英语翻译Maintenance of polyunsaturated fatty acid levels inchlor

英语翻译
Maintenance of polyunsaturated fatty acid levels in
chloroplast lipids has been shown to contribute to low
temperature survival and the normal formation of
chloroplastmembranes under chilling stress (Routaboul
et al.2000; Iba 2002).Both the Arabidopsis fad5
mutant,which lacks an active chloroplast x-9 fatty acid
desaturase and accumulates high levels of palmitic acid
(16:0),and the fad6 mutant,which lacks an active x-6
fatty acid desaturase and accumulates high levels of
palmitoleic acid (16:1) and oleic acid (18:1),have
reduced levels of polyunsaturated fatty acids in the
chloroplast galactolipids.Seedlings of these mutants
subjected to chilling stress became chlorotic and had
half the chlorophyll content of wild-type.In addition,
the number of thylakoid membranes in these mutants
decreased and their chloroplasts were smaller.The
Arabidopsis fad2 mutant,deficient in an endoplasmic
reticulum (ER) localized x-6 desaturase,had significantly
decreased polyunsaturates in the extrachloroplast
membrane lipids.Long term culture of these mutant
plants at low temperature (6\2C) eventually resulted in
their withering and death,but not for wild-type plants
(Miquel et al 1993).Recent findings suggest that plants
capable of cold acclimation accumulate polyunsaturates
during cold stress.Cold acclimating potato (Solanum
commersonii) was found to accumulate linoleic acid
(18:2) in the membrane glycerolipids of the leaves,
whereas commercial,non-acclimating potato (Solanum
tuberosum) did not show this trait during cold stress

研究显示,在叶绿体脂中维持一定的多不饱和脂肪酸水平有助于在寒冷的生存压力下的生存和叶绿体膜的正常形成（ Routaboul等,2000年； Iba 2002年） .两个拟南芥突变体的叶绿体半乳糖脂含有较少的多不饱和脂肪酸：一种是拟南芥fad5突变体,它缺乏有活性的叶绿体的X-9脂肪酸去饱和酶,因而积累了高浓度的棕榈酸（ 16:0 ） ；另一种是拟南芥fad6突变体,它缺乏一个有活性的 X - 6脂肪酸脱氢酶因而积累了高浓度的软脂酸（ 16:1 ）和油酸（ 18:1 ） .这些突变种的幼苗株在遭受低温胁迫时,比起野生型,叶绿素含量少了一半.此外,在这些突变体中,类囊体膜的数量也有所降低,它们的叶绿体亦相对较小.拟南芥fad2突变体则缺乏一个内质网（ ER ）定位的X-6去饱和酶,它的多不饱和脂肪酸在叶绿体外膜脂中含量显著减少.在低温（ 6度）长期培养这些突变植物最终导致了他们的枯萎和死亡,而野生型植物就不会如此（Miquel等人1993年） .最近的研究结果表明,耐寒的植物在寒冷刺激下能够积累多不饱和脂肪酸.耐寒马铃薯（ Solanum commersonii ）被发现会在叶子的膜甘油脂中积累亚油酸（ 18:2 ）；而商售的、非耐寒的马铃薯（ Solanum tuberosum）就在寒冷刺激下没有表现出这种特质.
自己翻译的.不是机器译的.