Steinert Jeannette, Schiml Simon, Puchta Holger
Botanical Institute II, Karlsruhe Institute of Technology, POB 6980, 76049, Karlsruhe, Germany.
Plant Cell Rep. 2016 Jul;35(7):1429-38. doi: 10.1007/s00299-016-1981-3. Epub 2016 Apr 15.
This review summarises the recent progress in DSB-induced gene targeting by homologous recombination in plants. We are getting closer to efficiently inserting genes or precisely exchanging single amino acids. Although the basic features of double-strand break (DSB)-induced genome engineering were established more than 20 years ago, only in recent years has the technique come into the focus of plant biologists. Today, most scientists apply the recently discovered CRISPR/Cas system for inducing site-specific DSBs in genes of interest to obtain mutations by non-homologous end joining (NHEJ), which is the prevailing and often imprecise mechanism of DSB repair in somatic plant cells. However, predefined changes like the site-specific insertion of foreign genes or an exchange of single amino acids can be achieved by DSB-induced homologous recombination (HR). Although DSB induction drastically enhances the efficiency of HR, the efficiency is still about two orders of magnitude lower than that of NHEJ. Therefore, significant effort have been put forth to improve DSB-induced HR based technologies. This review summarises the previous studies as well as discusses the most recent developments in using the CRISPR/Cas system to improve these processes for plants.
本综述总结了植物中双链断裂（DSB）诱导的同源重组基因靶向技术的最新进展。我们正越来越接近有效地插入基因或精确地替换单个氨基酸。尽管20多年前就已确立了双链断裂（DSB）诱导基因组工程的基本特征，但直到近年来该技术才成为植物生物学家关注的焦点。如今，大多数科学家应用最近发现的CRISPR/Cas系统在感兴趣的基因中诱导位点特异性双链断裂，通过非同源末端连接（NHEJ）获得突变，这是植物体细胞中双链断裂修复的主要且通常不精确的机制。然而，通过双链断裂诱导的同源重组（HR）可以实现如外源基因的位点特异性插入或单个氨基酸替换等预定义的改变。尽管双链断裂的诱导极大地提高了同源重组的效率，但该效率仍比非同源末端连接低约两个数量级。因此，人们已付出巨大努力来改进基于双链断裂诱导同源重组的技术。本综述总结了以往的研究，并讨论了利用CRISPR/Cas系统改进植物相关过程的最新进展。
