HB) biosynthetic pathway from the cytoplasm to the plastid resulted in an approximate 100-fold increase in poly(3HB) production [24]. However, it must be kept in mind that the rate of poly(3HB) biosynthesis in A thaliana leaves was relatively low, since poly(3HB) accumulated progressively over 40-60 days to reach 10-14% of the dry weight, whereas synthesis of starch can reach 17% dry weight for a 12 h photoperiod and seed storage lipids can reach 8% dry weight per day. 

Voelker, T, Kinney, A.J. 2001. Variations in the biosynthesis of seed-storage lipids. Anna. Rev. Plant Physiol. Plant Mol. Biol. 52 335-361. 

James, Jr., D.W. and Dooner, H.K. (1989) Arabidopsis plants with altered seed storage lipids obtained by chemical mutagenesis-isolation of genes via transposon tagging. J. Am. Oil Chem. Soc. 66, 466. 

Lipids are essential plant components as they are constituents of membranes and cuticular waxes as well as being major seed storage... 

Many lipids are essential to good human health. Some of them serve as chemical messengers in the body. Others serve as ways to store chemical energy. There is a good reason that babies are born with baby fat. Seeds contain lipids for the storage of energy. People living in Arctic zones seek fatty foods in their diet. 

Vereshchagin, AG. Biochemistry of triglycerides. M Nauka, 1972, 1-308. (In Russian) Graham, I. Seed storage oil mobilization. Annu. Rev. Plant Biol, 2008, 59,115-142. Berezhnaya, GA Ozerinina, OV Yeliseev, IP Tsydendambaev, VD Vereshchagin, AG. Developmental changes in the absolute content and fatty acid composition of acyl lipids of sea buckthorn fruits. Plant Physiol, Biochem., 1993, 31, 323-332. 

The main sources of plant lipids of significance in diets are the leaves, which primarily provide a source of fatty acids for grazing animals and seed oils, which play a large role in human diets and an increasing one in farm animal diets. These are representative of the structural and storage lipids respectively and differ widely in fat composition (Sections 3.3 and 3.10). 

A lipase with an alkaline (pH 7.5) optimum has been identified in seeds of Vernonia anthelmintica, an oil seed in which a major storage lipid is triver-nolin (tri-12,13-epoxyoleoylglycerol). The partially purified enzyme has a high MW and can attack both primary and secondary ester bonds in the glyc-erolipid and does not distinguish between saturated and unsaturated fatty acids (Olney et [Pg.90]

Scheme 2 Cascade of events implicated in the linoleate 13>lipoxygenase-triggered mobilization of storage lipids in germinating seeds (according to the hypothesis of Feussner et al. [63]) ...

An accumulation of esterified hydro(pero)xy-polyenoic fatty acids in the storage lipids during germination has also been observed with some other oil-seeds (soybean, sunflower, anise, tobacco and rape [62,64]). Soybean seeds differ from the others in that lipoxygenase-derived oxygenated fatty acids are already present in the dry seeds [62]. 

Plant lipids are of two main types structural and storage. The structiu lipids are present as constituents of various membranes and protective surface layers and make up about 7 per cent of the leaves of higher plants. The surface lipids are mainly waxes, with relatively minor contributions from long-chain hydrocarbons, fatty acids and cutin. The membrane lipids, present in mitochondria, the endoplasmic reticulmn and the plasma membranes, are mainly glycolipids (40-50 per cent) and phosphoglyc-erides. Plant storage lipids occur in fruits and seeds and are, predominantly, triacyl-glycerols. Over 300 different fatty acids have been isolated from plant tissues, but only about seven are of common occurrence. The most abundant is a-linolenic acid the most common saturated acid is palmitic acid and the most common monounsaturated acid is oleic acid. 

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