Huner N P, Krol M, Williams J P, Maissan E, Low P S, Roberts D, Thompson J E
Department of Plant Sciences, University of Western Ontario, London, Ontario, Canada N6A 5B7.
Plant Physiol. 1987 May;84(1):12-8. doi: 10.1104/pp.84.1.12.
Lipid and fatty acid analyses were performed on whole leaf extracts and isolated thylakoids from winter rye (Secale cereale L. cv Puma) grown at 5 degrees C cold-hardened rye (RH) and 20 degrees C nonhardened rye (RNH). Although no significant change 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-Delta(3)-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(1):LHCII(3)) 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 5 degrees C indicated that both, the trans-16:1 acid levels in PG and the LHCII(1):LHCII(3) decreased concomitantly with a decrease in growth temperature. Above 40 degrees C, differential scanning calorimetry of RNH thylakoids indicated the presence of five major endotherms (47, 60, 67, 73, and 86 degrees C). Although the general features of the temperature transitions observed above 40 degrees C in RH thylakoids were similar to those observed for RNH thylakoids, the transitions at 60 and 73 degrees C were resolved as inflections only and RH thylakoids exhibited transitions at 45 and 84 degrees C which were 2 degrees C lower than those observed in RNH thylakoids. Since polypeptide and lipid compositions of RH and RNH thylakoids were very similar, we suggest that these differences reflect alterations in thylakoid membrane organization. Specifically, it is suggested that low developmental temperature modulates LHCII organization such that oligomeric LHCII predominates in RNH thylakoids whereas a monomeric or an intermediate form of LHCII predominates in RH thylakoids. Furthermore, we conclude that low developmental temperature modulates LHCII organization by specifically altering the fatty composition of thylakoid PG.
对在5摄氏度下冷驯化的黑麦（Secale cereale L. cv Puma）以及在20摄氏度下未驯化的黑麦（RNH）的全叶提取物和分离的类囊体进行了脂质和脂肪酸分析。尽管未观察到总脂质含量有显著变化，但在低温冷驯化温度下生长导致与磷脂酰二酰甘油（PG）相关的反式Δ(3)-十六碳烯酸（反式-16:1）水平在类囊体中特定降低了67%，在全叶中降低了74%。电子自旋共振和差示扫描量热法（DSC）表明，冷驯化黑麦（RH）和未驯化黑麦（RNH）类囊体的流动性没有显著差异。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离叶绿素-蛋白质复合物表明，未驯化黑麦类囊体中寡聚捕光复合物与单体捕光复合物的比例（LHCII(1):LHCII(3)）比冷驯化黑麦类囊体高2倍。CP1a:CP1的比例在未驯化黑麦类囊体中也比冷驯化黑麦类囊体高1.5倍。对在20、15、10和5摄氏度下生长的冬黑麦的分析表明，PG中的反式-16:1酸水平和LHCII(1):LHCII(3)均随生长温度的降低而同时降低。在40摄氏度以上，未驯化黑麦类囊体的差示扫描量热法表明存在五个主要吸热峰（47、60、67、73和86摄氏度）。尽管在40摄氏度以上观察到的冷驯化黑麦类囊体温度转变的一般特征与未驯化黑麦类囊体相似，但60和73摄氏度处仅分辨为拐点，且冷驯化黑麦类囊体在45和84摄氏度处出现转变，比未驯化黑麦类囊体低2摄氏度。由于冷驯化黑麦和未驯化黑麦类囊体的多肽和脂质组成非常相似，我们认为这些差异反映了类囊体膜组织的改变。具体而言，有人提出低发育温度调节LHCII的组织，使得寡聚LHCII在未驯化黑麦类囊体中占主导，而单体或中间形式的LHCII在冷驯化黑麦类囊体中占主导。此外，我们得出结论，低发育温度通过特异性改变类囊体PG的脂肪酸组成来调节LHCII的组织。
