Wright M, Dawson J, Dunder E, Suttie J, Reed J, Kramer C, Chang Y, Novitzky R, Wang H, Artim-Moore L
Syngenta fka Novartis Agribusiness Biotechnology Research, 3054 Cornwallis Rd, Research Triangle Park, NC 27709, USA, USA.
Plant Cell Rep. 2001 Jul;20(5):429-436. doi: 10.1007/s002990100318. Epub 2014 Feb 15.
A selectable marker system for plant transformation that does not require the use of antibiotics or herbicides was developed. The selectable marker consists of the manA gene from Escherichia coli under the control of a plant promoter that encodes for phosphomannose isomerase, pmi. Only transgenic plants were able to metabolize the selection agent, mannose, into a usable source of carbon, fructose. Transgenic plants were produced efficiently after delivery by Biolistics™ of the pmi gene into maize and wheat tissues, with mean transformation frequencies of 45% for maize and 20% for wheat. Adjustment of the sucrose and mannose levels in the selection medium essentially eliminated escapes. Transgenic events can be identified as early as 2 months for wheat and 4 months for maize. A simple test, a modified chlorophenol red assay, was used for early identification of transgenic events expressing the pmi gene. Transformation frequencies for both crops exceeded those obtained with the bar and pat genes with selection on either Basta or bialaphos.
开发了一种用于植物转化的选择标记系统，该系统无需使用抗生素或除草剂。该选择标记由来自大肠杆菌的manA基因组成，其受植物启动子控制，该启动子编码磷酸甘露糖异构酶（pmi）。只有转基因植物能够将选择剂甘露糖代谢成可用的碳源果糖。通过生物弹道法将pmi基因导入玉米和小麦组织后，有效地产生了转基因植物，玉米的平均转化频率为45%，小麦为20%。调整选择培养基中的蔗糖和甘露糖水平基本上消除了逃逸现象。对于小麦，最早可在2个月时鉴定出转基因事件；对于玉米，则为4个月。一种简单的测试方法，即改良的氯酚红测定法，用于早期鉴定表达pmi基因的转基因事件。两种作物的转化频率均超过了使用bar和pat基因在草铵膦或双丙氨膦上进行选择时获得的频率。
