Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany.
Plant Cell Rep. 2014 Feb;33(2):245-54. doi: 10.1007/s00299-013-1525-z. Epub 2013 Oct 30.
Polyunsaturated fatty acids (PUFAs) are important cellular compounds with manifold biological functions. Many PUFAs are essential for the human diet and beneficial for human health. In this study, we report on the high amounts of very long-chain (vl) PUFAs (≥C₂₀) such as arachidonic acid (AA) in seven moss species. These species were established in axenic in vitro culture, as a prerequisite for comparative metabolic studies under highly standardized laboratory conditions. In the model organism Physcomitrella patens, tissue-specific differences in the fatty acid compositions between the filamentous protonema and the leafy gametophores were observed. These metabolic differences correspond with differential gene expression of fatty acid desaturase (FADS)-encoding genes in both developmental stages, as determined via microarray analyses. Depending on the developmental stage and the species, AA amounts for 6-31 %, respectively, of the total fatty acids. Subcellular localization of the corresponding FADS revealed the endoplasmic reticulum as the cellular compartment for AA synthesis. Our results show that vlPUFAs are highly abundant metabolites in mosses. Standardized cultivation techniques using photobioreactors along with the availability of the P. patens genome sequence and the high rate of homologous recombination are the basis for targeted metabolic engineering in moss. The potential of producing vlPUFAs of interest from mosses will be highlighted as a promising area in plant biotechnology.
多不饱和脂肪酸（PUFAs）是具有多种生物学功能的重要细胞化合物。许多 PUFAs 是人类饮食所必需的，对人类健康有益。在本研究中，我们报告了七种苔藓物种中含有大量的超长链（vl）多不饱和脂肪酸（≥C₂₀），如花生四烯酸（AA）。这些物种是在无菌体外培养中建立的，这是在高度标准化的实验室条件下进行比较代谢研究的前提。在模式生物拟南芥中，观察到丝状原丝体和叶状配子体之间的脂肪酸组成存在组织特异性差异。这些代谢差异与脂肪酸去饱和酶（FADS）编码基因的差异基因表达相对应，这是通过微阵列分析确定的。根据发育阶段和物种的不同，AA 分别占总脂肪酸的 6-31%。相应 FADS 的亚细胞定位显示内质网是 AA 合成的细胞区室。我们的研究结果表明，vlPUFAs 是苔藓中含量极高的代谢产物。使用光生物反应器进行标准化培养技术，结合 P. patens 基因组序列的可用性和高同源重组率，为苔藓中的靶向代谢工程奠定了基础。从苔藓中生产有价值的 vlPUFAs 的潜力将作为植物生物技术中一个有前途的领域得到强调。
