Acrolein is formed from trienoic fatty acids in chloroplast: A targeted metabolomics approach
Acrolein is formed from trienoic fatty acids in chloroplast: A targeted metabolomics approach
复制标题
DOI：
10.5511/plantbiotechnology.14.1112a
复制
发表时间：
2014-12-01
影响因子：
1.6
通讯作者：
Shibata, Daisuke
中科院分区：
文献类型：
--
作者：
Mano, Jun'ichi;Khorobrykh, Sergey;Shibata, Daisuke
脂质过氧化物（氧脂质羰基）产生的醛和酮具有多种生物活性，从诱导防御基因到对细胞的不可逆损伤。短氧脂类羰基如丙烯醛和(E)-2-戊烯醛是环境胁迫下组织损伤的原因，但其产生机制尚不清楚。在本研究中，我们阐明了叶片中短氧脂羰基的来源脂肪酸。我们首先建立了对氧脂类羰基进行定量和结构估计的综合分析。从拟南芥莲座叶中提取羰基，用2,4-二硝基苯肼衍生化，用配备光电二极管阵列检测器和傅里叶变换离子回旋共振质谱仪的反相高效液相色谱法分离羰基。共检出33种不同的羰基，其中MS/MS谱鉴定出19种。利用该分析系统，对两种不同脂肪酸组成的拟南芥叶片中羰基组成进行了比较。突变体fad7fad8在质体中缺乏三烯脂肪酸的生物合成，其丙二醛、丙烯醛和(E)-2-戊烯醛含量显著低于野生型col0，而丙酮、3-戊酮和正己醛含量显著高于野生型col0。这种羰基组成的差异与二烯和三烯脂肪酸的体外氧化降解一致，表明类似的非酶反应发生在类囊体膜上。从三烯脂肪酸形成丙烯醛的机理来看，叶绿体中的膜脂是由单线态氧组成氧化的。
Aldehydes and ketones produced from lipid peroxides (oxylipin carbonyls) exhibit a variety of biological activities ranging from the induction of defense genes to the irreversible damage to cells. Short oxylipin carbonyls such as acrolein and (E)-2-pentenal are responsible for tissue injury under environmental stress, but their production mechanism remains unclear. In this study, we elucidated the source fatty acids of short oxylipin carbonyls in leaves. We first established a comprehensive analysis of oxylipin carbonyls for quantitation and structural estimation. Carbonyls were extracted from rosette leaves of Arabidopsis thaliana, derivatized with 2,4-dinitrophenylhydrazine and separated with a reverse-phase HPLC equipped with a photodiode array detector and an Fourier transform ion cyclotron resonance mass spectrometer. Thirty-three distinct carbonyls were detected, in which 19 species were identified on the MS/MS spectrum. Using this analysis system, we compared the carbonyl composition in the leaves between two A. thaliana lines that have diffrent fatty acid composition. The mutant fad7fad8, which lacks the biosynthesis of trienoic fatty acids in the plastid, contained significantly lower amounts of malondialdehyde, acrolein and (E)-2-pentenal and higher amounts of acetone, 3-pentanone, and n-hexanal than the wild type Col-0. This difference in the carbonyl composition agreed with the oxidative degradation of dienoic and trienoic fatty acids in vitro, showing that similar non-enzymatic reactions occur in the thylakoid membrane. Consideration of the formation mechanism of acrolein from trienoic fatty acid suggests that membrane lipids in chloroplasts are constitutively oxidized by singlet oxygen.