Effect of Frost Hardening on Lipid and Fatty Acid Composition of Chloroplast Thylakoid Membranes in Two Wheat Varieties of Contrasting Hardiness

Abstract

Lipid and fatty acid composition of chloroplast thylakoid membranes was determined in two varieties of wheat (Triticum aestivum L.), the hardy Miranovskaja and the sensitive Penjamo. Plants were grown at room temperature or under frost hardening conditions (1.5°C). Changes in lipid and fatty acid composition of the isolated thylakoids could be related to the temperature dependence of light-stimulated proton uptake. Changes in the thylakoid phospholipids upon hardening of the two varieties did not show any direct relation with low temperature tolerance of light-dependent H' uptake; neither did changes in phospholipid fatty acid chain lengthening to 20 and 22 C-atoms in combination with increased desaturation up to 6 double bonds. Increased low temperature tolerance of light-induced H' uptake by hardening was correlated with the following glycolipid changes: maintained glycolipid level, a proportionally increased digalactosyl diglyceride fraction, a decrease in thylakoid monogalactosyl diglyceride, increased sulfolipid fatty acid chain lengthening (20 and 22 C-atoms), and increased sulfolipid desaturation (4-6 double bonds). We suggest that the above mentioned changes in glycolipids have adaptive value for low temperature tolerance of lightdependent proton uptake.proportionally or remained unaffected in some species/varieties (frost-sensitive wheat variety [17]; pea and spinach [1]), whereas in the thylakoids of other species an increased DGDG/MGDG ratio was observed upon hardening (frost-resistant wheat variety, [17]; pine, [12] Growth Conditions and Hardening Procedure. Seeds of two wheat varieties (Triticum aestivum L.), the frost-sensitive Penjamo and the hardy variety Miranovskaja, sown in soil, were germinated at a day/night temperature regime of 20/12C, 16 h d-length, for 6 d. The hardening program was subsequently started by lowering the temperature gradually during 3 weeks, followed by a continuous period of 4 weeks at 1.50C, with the same light regime. After finishing the hardening, the leaves were harvested for thylakoid isolation.For the isolation of thylakoids the procedure of Lineberger and Steponkus (7) was used. Lipids were extracted as described earlier (4)

Low Temperature Development Induces a Specific Decrease in trans-Δ3-Hexadecenoic Acid Content which Influences LHCII Organization

“…Thus, we report for the first time that growth and development of rye at low, cold-hardening temperatures results in a very specific change in the fatty acid composition of PG. In contrast to the recent report of Vigh et al (29) who reported that cold-hardening of wheat results in the presence of unusual, long-chain fatty acids, we have examined two varieties of rye, wheat, and several dicotyledonous plant species and have not observed the presence of these long chain fatty acids associ-16 HUNER ET AL. (17) have shown that the EF fracture face of RNH thylakoids exhibits a bimodal particle size distribution with 150A and 100A particles similar to that reported for thylakoids from other plant species (25).…”

Functional significance of the lipid-protein interface in photosynthetic membranes

“…For instance, following a decrease in the growth temperature of Dunaliella salina from 30 to 12°C, the MGDG/DGDG ratio decreased from 3.5 to 2.1 [44]. Vigh and co-workers compared changes in the lipid compositions of thylakoid and plasma membranes, in a sensitive and in a hardy variety of wheat, induced by frost hardening [45,46]. In the frost-sensitive variety, the ratios MGDG/DGDG (2.3) and PE/phosphatidylcholine (PC) (0.35) were hardly changed.…”

Plasma Membrane Lipids Associated with Genetic Variability in Freezing Tolerance and Cold Acclimation of Solanum Species

“…Some studies reported an increase in the proportion of unsaturated fatty acids (de la Roche et al, 1972;Grenier et al, 1972;Willemot, 1975Willemot, , 1977. However, others failed to detect such an increase in fatty acid unsaturation during CA (de la Roche et al, 1975;de la Roche, 1979;Vigh et al, 1985). The contradictory results from these studies can be explained in part by the fact that many researchers have analyzed the lipid composition of whole tissues, or crude * Corresponding author; fax 1-608-262-4743. membrane or organelle preparations, rather than that of purified plasma membrane.…”