Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA.
BMC Biotechnol. 2013 Aug 6;13:63. doi: 10.1186/1472-6750-13-63.
The introduction of pharmaceutical traits in tobacco for commercial production could benefit from the utilization of a transgene bioconfinement system. It has been observed that interspecific F1Nicotiana hybrids (Nicotiana tabacum × Nicotiana glauca) are sterile and thus proposed that hybrids could be suitable bioconfined hosts for biomanufacturing. We genetically tagged hybrids with green fluorescent protein (GFP), which was used as a visual marker to enable gene flow tracking and quantification for field and greenhouse studies. GFP was used as a useful proxy for pharmaceutical transgenes.
Analysis of DNA content revealed significant genomic downsizing of the hybrid relative to that of N. tabacum. Hybrid pollen was capable of germination in vitro, albeit with a very low frequency and with significant differences between plants. In two field experiments, one each in Tennessee and Kentucky, we detected outcrossing at only one location (Tennessee) at 1.4%. Additionally, from 50 hybrid plants at each field site, formation of 84 and 16 seed was observed, respectively. Similar conclusions about hybrid fertility were drawn from greenhouse crosses. In terms of above-ground biomass, the hybrid yield was not significantly different than that of N. tabacum in the field.
N. tabacum × N. glauca hybrids show potential to contribute to a bioconfinement- and biomanufacturing host system. Hybrids exhibit extremely low fertility with no difference of green biomass yields relative to N. tabacum. In addition, hybrids are morphologically distinguishable from tobacco allowing for identity preservation. This hybrid system for biomanufacturing would optimally be used where N. glauca is not present and in physical isolation of N. tabacum production to provide total bioconfinement.
将药物特性引入烟草进行商业生产，可以利用转基因生物隔离系统。人们观察到种间 F1 烟草杂种（Nicotiana tabacum×Nicotiana glauca）是不育的，因此提出杂种可以作为生物制造的合适生物隔离宿主。我们用绿色荧光蛋白（GFP）对杂种进行了基因标记，GFP 作为一个可视标记，用于追踪和量化田间和温室研究中的基因流动。GFP 被用作药物转基因的有用替代物。
DNA 含量分析表明，杂种相对于 N. tabacum 的基因组明显缩小。杂种花粉能够在体外萌发，尽管频率非常低，而且不同植株之间存在显著差异。在田纳西州和肯塔基州的两个田间试验中，我们仅在一个地点（田纳西州）检测到 1.4%的异交。此外，在每个田间地点的 50 株杂种植物中，分别观察到 84 粒和 16 粒种子的形成。温室杂交也得出了类似的杂种可育性结论。就地上生物量而言，杂种的产量在田间与 N. tabacum 没有显著差异。
N. tabacum×N. glauca 杂种显示出有潜力成为生物隔离和生物制造宿主系统的一部分。杂种表现出极低的育性，与 N. tabacum 相比，其绿色生物量产量没有差异。此外，杂种与烟草在形态上有区别，允许身份保存。这种用于生物制造的杂种系统最适合在没有 N. glauca 存在的情况下，以及在 N. tabacum 生产的物理隔离下使用，以实现完全的生物隔离。
