College of Forestry, Henan University of Science and Technology, Luoyang 471023, Henan Province, China.
Department of Chemistry, Temple University, Philadelphia, PA 19122, USA.
Int J Mol Sci. 2020 Jul 9;21(14):4854. doi: 10.3390/ijms21144854.
In recent years, plant genetic engineering has advanced agriculture in terms of crop improvement, stress and disease resistance, and pharmaceutical biosynthesis. Cells from land plants and algae contain three organelles that harbor DNA: the nucleus, plastid, and mitochondria. Although the most common approach for many plant species is the introduction of foreign DNA into the nucleus (nuclear transformation) via Agrobacterium- or biolistics-mediated delivery of transgenes, plastid transformation offers an alternative means for plant transformation. Since there are many copies of the chloroplast genome in each cell, higher levels of protein accumulation can often be achieved from transgenes inserted in the chloroplast genome compared to the nuclear genome. Chloroplasts are therefore becoming attractive hosts for the introduction of new agronomic traits, as well as for the biosynthesis of high-value pharmaceuticals, biomaterials and industrial enzymes. This review provides a comprehensive historical and biological perspective on plastid transformation, with a focus on current and emerging approaches such as the use of single-walled carbon nanotubes (SWNTs) as DNA delivery vehicles, overexpressing morphogenic regulators to enhance regeneration ability, applying genome editing techniques to accelerate double-stranded break formation, and reconsidering protoplasts as a viable material for plastid genome engineering, even in transformation-recalcitrant species.
近年来，植物基因工程在作物改良、抗逆和抗病以及药物生物合成方面推动了农业的发展。陆地植物和藻类的细胞包含三个含有 DNA 的细胞器：细胞核、质体和线粒体。虽然对于许多植物物种来说，最常见的方法是通过农杆菌或生物弹介导的转基因传递将外源 DNA 导入细胞核（核转化），但质体转化为植物转化提供了另一种方法。由于每个细胞中都有许多叶绿体基因组的拷贝，因此与核基因组相比，插入叶绿体基因组中的转基因通常可以实现更高水平的蛋白质积累。因此，叶绿体正成为引入新的农艺性状以及生物合成高价值药物、生物材料和工业酶的有吸引力的宿主。本文全面回顾了质体转化的历史和生物学观点，重点介绍了当前和新兴的方法，如将单壁碳纳米管 (SWNTs) 用作 DNA 传递载体、过表达形态发生调节剂以增强再生能力、应用基因组编辑技术加速双链断裂形成，以及重新考虑原生质体作为质体基因组工程的可行材料，即使在转化抗性物种中也是如此。
