The Role of Galactolipids in Spinach Chloroplast Lamellar Membranes

Anderson, Mark M.; McCarty, Richard E.; Zimmer, Elizabeth A.

doi:10.1104/pp.53.5.699

Cited by 84 publications

(15 citation statements)

References 21 publications

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“…The enzyme is associated, at least partly, with chloroplasts (1, 1 1) and is generally assumed to be involved in the lipid catabolism (7). Although the mode of stimulative action of ozone remains to be determined, the enzyme activity is reported to be stimulated by various conditions, such as a change in pH (10,17), addition of salts (36) and detergents (1,16) to the suspending medium, and aging (10,11,17). In addition, a cystine residue is important for the activity of galactolipase purified from rice bran (16).…”

Section: Discussionmentioning

confidence: 99%

Pathway for the Synthesis of Triacylglycerols from Monogalactosyldiacylglycerols in Ozone-Fumigated Spinach Leaves

Sakaki¹,

Kondo²,

Yamada³

1990

Plant Physiol.

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When the upper leaf surface of spinach (Spinacia oleracea L.) plants was treated with [1-14C]acetate and grown for 2 days, 14Cwas effectively incorporated into acyl moieties of leaf lipids in ratios approximately their composition by mass. Fumigation of the plants with ozone (0.5 microliter per liter) caused a redistribution of 14C among lipid classes, i.e. a marked increase of 14C content in triacylglycerol (TG) and 1,2-diacylglycerol (1,2-DG) and a decrease of label in monogalactosyldiacylglycerol (MGDG) without affecting 14C distribution in leaf fatty acids. Label in both TG and 1,2-DG was found predominantly in their polyene molecular species. Since MGDG consists of similar polyene molecular species, the results indicate the synthesis of TG from MGDG via 1,2-DG. Label was also accumulated in tri-and tetragalactosyldiacylglycerol, products of galactolipid:galactolipid galactosyltransferase (GGGT). Moreover, there was a close relation between increases in the amounts of TG and the oligogalactolipids in ozonetreated leaves. These results indicate that MGDG was converted to 1,2-DG by GGGT and then to TG. In intact chloroplasts isolated from ozone-treated leaves, there was an enhanced production of free fatty acid (FFA), which was diminished by the addition of coenzyme A (CoA) and ATP, indicating that ozone stimulated the hydrolysis of MGDG to liberate FFA, which was in turn converted to acyl-CoA. The final step of TG synthesis, acylation of 1,2-DG with acyl-CoA, was confirmed by feeding with [1-14C] (27). In addition, a comparison of the molecular species between MGDG and the increased TG (28) indicated the direct conversion of 1,2-DG backbone of MGDG to TG. This paper presents labeling studies demonstrating the synthesis of TG from MGDG in ozone-fumigated spinach leaves. The results confirm the operation of the pathway from MGDG to TG via 1,2-DG and also demonstrate that MGDG is converted to 1,2-DG by GGGT. We also report that ozone stimulates the hydrolysis of MGDG to release FFA, mainly a-linolenic acid (18:3), and that the 18:3 is converted to its acyl-CoA form and then acylated to 1,2-DG to yield TG. MATERIALS AND METHODS Plant Materials and Ozone FumigationSpinach (Spinacia oleracea L., cv New Asia) plants were cultivated from seeds in a glasshouse as described previously (25). In [1-'4C]acetate-labeling experiments, expanding second leaves of rapidly growing spinach plants (4 weeks old) were used for the better incorporation of acetate into endogenous fatty acids. In the remaining experiments, youngest mature leaves of spinach plants (6-8 weeks old) were used (25,27,28). Ozone-induced lipid changes in the leaves at these different stages ofdevelopment were essentially the same as those described in the previous reports (27,28) containing lipid spots were scraped from the plate, methanolyzed, and quantified by GLC (27). Lipids in the labeled leaves and leaf discs were isolated after boiling in isopropanol for 5 min. TGDG and TTGDG were separated as described above, and other polar lipids were...

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Section: Discussionmentioning

confidence: 99%

Pathway for the Synthesis of Triacylglycerols from Monogalactosyldiacylglycerols in Ozone-Fumigated Spinach Leaves

Sakaki¹,

Kondo²,

Yamada³

1990

Plant Physiol.

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“…2 -5 ) The endogenous lipolytic enzymes, therefore, play important roles in the leaves. Galactolipase (galactolipid acyl-hydrolase, Ee 3.1.1.26) has been found in bean leaves/- 8 ) spinach leaves,9) potato tuberslo-351 and leaves,161 and rice bran.…”

Section: )mentioning

confidence: 99%

“…8 ) Fresh bean leaves were homogenized with 3 vol. (v/w) of 5 mM Tris-HCI buffer (pH 7.0) containing 0.4 M sucrose in a waring blender.…”

Section: Extraction Of Enzymementioning

confidence: 99%

Purification of a Lipolytic Acyl-hydrolase fromPhaseolus vulgarisLeaves by Affinity Chromatography on Palmitoylated Gauze and Its Properties

Matsuda¹,

Tanaka²,

Morita³

et al. 1979

Agricultural and Biological Chemistry

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“…Furthermore, even at 60 the enzyme showed considerable activity (732.2 pmol/mg/h) toward PC, whereas it was inactive toward MGDG and DGDG at this temperature. The optimal temperature for enzymatic hydrolysis of MGDG has been reported to be 37 in the red alga G. vermiculophylla 9) , the red tide alga Chattonella marina 12) , and the brown alga Cladosiphon okamuranus 8) , while the optimal temperatures of glycoglycerolipid hydrolysis in cowpea and spinach leaves are 50 and 35 , respectively 39,40) .…”

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confidence: 99%

Lipid Class and Fatty Acid Composition of a Little-known and Rarely Collected Alga Exophyllum wentii Weber-van Bosse from Bali Island, Indonesia

et al. 2009

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The lipid class and fatty acid composition of a little-known and rarely collected alga Exophyllum wentii from Bali Island, Indonesia were determined for fresh and frozen-thawed samples using thin-layer chromatography, gas-liquid chromatography, and high-performance liquid chromatography. Glycoglycerolipids, which mainly consisted of mongalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG), were the predominant lipid components, accounting for 67% and 56% of the total polar lipid content in the fresh and frozen-thawed samples, respectively. Phospholipids, including phosphatidylcholines (PC) and phosphatidylglycerols (PG), were detected with lesser amounts in both samples (16 -17% of the total polar lipid content). Free fatty acids (FFA), sterols and triacylglycerols (TAG) were also detected in minor quantities; however, the FFA content in the frozen-thawed sample increased to up to 20% of the total lipid content, suggesting that hydrolysis of the membrane lipids had occurred. A crude enzyme preparation from the alga showed activities for hydrolyzing the acyl groups of the phospholipids and glycoglycerolipids. Palmitic acid (16:0) and arachidonic acid (20:4n-6) were the major fatty acids in both the total lipid and in individual polar lipid classes as well as the dominant fatty acids released from the membrane lipids by enzymatic hydrolysis. The high level of 20:4n-6 (29%) in the total lipid and the presence of considerable amounts of PC (11% of the total polar lipid) and PG (6.2%) support classification of E. wentii into the Division Rhodophyta.

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The Role of Galactolipids in Spinach Chloroplast Lamellar Membranes

Cited by 84 publications

References 21 publications

Pathway for the Synthesis of Triacylglycerols from Monogalactosyldiacylglycerols in Ozone-Fumigated Spinach Leaves

Pathway for the Synthesis of Triacylglycerols from Monogalactosyldiacylglycerols in Ozone-Fumigated Spinach Leaves

Purification of a Lipolytic Acyl-hydrolase fromPhaseolus vulgarisLeaves by Affinity Chromatography on Palmitoylated Gauze and Its Properties

Lipid Class and Fatty Acid Composition of a Little-known and Rarely Collected Alga Exophyllum wentii Weber-van Bosse from Bali Island, Indonesia

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