Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyacids naturally synthesized in bacteria as a carbon reserve. PHAs have properties of biodegradable thermoplastics and elastomers and their synthesis in crop plants is seen as an attractive system for the sustained production of large amounts of polymers at low cost. A variety of PHAs having different physical properties have now been synthesized in a number of transgenic plants, including Arabidopsis thaliana, rape and corn. This has been accomplished through the creation of novel metabolic pathways either in the cytoplasm, plastid or peroxisome of plant cells. Beyond its impact in biotechnology, PHA production in plants can also be used to study some fundamental aspects of plant metabolism. Synthesis of PHA can be used both as an indicator and a modulator of the carbon flux to pathways competing for common substrates, such as acetyl-coenzyme A in fatty acid biosynthesis or 3-hydroxyacyl-coenzyme A in fatty acid degradation. Synthesis of PHAs in plant peroxisome has been used to demonstrate changes in the flux of fatty acids to the beta-oxidation cycle in transgenic plants and mutants affected in lipid biosynthesis, as well as to study the pathway of degradation of unusual fatty acids.

中文翻译：

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植物中的聚羟基链烷酸酯合成，作为生物技术和脂质代谢基础研究的工具。

聚羟基链烷酸酯（PHA）是在细菌中自然合成的羟基酸聚酯，可作为碳储备。PHA具有可生物降解的热塑性塑料和弹性体的特性，它们在农作物中的合成被视为吸引人们持续低成本生产大量聚合物的系统。现在已经在许多转基因植物中合成了具有不同物理性质的多种PHA，包括拟南芥，油菜和玉米。这是通过在植物细胞的细胞质，质体或过氧化物酶体中建立新的代谢途径来实现的。除了对生物技术的影响外，植物中PHA的产生还可以用于研究植物代谢的一些基本方面。PHA的合成可以用作通向竞争性底物的途径的碳通量的指示剂和调节剂，例如在脂肪酸生物合成中的乙酰辅酶A或在脂肪酸降解中的3-羟酰基辅酶A。植物过氧化物酶体中PHAs的合成已被用于证明在脂类生物合成中受影响的转基因植物和突变体中脂肪酸通量向β-氧化循环的变化，以及研究异常脂肪酸的降解途径。