Programa de Pós-Graduação em Genética e Biologia Molecular, Departmento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Brazil.
Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Departamento de Biologia Celular, Embriologia e Genética (UFSC), Brazil.
Prog Lipid Res. 2019 Jan;73:46-64. doi: 10.1016/j.plipres.2018.12.001. Epub 2018 Dec 4.
Triacylglycerols (TAG) are the major form of energy storage in plants. TAG are primarily stored in seeds and fruits, but vegetative tissues also possess a high capacity for their synthesis and storage. These storage lipids are essential to plant development, being used in seedling growth during germination, pollen development, and sexual reproduction, for example. TAG are also an important source of edible oils for animal and human consumption, and are used for fuel and industrial feedstocks. The canonical pathway leading to TAG synthesis is the glycerol-3-phosphate, or Kennedy, pathway, which is an evolutionarily conserved process in most living organisms. The enzymatic machinery for synthesizing TAG is well known in several plant species, and the genes encoding these enzymes have been the focus of many studies. Here, we review recent progress on the understanding of evolutionary, functional and biotechnological aspects of the glycerol-3-phosphate pathway enzymes that produce TAG. We discuss current knowledge about their functional aspects, and summarize valuable insights into genetically engineered plants for enhancing TAG accumulation. Also, we highlight the evolutionary history of these genes and present a meta-analysis linking positive selection to gene family and plant diversification, and also to the domestication processes in oilseed crops.
三酰基甘油（TAG）是植物中主要的储能形式。TAG 主要储存在种子和果实中，但营养组织也具有合成和储存 TAG 的高能力。这些储存脂质对植物的发育至关重要，例如，在种子萌发、花粉发育和有性繁殖期间，幼苗生长需要它们。TAG 也是动物和人类食用油脂的重要来源，也可用于燃料和工业原料。导致 TAG 合成的典型途径是甘油-3-磷酸途径，即肯尼迪途径，这是大多数生物中进化保守的过程。几种植物中都有合成 TAG 的酶的酶机制，并且这些酶的基因一直是许多研究的焦点。在这里，我们综述了对甘油-3-磷酸途径酶产生 TAG 的进化、功能和生物技术方面的最新理解进展。我们讨论了它们功能方面的当前知识，并总结了在提高 TAG 积累方面对遗传工程植物的宝贵见解。此外，我们还强调了这些基因的进化历史，并进行了元分析，将正选择与基因家族和植物多样化以及油料作物的驯化过程联系起来。
