Gordon-Kamm Bill, Sardesai Nagesh, Arling Maren, Lowe Keith, Hoerster George, Betts Scott, Jones And Todd
Corteva Agriscience™, Agriculture Division of DowDuPont, Johnston, IA 50131, USA.
Plants (Basel). 2019 Feb 11;8(2):38. doi: 10.3390/plants8020038.
Efficient transformation of numerous important crops remains a challenge, due predominantly to our inability to stimulate growth of transgenic cells capable of producing plants. For years, this difficulty has been partially addressed by tissue culture strategies that improve regeneration either through somatic embryogenesis or meristem formation. Identification of genes involved in these developmental processes, designated here as morphogenic genes, provides useful tools in transformation research. In species from eudicots and cereals to gymnosperms, ectopic overexpression of genes involved in either embryo or meristem development has been used to stimulate growth of transgenic plants. However, many of these genes produce pleiotropic deleterious phenotypes. To mitigate this, research has been focusing on ways to take advantage of growth-stimulating morphogenic genes while later restricting or eliminating their expression in the plant. Methods of controlling ectopic overexpression include the use of transient expression, inducible promoters, tissue-specific promoters, and excision of the morphogenic genes. These methods of controlling morphogenic gene expression have been demonstrated in a variety of important crops. Here, we provide a review that highlights how ectopic overexpression of genes involved in morphogenesis has been used to improve transformation efficiencies, which is facilitating transformation of numerous recalcitrant crops. The use of morphogenic genes may help to alleviate one of the bottlenecks currently slowing progress in plant genome modification.
对许多重要作物进行高效转化仍然是一项挑战，这主要是因为我们无法刺激能够发育成植株的转基因细胞生长。多年来，通过组织培养策略，即通过体细胞胚胎发生或分生组织形成来改善再生，这一难题已得到部分解决。鉴定参与这些发育过程的基因（本文中称为形态发生基因）为转化研究提供了有用的工具。在从双子叶植物、谷类作物到裸子植物的物种中，参与胚胎或分生组织发育的基因的异位过表达已被用于刺激转基因植物的生长。然而，这些基因中的许多都会产生多效性有害表型。为了缓解这一问题，研究一直集中在如何利用刺激生长的形态发生基因，同时在后期限制或消除它们在植物中的表达。控制异位过表达的方法包括使用瞬时表达、诱导型启动子、组织特异性启动子以及切除形态发生基因。这些控制形态发生基因表达的方法已在多种重要作物中得到证实。在这里，我们提供一篇综述，重点介绍了参与形态发生的基因的异位过表达如何被用于提高转化效率，这有助于对许多难转化作物进行转化。形态发生基因的使用可能有助于缓解目前阻碍植物基因组修饰进展的瓶颈之一。
