Taxonomic implication of sterol composition in the genusChlorella

Lipids ◽  
1982 ◽  
Vol 17 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Marcia J. Holden ◽  
Glenn W. Patterson
Keyword(s):  
Sterol Composition ◽  
Taxonomic Implication

138 LIPID CHANGES IN TOMATO FRUIT MICROSOMAL MEMBRANES DURING RIPENING

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 448d-448
Author(s):  
Bruce D. Whitaker
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Physical Properties ◽  
Free Sterol ◽  
Tomato Fruit ◽  
Sterol Composition ◽  
Steryl Glycoside ◽  
Microsomal Membranes ◽  
Fruit Pericarp ◽  
Total Membrane

A previous study of lipids from pericarp tissue of tomato fruit ranging from mature-green to red-ripe showed a large increase in total sterols accompanied by dramatic changes in sterol composition and conjugation with ripening. This study was conducted to determine whether similar changes occur in microsomal membranes derived from tomato fruit pericarp. Acylated steryl glycoside (ASG), the predominant steryl lipid, declined during ripening, with increases in steryl glycoside (SG) and free sterol (FS). Only minor changes in fatty acid composition were associated with the drop in ASG. The stigmasterol:sitosterol ratio increased throughout ripening, but much more in Fs than in SG or ASG. The ratio of FS to phospholipid (PL) increased with ripening. However, FS was never greater than 10 percent of the total membrane sterol (TMS), and TMS:PL actually declined over the middle stages of ripening. It is not known why tomato tissues maintain such high levels of ASG and SG, but sterol conjugation is thought to regulate the physical properties of cell membranes.

scholarly journals Membrane Sterol Composition in Arabidopsis thaliana Affects Root Elongation via Auxin Biosynthesis

2021 ◽  
Vol 22 (1) ◽  
pp. 437
Author(s):  
Meng Wang ◽  
Panpan Li ◽  
Yao Ma ◽  
Xiang Nie ◽  
Markus Grebe ◽  
...  
Keyword(s):  
Root Elongation ◽  
Auxin Transport ◽  
Sterol Composition ◽  
Polar Auxin Transport ◽  
Sterol Biosynthesis ◽  
Auxin Biosynthesis ◽  
Root Tip ◽  
Auxin Signaling ◽  
Auxin Response ◽  
Short Root

Plant membrane sterol composition has been reported to affect growth and gravitropism via polar auxin transport and auxin signaling. However, as to whether sterols influence auxin biosynthesis has received little attention. Here, by using the sterol biosynthesis mutant cyclopropylsterol isomerase1-1 (cpi1-1) and sterol application, we reveal that cycloeucalenol, a CPI1 substrate, and sitosterol, an end-product of sterol biosynthesis, antagonistically affect auxin biosynthesis. The short root phenotype of cpi1-1 was associated with a markedly enhanced auxin response in the root tip. Both were neither suppressed by mutations in polar auxin transport (PAT) proteins nor by treatment with a PAT inhibitor and responded to an auxin signaling inhibitor. However, expression of several auxin biosynthesis genes TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1) was upregulated in cpi1-1. Functionally, TAA1 mutation reduced the auxin response in cpi1-1 and partially rescued its short root phenotype. In support of this genetic evidence, application of cycloeucalenol upregulated expression of the auxin responsive reporter DR5:GUS (β-glucuronidase) and of several auxin biosynthesis genes, while sitosterol repressed their expression. Hence, our combined genetic, pharmacological, and sterol application studies reveal a hitherto unexplored sterol-dependent modulation of auxin biosynthesis during Arabidopsis root elongation.

scholarly journals Changes in genetic constitution and sterol composition during growth of nystatin-resistant heterokaryons ofNeurospora crassa

1983 ◽  
Vol 42 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Jill E. Ogden ◽  
Morris Grindle
Keyword(s):  
Growth Rates ◽  
Minimal Medium ◽  
Resistant Mutant ◽  
Sterol Composition ◽  
Sensitive Strain ◽  
Genetic Constitution ◽  
Polyene Antibiotic ◽  
Ofneurospora Crassa ◽  
Synthetic Media ◽  
Selection Of

SUMMARYHeterokaryons ofN. crassawere synthesized from homokaryotic strains differing in sterol composition and sensitivity to the polyene antibiotic nystatin. Mycelia of the nystatin-sensitive strainerg-1+contained ergosterol and episterol, and the nystatin-resistant mutanterg-1 contained fecosterol and lichesterol. Mycelia of heterokaryons with different proportions oferg-1+:erg-1 nuclei contained various proportions of the four sterols. Ergosterol was the principal sterol in heterokaryons with more than 5%erg-1+nuclei.Heterokaryons with various proportions oferg-1+:erg-1 nuclei were grown for several weeks along tubes of synthetic media. Growth rates were stable on minimal medium and nutritionally supplemented media but nuclear proportions often fluctuated. Growth rates fell sharply on nystatin-supplemented media and there were adaptive increases in proportions of mutanterg-1 nuclei which resulted in selection of nystatin-resistant homokaryotic mycelia.

Sterol composition of twelve chlorophyceae from the senegalese coast and their chemotaxonomic significance

1992 ◽  
Vol 31 (12) ◽  
pp. 4167-4169 ◽  
Author(s):  
M. Aknin ◽  
R. Moellet-Nzaou ◽  
J.M. Kornprobst ◽  
E.M. Gaydou ◽  
A. Samb ◽  
...  
Keyword(s):  
Sterol Composition

scholarly journals Sterol composition of dinoflagellates: Different abundance and composition in heterotrophic species and resting cysts

2010 ◽  
Vol 44 (3) ◽  
pp. 225-231 ◽  
Author(s):  
MIKI AMO ◽  
NORIYUKI SUZUKI ◽  
HIROSHI KAWAMURA ◽  
AIKA YAMAGUCHI ◽  
YOSHIHITO TAKANO ◽  
...  
Keyword(s):  
Sterol Composition ◽  
Resting Cysts

Changes in sterol composition with ontogeny of Blumeria graminis conidia

2000 ◽  
Vol 78 (10) ◽  
pp. 1288-1293 ◽  
Author(s):  
Jérôme Muchembled ◽  
Anissa Lounès-Hadj Sahraoui ◽  
Anne Grandmougin-Ferjani ◽  
Michel Sancholle
Keyword(s):  
Powdery Mildew ◽  
Plant Pathogen ◽  
Total Sterol ◽  
Sterol Composition ◽  
Blumeria Graminis ◽  
Erysiphe Graminis ◽  
Qualitative And Quantitative ◽  
Wheat Powdery Mildew

The total sterol composition of conidia of the obligate plant pathogen Blumeria (= Erysiphe) graminis f.sp. tritici has been analysed as a function of their ontogeny during sporulation. Two main classes of sterols were characterized: 24-ethylsterols (24-ethylcholesta-5,22-dienol, 24-ethylcholesterol, and Δ5-avenasterol) and 24-methylsterols (24-methylenecholesterol and episterol). Our results show that sterol composition is greatly modified during ontogeny of B. graminis conidia both at the qualitative and quantitative levels. In particular, 24-methylsterols, e.g., 24-methylenecholesterol and episterol, are the major sterols in old conidia whereas 24-ethylsterols, e.g., 24-ethylcholesta-5,22-dienol, 24-ethylcholesterol, and Δ5-avenasterol, are the main sterols in young conidia.Key words: Erysiphe, wheat powdery mildew, sterols, ontogeny.

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