differ with plant species. One characteristic of anther development is the accumulation of nutrients, generally polysaccharides or neutral lipids, in the pollen pool to fuel the subsequent pollen ontogeny, germination on the stigma surface, and growth of
Seven mutant maize genotypes with sweet corn backgrounds and 4 commercially grown sweet corn cultivars were harvested from 18-45 days after pollination (DAP). The lipids were extracted with chloroform-methanol 2: 1 (v/v) and separated on a silicic acid column into neutral lipids, glycolipids and phospholipids. Mutant genotypes influenced lipid development while inbred lines seemed important in amount of oil synthesized by the kernel. Crude oil and neutral lipids increased from 18-45 DAP while phospholipid and glycolipid values (mg/10 g fresh weight basis) were higher 23-28 DAP which is the prime processing time. During the developmental period studied, neutral lipids, phospholipids and glycolipids amount to 63, 20, and 12% respectively of the crude oil extracted. About 5% of the crude oil was lost in the separation procedure.
analogues where basic fuchsin combines to display red color ( Dahlqvist et al., 1965 ). These sections were then counter-stained with 0.3% (w/v) Sudan Black B (19966-4; Sigma-Aldrich) for 30 min at 60 °C to detect neutral lipid droplets. The Sudan Black B
Effects of different plant oils (soybean oil, corn oil, olive oil, peanut oil, linseed oil, and cotton seed oil) and oil component emulsions on scald development in `Delicious' apples were studied. Prestorage treatment with commercial plant oils reduced scald development, but was not as effective as 2000 mg•L-1 diphenylamine (DPA) after 6 months of cold storage. Different oil components played different roles in affecting scald. At 6% or 9% concentrations, neutral lipids (mono-, di-, and tri-acylglycerols), and phospholipids inhibited scald to the same level of 2000 mg•L-1 DPA treatment. Free fatty acids partially reduced scald, while α-tocopherol at 3% or higher concentrations accelerated scald development. There were no differences in scald inhibition between unsaturated neutral lipids and saturated neutral lipids or among the different acylated neutral lipids. When α-tocopherol was stripped from plant oils, the stripped plant oils at 6% or 9% controlled scald to the same level of 2000 mg•L-1 DPA treatment. Emulsions of 6% or 9% neutral lipids, phospholipids, or stripped plant oils did not induce greasiness on fruit skin. Fruit treated with lipids, phospholipids, or stripped plant oils looked greener and fresher compared with the control by the end of storage.
The study evaluated the roles of storage carbohydrates and neutral lipids in the success of Colorado blue spruce (Picea pungens Englemann ‘Hoopsi’) grafts. These scions do not require photosynthesis nor receive photosynthates from the rootstock during union development. Carbohydrate and neutral lipid contents, along with respiration and scion water relations, were measured during union development. Stored carbon compounds were sufficient to supply the needs of the scion during the 9 weeks of union development. Estimates of carbohydrate use indicated that decreases in sugar content (bark and needle) were insufficient to account for more than 25% of the estimated respiration. The results indicate that the quantity of carbon storage compounds is not a factor in graft success. We propose that neutral lipids may be the major carbon reserve of the scion during graft formation.
Major leaf alkanes (C29-C33) of 2 scions on 10 rootstocks of citrus were examined by gas chromatography. A small but definite effect of the rootstock on the alkane profiles of the scions was observed. The effect of rootstock on alkane patterns in juice sacs was very small. Rootstock affected the fatty acid patterns of total and neutral lipids as well as of triglycerides and sterol esters.
Abbreviations: DTT, dithiothreitol; FAME, fatty acid methyl ester, NL, neutral lipids; PL, polar lipids; PVPP, polyvinylpolypyrrolidone. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations
Seven mutant maize genotypes with sweet corn backgrounds and 4 commercially grown sweet com cultivars were harvested from 18-45 days after pollination (DAP). The lipids were extracted, separated into major lipid fractions, transesterified and measured as methyl esters of palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2) and linolenic (18:3) acids by gas liquid chromatography (GLC). Neutral lipids had a low ratio of polyunsaturates to monounsaturates (1.7:1), i.e., linoleic and linolenic to oleic fatty acids. Glycolipids had the highest proportion of linoleic and linolenic acids. Phospholipids tended to be more saturated than other fractions because of their high proportion of palmitic acid. All fatty acids in the neutral lipid fraction increased on an absolute basis with advancing maturity. Fatty acids in the glycolipid and phospholipid fractions generally peaked at 28 DAP on a mg fatty acid/g corn wet weight basis and then decreased with increased maturity. The percentage of oleic acid in the glycolipid fraction doubled from 12-24 percent during the 18-45 DAP period. Experimental lines and commercial cultivars contained 18.4, 1.4, 21.5, 57.1 and 2.1 percent respectively of palmitic, stearic, oleic, linoleic and linolenic acid over the maturity ranges studied.
Cashew (Anacardium occidentale L.) nut neutral lipids, glycolipids and phospholipids were isolated by silicic acid column chromatography. Each lipid class had characteristic fatty acid distributions with phospholipids being higher in palmitic and oleic acids, and glycolipids being higher in lin oleic acid. Comparative esterification methods indicated that cashew apple juice contained significant amounts of free lauric acid. Oleic and linoleic acids occur in almost identical, amounts in cashew nut testa whereas oleic acid predominates in the kernel. Comparison of fatty acid distributions in pulp and peel from red and yellow cultivars of cashew apple at immature and mature stages shows some differences, with notable increases in oleic acid during maturation and decreases in linoleic and linolenic acids.
Altered metabolism of membrane lipids has been proposed as a mechanism for the beneficial effects of postharvest calcium treatment on apple quality. A previous study showed that after transfer of apples stored 6 months at 0C to 20C, calcium-treated fruit exhibited slower loss of galactolipid and altered levels of sterol conjugates. The present study of lipids in “control” fruit was conducted as a prelude to further in-depth analyses of the effects of postharvest calcium and heat treatments on lipid metabolism in apples during and after cold storage. Neutral lipid, glycolipid (GL), and phospholipid (PL) fractions were obtained by column chromatography followed by TLC separation of GL and PL classes. The major GL were steryl glycosides (SG), acylated steryl glycosides (ASG), cerebrosides (CB), and mono- and digalactosyl diacylglycerols. Phosphatidylcholine (PC) > P-ethanolamine (PE) > P-irositol (PI) were the major PL. The fatty acids of PC and PE were quite similar, whereas those of PI were more saturated. CB included only 2-hydroxy fatty acids. Among the steryl lipids, free sterols > SG > ASG, with beta-sitosterol >90% of the total sterol in each.