Department of Biotechnology and Food Microbiology, Faculty of Biotechnology and Food Sciences, Wrocław University of Environmental and Life Sciences, Chełmońskiego St. 37, 51-630, Wrocław, Poland.
Department of Plant Physiology, Faculty of Biotechnology, University of Rzeszów, Rzeszów, Poland.
Transgenic Res. 2019 Feb;28(1):77-90. doi: 10.1007/s11248-018-0105-y. Epub 2018 Nov 27.
The high demand for new biomaterials makes synthesis of polyhydroxyalkanoates (PHA) in plants an interesting and desirable achievement. Production of polymers in plants is an example of application of biotechnology for improving the properties of plants, e.g. industrial properties, but it can also provide knowledge about plant physiology and metabolism. The subject of the present study was an industrially important plant: flax, Linum usitatissimum L., of a fibre cultivar (cv Nike). In the study the gene encoding PHA synthase from Pseudomonas aeruginosa, fused to a peroxisomal targeting signal, was expressed in flax plants with the aim of modifying the mechanical properties of plants. Medium-chain-length (mcl) hydroxy acids in flax plants from tissue cultures were detected by GC-FID and FTIR method. The introduced changes did not affect fatty acid content and composition in generated flax plants. Since mcl-PHA are known as elastomers, the mechanical properties of created plants were examined. Modified plants showed increases in the values of all measured parameters (except strain at break evaluated for one modified line). The largest increase was noted for tensile stiffness, which was 2- to 3-fold higher than in wild-type plants. The values estimated for another parameter, Young's modulus, was almost at the same level in generated flax plants, and they were about 2.7-fold higher when compared to unmodified plants. The created plants also exhibited up to about 2.4-fold higher tensile strength. The observed changes were accompanied by alterations in the expression of selected genes, related to cell wall metabolism in line with the highest expression of phaC1 gene. Biochemical data were confirmed by spectroscopic methods, which also revealed that crystallinity index values of cellulose in modified flax plants were increased in comparison to wild-type flax plants and correlated with biomechanical properties of plants.
对新型生物材料的巨大需求使得聚羟基脂肪酸酯（PHA）在植物中的合成成为一个有趣且理想的目标。在植物中生产聚合物是生物技术应用于改善植物特性（例如工业特性）的一个实例，但它也可以提供有关植物生理学和新陈代谢的知识。本研究的主题是一种具有工业重要性的植物：亚麻，Linum usitatissimum L.，纤维品种（cv Nike）。在研究中，将来自铜绿假单胞菌的 PHA 合酶基因与过氧化物酶体靶向信号融合表达在亚麻植物中，目的是修饰植物的机械性能。通过 GC-FID 和 FTIR 方法检测组织培养的亚麻植物中的中链长度（mcl）羟基酸。引入的变化不会影响生成的亚麻植物中的脂肪酸含量和组成。由于 mcl-PHA 已知为弹性体，因此检查了创建植物的机械性能。改良植物的所有测量参数值均增加（仅对一条改良线评估的断裂伸长率除外）。最大的增加发生在拉伸刚度上，比野生型植物高 2-3 倍。在生成的亚麻植物中，估计的另一个参数杨氏模量的值几乎相同，与未改性植物相比，增加了近 2.7 倍。创建的植物还表现出高达约 2.4 倍的拉伸强度。观察到的变化伴随着与细胞壁代谢相关的选定基因表达的改变，与 phaC1 基因的最高表达一致。生化数据得到了光谱方法的证实，该方法还表明，与野生型亚麻植物相比，改良的亚麻植物中纤维素的结晶度指数值增加，并与植物的生物力学特性相关。
