Benhassaine-Kesri Ghouziel, Aid Fatiha, Demandre Chantal, Kader Jean-Claude, Mazliak Paul
Laboratoire de Physiologie Cellulaire et Moléculaire, Université Pierre et Marie Curie (CNRS UMR 7632, Tour 53, Case 154), 4 Place Jussieu, F-75252 Paris Cedex 05, France Laboratoire de Physiologie Végétale, Institut des Sciences de la Nature, Université des Sciences et de la Technologie Houari Boumédienne, BP 39, El Alia, Bab Ez Zouar, Alger, Algérie.
Physiol Plant. 2002 Jun;115(2):221-227. doi: 10.1034/j.1399-3054.2002.1150207.x.
Rape (Brassica napus L. var. Bienvenue) is a 16:3 plant which contains predominantly prokaryotic species of monogalactosyldiacylglycerol i.e. sn-1 C18, sn-2 C16 (C18/C16 MGDG). Rape plants were exposed to a restricted water supply for 12 days. Under drought conditions, considerable changes in lipid metabolism were observed. Drought stress provoked a decline in leaf polar lipids, which is mainly due to a decrease in MGDG content. Determination of molecular species in phosphatidylcholine (PC) and MGDG indicated that the prokaryotic molecular species of MGDG (C18/C16) decreased after drought stress while the eukaryotic molecular species (C18/C18) remained stable. Drought stress had different effects on two key enzymes of PC and MGDG synthesis. The in vitro activity of MGDG synthase (EC. 2.4.1.46) was reduced in drought stressed plants whereas cholinephosphotransferase (EC. 2.7.8.2) activity was not affected. Altogether these results suggest that the prokaryotic pathway leading to MGDG synthesis was strongly affected by drought stress while the eukaryotic pathway was not. It was also observed that the molecular species of leaf PC became more saturated in drought stressed plants. This could be due to a specific decrease in oleate desaturase activity.
油菜（甘蓝型油菜品种Bienvenue）是一种16:3植物，其主要含有原核生物的单半乳糖基二酰基甘油种类，即sn-1 C18、sn-2 C16（C18/C16 MGDG）。将油菜植株置于水分供应受限的条件下12天。在干旱条件下，观察到脂质代谢发生了显著变化。干旱胁迫导致叶片极性脂质减少，这主要是由于MGDG含量降低。对磷脂酰胆碱（PC）和MGDG中分子种类的测定表明，干旱胁迫后MGDG的原核分子种类（C18/C16）减少，而真核分子种类（C18/C18）保持稳定。干旱胁迫对PC和MGDG合成的两种关键酶有不同影响。干旱胁迫植株中MGDG合酶（EC. 2.4.1.46）的体外活性降低，而胆碱磷酸转移酶（EC. 2.7.8.2）的活性未受影响。总体而言，这些结果表明导致MGDG合成的原核途径受到干旱胁迫的强烈影响，而真核途径则未受影响。还观察到干旱胁迫植株中叶片PC的分子种类变得更加饱和。这可能是由于油酸去饱和酶活性的特异性降低。
