Respiration, C2H4 production, lipid composition, and electrolyte leakage were monitored during ripening of two nonnetted muskmelon (Cucumis melo L.) varieties differing in their storage life: `Clipper' (a long-storage-life variety) and `Jerac', which was used as a control. Respiration rates were comparable in both varieties. Although `Jerac' exhibited normal climacteric C2H4 production, `Clipper' continued to produce significant amounts of C2H4 until senescence. Electrolyte leakage increased with ripening and was always higher in `Jerac'. The loss of membrane integrity seems to be related to changes in the lipid composition due to a breakdown of phospholipids, an increase of sterol synthesis, and an increase in fatty acid saturation. On the contrary, in `Clipper', the absence of a major change in sterol and phospholipids content and the high level of fatty acid unsaturation suggest that membrane permeability is not greatly affected during ripening. This is consistent with the low loss of solutes measured and may delay senescence in `Clipper' fruit.
the lipid bilayer shifts from a liquid crystalline state to gel crystalline state ( Raison and Orr, 1990 ). This solidification of membrane lipids at low temperature is followed by contraction and the formation of cracks ( Lyons and Raison, 1970
membranes and chloroplast membranes may form a hexagonal II phase (H II ), which compromises membrane integrity and cell function ( Cullis and De Kruijff, 1979 ; Uemura and Steponkus, 1997 , 1999 ). Thus, during cold acclimation, changes in lipid
histochemical changes associated with the various developmental stages of anthers were investigated, with a focus on changes of polysaccharides and lipids, which are nutritional materials. Study on the synthesis and distribution of nutritional constituents in
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
Mojtaba Massoudi is gratefully acknowledged for his technical assistance in lipid analysis. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby
lipid bilayers with associated and embedded proteins, have long been proposed as one of the prime sites of vulnerability or tolerance to heat and cold stress in plants ( Armond et al., 1980 ; Quinn, 1988 ; Vigh et al., 1993 ). The composition of lipid
Abbreviations: ASG, acylated steryl glycoside; DGDG, digalactosyldiacylglycerol; FS, free sterols; GL, galactolipids; GlyL, glycolipid; MGDG, monoga-lactosyldiacylglycerol; NL, neutral lipid; PA, phosphatidic acid; PC, phosphatidylcholine; PE
active oxygen species (AOS) such as singlet oxygen ( 1 O 2 ), superoxide (O 2 .− ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radicals (OH·) ( Asada, 1999 ). These species can cause oxidative damage to lipids, nucleic acids, and proteins ( Smirnoff
to $41 million in 2009 ( Bernick, 2009 ; Soyatech, 2010 ). Agronomic soybeans have high lipid content and are commonly used as an industrial source of oil. However, high oil content gives edamame an undesirable flavor ( Konovsky et al., 1994