EurekaMag.com logo
+ Translate

Regulation of Sterol Content in Membranes by Subcellular Compartmentation of Steryl-Esters Accumulating in a Sterol-Overproducing Tobacco Mutant


, : Regulation of Sterol Content in Membranes by Subcellular Compartmentation of Steryl-Esters Accumulating in a Sterol-Overproducing Tobacco Mutant. Plant Physiology 105(2): 509-518

The study of sterol overproduction in tissues of LAB 1-4 mutant tobacco (Nicotiana tabacum L. cv Xanthi) (P. Maillot-vernier, H. Schaller, P. Benveniste, G. Belliard [1989] Biochem Biophys Res Commun 165: 125-130) over several generations showed that the overproduction phenotype is stable in calli, with a 10-fold stimulation of sterol content when compared with wild-type calli. However, leaves of LAB 1-4 plants obtained after two steps of self-fertilization were characterized by a mere 3-fold stimulation, whereas calli obtained from these plants retained a typical sterol-overproducing mutant phenotype (i.e. a 10-fold increase of sterol content). These results suggest that the expression of the LAB 1-4 phenotype is dependent on the differentiation state of cells. Most of the sterols accumulating in the mutant tissues were present as steryl-esters, which were minor species in wild-type tissues. Subcellular fractionation showed that in both mutant and wild-type tissues, free sterols were associated mainly with microsomal membranes. in contrast, the bulk of steryl-esters present in mutant tissues was found in the soluble fraction of cells. Numerous lipid droplets were detected in the hyaloplasm of LAB 1-4 cells by cytochemical and cytological techniques. After isolation, these lipid granules were shown to contain steryl-esters. These results show that the overproduced sterols of mutant tissues accumulate as steryl-esters in hyaloplasmic bodies. The esterification process thus allows regulation of the amount of free sterols in membranes by subcellular compartmentation.

(PDF same-day service: $19.90)

Accession: 002477270

PMID: 12232218

DOI: 10.2307/4275867

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Atallah, A.M.; Nicholas, H.J., 1974: Function of steryl esters in plants: a hypothesis that liquid crystalline properties of some steryl esters may be significant in plant sterol metabolism. Lipids 9(8): 613-622

Bouvier Nave, P.; Benveniste, P., 1995: Sterol acyl transferase and steryl ester hydrolase activities in a tobacco mutant which overproduces sterols. The tobacco mutant LAB 1-4 overproduces sterols, most of which are esterified and stored as lipid droplets in the cytoplasm (P. Maillot-Vernier, L. Gondet, H. Schaller, P. Benveniste and G. Belliard, Mol. Gen. Genet. 231 (1991) 33-40). We studied...

Silvestro, D.; Andersen, T.Grube.; Schaller, H.; Jensen, P.Erik., 2013: Plant sterol metabolism. Δ(7)-Sterol-C5-desaturase (STE1/DWARF7), Δ(5,7)-sterol-Δ(7)-reductase (DWARF5) and Δ(24)-sterol-Δ(24)-reductase (DIMINUTO/DWARF1) show multiple subcellular localizations in Arabidopsis thaliana (Heynh) L. Sterols are crucial lipid components that regulate membrane permeability and fluidity and are the precursors of bioactive steroids. The plant sterols exist as three major forms, free sterols, steryl glycosides and steryl esters. The storage of ste...

Zinser, E.; Paltauf, F.; Daum, G., 1993: Sterol composition of yeast organelle membranes and subcellular distribution of enzymes involved in sterol metabolism. Organelles of the yeast Saccharomyces cerevisiae were isolated and analyzed for sterol composition and the activity of three enzymes involved in sterol metabolism. The plasma membrane and secretory vesicles, the fractions with the highest sterol c...

Bradford, B.; Moore, L.D.; Orcutt, D.M., 1982: The free sterol, steryl ester, and steryl glycoside content of tomato cultivars resistant and susceptible to Phytophthora infestans. Leaf sterols were extracted from 3 late resistant (Nova, New Yorker and West Virginia) and 3 late susceptible (Beefsteak, Jubilee and San Marzano) tomato cvs. There were no significant differences either quantitatively or qualitatively between the...

Bradford B.; Moore L.D.; Orcutt D.M., 1982: The free sterol steryl ester and steryl glycoside content of tomato lycopersicon esculentum cultivars resistant and susceptible to phytophthora infestans. Leaf sterols were extracted from 3 late blight resistant ('Nova', 'New Yorker' and 'West Virginia 63') and 3 late blight susceptible ('Beefsteak', 'Jubilee' and 'San Marzano') cultivars o...

Sugai, M.; Takakuwa, N.; Ohnishi, M.; Urashima, T.; Oda, Y., 2009: Characterization of sterol lipids in Kluyveromyces lactis strain M-16 accumulating a high amount of steryl glucoside. Kluyveromyces lactis strain M-16 isolated from raw milk accumulates a high amount of steryl glucoside in the cells. Under high temperature or in the presence of NaCl, this strain did not show better growth than other K. lactis strains that hardly...

Merris, M.; Kraeft, J.; Tint, G.S.; Lenard, J., 2004: Long-term effects of sterol depletion in C. elegans: sterol content of synchronized wild-type and mutant populations. Three major long-term effects of sterol deprivation in Caenorhabditis elegans are described. 1) The life expectancy of sterol-deprived wild-type animals is decreased by more than 40%. Similar decreases are found in animals carrying mutations in th...

Tuckey, D.M.; Orcutt, D.M., 1999: Comparison of the free sterol and steryl ester composition of sterol-inhibiting fungicide sensitive and tolerant non-target Chlorella species. Plant Biology (Rockville) : 76

James, C.S.; Hargreaves, J.A.; Loeffler, R.S.T.; Burden, R.S., 1992: Effect of morpholine-like fungicides on growth and sterol composition of a wild-type strain and a sterol mutant of Ustilago maydis defective in sterol D-8 fwdarw -DELTA-7 isomerase activity. THE BRITISH CROP PROTECTION COUNCIL [Author] Brighton Crop Protection Conference: Pests and Diseases, Vols 1, 2 and 3 : 3) 215-220