Srivastava Vibha, Thomson James
Department of Crop, Soil & Environmental Science, University of Arkansas, Fayetteville, AR, USA.
USDA-ARS-CIU, Albany, CA, USA.
Plant Biotechnol J. 2016 Feb;14(2):471-82. doi: 10.1111/pbi.12459. Epub 2015 Aug 30.
Efficient methods of stacking genes into plant genomes are needed to expedite transfer of multigenic traits to crop varieties of diverse ecosystems. Over two decades of research has identified several DNA recombinases that carryout efficient cis and trans recombination between the recombination sites artificially introduced into the plant chromosome. The specificity and efficiency of recombinases make them extremely attractive for genome engineering. In plant biotechnology, recombinases have mostly been used for removing selectable marker genes and have rarely been extended to more complex applications. The reversibility of recombination, a property of the tyrosine family of recombinases, does not lend itself to gene stacking approaches that involve rounds of transformation for integrating genes into the engineered sites. However, recent developments in the field of recombinases have overcome these challenges and paved the way for gene stacking. Some of the key advancements include the application of unidirectional recombination systems, modification of recombination sites and transgene site modifications to allow repeated site-specific integrations into the selected site. Gene stacking is relevant to agriculturally important crops, many of which are difficult to transform; therefore, development of high-efficiency gene stacking systems will be important for its application on agronomically important crops, and their elite varieties. Recombinases, by virtue of their specificity and efficiency in plant cells, emerge as powerful tools for a variety of applications including gene stacking.
需要高效的方法将基因堆叠到植物基因组中，以加速将多基因性状转移到不同生态系统的作物品种中。二十多年的研究已经鉴定出几种DNA重组酶，它们能在人工导入植物染色体的重组位点之间进行高效的顺式和反式重组。重组酶的特异性和效率使其在基因组工程中极具吸引力。在植物生物技术中，重组酶大多用于去除选择标记基因，很少扩展到更复杂的应用。重组的可逆性是酪氨酸家族重组酶的一个特性，它不适用于涉及多轮转化以将基因整合到工程位点的基因堆叠方法。然而，重组酶领域的最新进展克服了这些挑战，为基因堆叠铺平了道路。一些关键进展包括单向重组系统的应用、重组位点的修饰和转基因位点的修饰，以允许在选定位点进行重复的位点特异性整合。基因堆叠与农业上重要的作物相关，其中许多作物难以转化；因此，开发高效的基因堆叠系统对于其在农艺上重要的作物及其优良品种上的应用至关重要。重组酶凭借其在植物细胞中的特异性和效率，成为包括基因堆叠在内的各种应用的强大工具。
