Abstract

Acyl lipids and pigments were analyzed in young plants of garden pea, spring wheat and spinach exposed to <5 or 65 nl l(-1) ozone 12 h per day for 6 days. In one set of experiments, the plants were exposed to (CO2)-C-14 for 2 h 3 days prior to ozone exposure. The plants responded differently to the moderately enhanced level of ozone used Spinach was not at all sensitive while in both pea and wheat, leaves of different ages differed in ozone sensitivity. In pea, ozone sensitivity increased with leaf age. In the second and third oldest leaves, the amounts of galactolipids per leaf area and the proportions of 18:3 of the total lipid extract and of phosphatidylglycerol decreased. In the second oldest leaf, ozone also caused a decreased proportion of 18:3 of monogalactosyldiacylglycerol. In the fourth oldest leaf, Lipid composition and galactolipid unsaturation was unaffected, but ozone caused decreased leaf expansion resulting in increased acyl lipid content per leaf area. In both the first and second leaves of wheat, ozone fumigation caused a marked decrease in the content of monogalactosyldiacylglycerol and in the first leaf, the contents of phosphatidylcholine and phosphatidylethanolamine increased. The proportion of 18:3 in phosphatidylcholine was larger in ozone-fumigated than in control plants, while the reverse applied for phosphatidylglycerol. In the oldest sampled leaves of pea and wheat, ozone caused an increase in the radioactivity associated with beta-carotene, indicating increased turnover. Thus, while spinach was unaffected, in both pea and wheat ozone caused a decrease in the proportion of chloroplast membrane lipids to non-chloroplast membrane lipids in older leaves while younger leaves were less sensitive.

Keywords

acyl lipid; carotenoid; chlorophyll; chloroplast lipid; digalactosyldiacylglycerol; galactolipid; lipid metabolism; monogalactosyldiacylglycerol; ozone; pea; phosphatidylcholine; phosphatidylethanolamine; phospholipid; Pisum sativum; spinach; Triticum aestivum; Spinacia oleracea; wheat

Published in

Physiologia Plantarum
1996, Volume: 98, number: 2, pages: 271-280
Publisher: MUNKSGAARD INT PUBL LTD

UKÄ Subject classification

Biochemistry and Molecular Biology
Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1034/j.1399-3054.1996.980208.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/90666