Antibiotic and herbicide resistance genes are the most common marker genes for plant transformation to improve crop yield and food quality. However, there is public concern about the use of resistance marker genes in food crops due to the risk of potential gene flow from transgenic plants to compatible weedy relatives, leading to the possible development of “superweeds” and antibiotic resistance. Several selectable marker genes such as aph, nptII, aaC3, aadA, pat, bar, epsp and gat, which have been synthesized to generate transgenic plants by genetic transformation, have shown some limitations. These marker genes, which confer antibiotic or herbicide resistance and are introduced into crops along with economically valuable genes, have three main problems: selective agents have negative effects on plant cell proliferation and differentiation, uncertainty about the environmental effects of many selectable marker genes, and difficulty in performing recurrent transformations with the same selectable marker to pyramid desired genes. Recently, a simple, novel, and affordable method was presented for plant cells to convert non-metabolizable phosphite (Phi) to an important phosphate (Pi) for developing cells by gene expression encoding a phosphite oxidoreductase (PTXD) enzyme. The ptxD gene, in combination with a selection medium containing Phi as the sole phosphorus (P) source, can serve as an effective and efficient system for selecting transformed cells. The selection system adds nutrients to transgenic plants without potential risks to the environment. The ptxD/Phi system has been shown to be a promising transgenic selection system with several advantages in cost and safety compared to other antibiotic-based selection systems. In this review, we have summarized the development of selection markers for genetic transformation and the potential use of the ptxD/Phi scheme as an alternative selection marker system to minimize the future use of antibiotic and herbicide marker genes.

中文翻译：

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ptxD/Phi 作为替代选择标记系统用于生物安全问题的遗传转化：综述

抗生素和除草剂抗性基因是植物转化以提高作物产量和食品质量的最常见标记基因。然而，公众担心在粮食作物中使用抗性标记基因，因为潜在的基因从转基因植物流向相容的杂草近缘种的风险，导致“超级杂草”和抗生素抗性的可能发展。一些选择标记基因，例如 aph、nptII、aaC3、aadA、pat、bar、epsp 和 gat，已被合成以通过遗传转化产生转基因植物，但已显示出一些局限性。这些标记基因赋予抗生素或除草剂抗性并与具有经济价值的基因一起引入作物，但存在三个主要问题：选择剂对植物细胞增殖和分化有负面影响，许多选择标记基因的环境影响的不确定性，以及难以用相同的选择标记进行重复转化以金字塔所需的基因。最近，提出了一种简单、新颖且经济实惠的方法，用于植物细胞通过编码亚磷酸盐氧化还原酶 (PTXD) 酶的基因表达将不可代谢的亚磷酸盐 (Phi) 转化为重要的磷酸盐 (Pi)，用于发育细胞。ptxD 基因与含有 Phi 作为唯一磷 (P) 源的选择培养基相结合，可以作为选择转化细胞的有效系统。选择系统为转基因植物添加营养，而不会对环境造成潜在风险。ptxD/Phi 系统已被证明是一种很有前途的转基因选择系统，与其他基于抗生素的选择系统相比，它在成本和安全性方面具有几个优势。在这篇综述中，我们总结了遗传转化选择标记的发展以及 ptxD/Phi 方案作为替代选择标记系统的潜在用途，以最大限度地减少未来抗生素和除草剂标记基因的使用。