The early flowering system HSP::AtFT allowed a fast evaluation of a gene containment system based on the construct PsEND1::barnase-barstar for poplar. Transgenic lines showed disturbed pollen development and sterility. Vertical gene transfer through pollen flow from transgenic or non-native plant species into their crossable natural relatives is a major concern. Gene containment approaches have been proposed to reduce or even avoid gene flow among tree species. However, evaluation of genetic containment strategies for trees is very difficult due to the long-generation times. Early flowering induction would allow faster evaluation of genetic containment in this case. Although no reliable methods were available for the induction of fertile flowers in poplar, recently, a new early flowering approach was developed. In this study, early flowering poplar lines containing the gene construct PsEND1::barnase-barstar were obtained. The PsEND1 promoter was chosen due to its early expression pattern, its versality and efficiency for generation of male-sterile plants fused to the barnase gene. RT-PCRs confirmed barnase gene activity in flowers, and pollen development was disturbed, leading to sterile flowers. The system developed in this study represents a valuable tool for gene containment studies in forest tree species.

中文翻译：

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通过早期开花诱导对杨树基因控制系统的有效评估。

早期开花系统 HSP::AtFT 允许快速评估基于构建体 PsEND1::barnase-barstar 用于杨树的基因遏制系统。转基因品系表现出受干扰的花粉发育和不育。通过花粉流从转基因或非本地植物物种到其可杂交的天然亲属的垂直基因转移是一个主要问题。已经提出了基因遏制方法来减少甚至避免树种之间的基因流动。然而，由于世代时间长，对树木的遗传遏制策略进行评估非常困难。在这种情况下，早期开花诱导将允许更快地评估遗传遏制。尽管没有可靠的方法可用于在杨树中诱导可育花，但最近开发了一种新的早期开花方法。在这项研究中，获得了含有基因构建体 PsEND1::barnase-barstar 的早开花杨树品系。选择 PsEND1 启动子是因为它的早期表达模式、其通用性和产生与 barnase 基因融合的雄性不育植物的效率。RT-PCRs证实了花中的barnase基因活性，花粉发育受到干扰，导致不育花。本研究中开发的系统代表了森林树种基因遏制研究的宝贵工具。