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

Abstract

Lipid and fatty acid analyses were perfornmed on whole leaf extracts and isolated thylakoids from winter rye (Secalk cereak L. cv Punia) grown at 5°C cold-hardened rye (RH) and 20°C nonhardened rye (RNH).Although no significant c ge in total lipid content was observed, growth at low, cold-hardening temperature resulted in a specific 67% (thylakoids) to 74% (whole leaves) decrease in the trans-A3-hexadecenoic acid (trans-16:1) level associated with phosphatidyldiacylglycerol (PG). Electron spin resonance and differential scanning calorimetry (DSC) indicated no significant difference in the fluidity of RH and RNH thylakoids. Separation of chlorophyll-protein complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the ratio of oligomeric light harvesting complex:monomeric light harvesting complex (LHCII,:LHCII3) was 2-fold higher in RNH than RH thylakoids. The ratio of CP1a:CP1 was also 1.5-fold higher in RNH than RH thylakoids. Analyses of winter rye grown at 20, 15, 10, and 5C indicated that both, the tras-16:1 acid levels in PG and the LHCII,:LHCII3 decreased concomitantly with a decrease in growth temperature. Above 40C, differential scanning calorimetry of RNH thylakoids indicated the presence of five major endotherms (47, 60, 67, 73, and 86C

Modifications to Thylakoid Composition during Development of Maize Leaves at Low Growth Temperatures

“…CPI, subunit II of PSI, DI protein, cytochromef cytochrome b6/fsubunit IV, and the a-and fsubunits of the coupling factor, is repressed as growth tem- (18) and was found to produce an increased ratio of the monomeric:oligomeric forms of LHCII when solubilized and fractionated on nondenaturing gels compared with leaves grown at 20'C (9,18). Conse-quently, it has been suggested that the cold-induced decrease in the trans-16:1 is associated with a reduced stability of the oligomeric form of LHCII in the thylakoids (10,14,18). A similar situation may account for the observed increase in the ratio of monomeric:oligomeric LHCII in maize leaves as growth temperature is decreased (Fig.…”

Control of the light‐harvesting function of chloroplast membranes by aggregation of the LHCII chlorophyll—protein complex

“…The scheme also suggests that qE would be sensitive to the boundary lipid environment; it is perhaps in this sense that the role of xanthophylls should be best regarded, a role entirely consistent with a xanthophyll requirement for reconstitution of LHCII [23]. The significance of other phenomena, such as the involvement of specific lipids in interacting with LHCII upon acclimation to low temperature [24] will perhaps b¢com.. ~ clear in terms of a role in tile regulation of energy dissipation.…”

Low Temperature-Induced Decrease in trans-Δ3-Hexadecenoic Acid Content Is Correlated with Freezing Tolerance in Cereals

“…The assignments of the various pigmented bands was based on electrophoretic migration and their characteristic absorption spectra as detailed previously (9). Upon estimation of the Chl content associated with each peak, the relative contents of PSII and PSI were calculated (Table IV).…”

“…Effects of growth temperature on the ratio of LHC111 :LHC113 in several cold tolerant plant species. The content of LHC111 and LHC113 was determined from relative peak areas of gel scans as reported previously (9)(10)(11) (17) and hence, most research on freezing resistance has focused on the composition, structure, and function of this membrane. Furthermore, it is the freezing resistance of the nonphotosynthetic crown tissue of cereals and not the leaf tissue which ultimately determines winter survival of cereals (6).…”

“…Chl-protein complexes were solubilized with DOC and SDS and separated in the dark at 4°C on 7.5% (w/v) SDS polyacrylamide slab gels as described in detail previously (9). The gels were scanned at 671 nm with a Shimadzu UV-250 spectrophotometer.…”