The Bar gene Glufosinate, hailing from the plasmid of Streptomyces hygroscopicus, has become a pivotal player in conferring herbicide resistance, particularly against glufosinate, in transgenic crops. Encoding the phosphinothricin acetyltransferase (PAT) enzyme, the Bar gene facilitates the acetyl transfer reaction between glufosinate, a potent herbicide, and the glutamic acid in plant cells. This transformative genetic modification equips transgenic crops with resistance to glufosinate, ushering in heightened crop yield and quality without succumbing to herbicide-induced harm during cultivation.

The Bar gene's application extends to the realm of genetic enhancement, primarily within the domain of herbicide-resistant transgenic crops. Leveraging herbicide-resistant transgenic technology enables post-planting herbicide application, eradicating unwanted weeds without compromising the transgenic crops. This technological advancement not only contributes to amplified crop yield but also reduces environmental and human health implications, concurrently diminishing overall pesticide usage. However, the utilization of the Bar gene in transgenic crops has not been without its share of debates, sparking concerns related to potential environmental and health risks. Consequently, rigorous research and oversight by scientific communities and regulatory bodies are imperative to address the safety and sustainability of transgenic crops, particularly those incorporating the Bar gene and designed for glufosinate resistance.

Since the inception of herbicide-resistant transgenic crops, researchers have tirelessly explored the nuanced distinctions between herbicide-resistant varieties and their non-transgenic counterparts. Presently, beyond the evident herbicide resistance trait, definitive evidence remains elusive. Some biologists posit that the introduction of resistance genes exclusively imparts herbicide resistance to the recipient, devoid of additional impacts. Nevertheless, ongoing discoveries suggest disparities between the two. Weed resistance typically emerges first, prompting studies on weed resistance and the corresponding sensitive expressions. For example, weeds resistant to a particular herbicide may exhibit weaker competitiveness in the absence of herbicide pressure compared to their sensitive counterparts. Building on these research findings, scientists hypothesize that, even in the absence of high herbicide selection pressure, resistant varieties necessitate synthesizing resistance proteins, consuming substantial energy and consequently displaying weaker growth competitiveness than sensitive varieties. In the context of herbicide-resistant crops, competitive differences can be scrutinized between resistant varieties and their non-transgenic counterparts.

In practical field evaluations, researchers employed gene gun technology to introduce the Bar gene into three commercially available rice varieties. DNA and RNA testing on the transgenic materials confirmed stable Bar gene integration into rice DNA, showcasing robust heritability and expression of resistance. During the four-leaf stage of rice, application of 2.12 or 2.24 kg*hm^-2 of glufosinate caused no harm to the transgenic varieties, while the non-transgenic parental lines were completely eradicated within seven days. Nevertheless, during the 1993–1994 field evaluation process, new challenges surfaced. In the absence of glufosinate, the transgenic herbicide-resistant rice exhibited delayed growth compared to the non-transgenic parental lines. While the non-transgenic parental lines had reached 50% heading, the transgenic varieties only reached 20% heading, accompanied by variations in plant height and yield. These field evaluation results underscore significant distinctions between transgenic herbicide-resistant rice and non-transgenic parental lines, especially in aspects such as plant height and maturity in the absence of glufosinate.