Legume Genomics and Genetics 2025, Vol.16, No.5, 215-224 http://cropscipublisher.com/index.php/lgg 216 Then focus on the practical application of technologies such as CRISPR/Cas9 in the targeted improvement of lentil traits; Finally, discuss how to incorporate these techniques into the lentil breeding system, as well as the challenges and possibilities faced. We have particularly referred to the latest achievements in lentils and related crops, attempting to present a perspective that is both realistic and forward-looking to explore how lentils can achieve more sustainable development driven by technology. 2 Herbicide Resistance Mechanisms in Plants 2.1 Target site resistance (TSR) There are many ways for plants to develop resistance to herbicides, and among them, the most frequently occurring one is the so-called target resistance (TSR). In layman's terms, it means that herbicides can no longer find a "target". This type of resistance usually occurs when there is a "mistake" in the protein-coding gene of the target of herbicide action-not a loss of function, but a change in the appearance of the key part. If a mutation occurs at a certain site in the acetyllactate synthase (ALS) gene, the result is that the herbicides that were supposed to inhibit it fail. The same situation also occurs in genes such as ACCase or EPSPS, and their mutations can also render specific herbicides ineffective (Wei et al., 2022). But interestingly, most of these mutations are not "destructive", but rather like non-synonymous SNPS or small insertions/deletions that change the lock but do not affect the normal opening of the door. Nowadays, CRISPR/Cas9 and base editing tools are transforming these mutations from "accidental occurrence" to "targeted design", significantly enhancing breeding efficiency (Tian et al., 2018). 2.2 Non-target site resistance (NTSR) Not all plant resistance to drugs depends on "modifying the target". Sometimes, plants even quietly get rid of herbicides before they reach their targets-this is non-target resistance (NTSR). This resistance does not take the "direct confrontation" route but rather relies on various detour methods: some make it difficult for the herbicide to be absorbed, some prevent it from entering the cell transport channels, and others directly isolate it within the plant (Gaines et al., 2020). More commonly, it is through metabolic means to "defuse the crisis", such as cytochrome P450, glutathione S-transferase and glycosyltransferase. These enzymes are like detoxification factories in plants, breaking down herbicides in advance. These mechanisms often involve the collaborative work of multiple genes, unlike TSR which can be resolved by a single "key mutation", making breeding more challenging. Even so, with the development of genomic tools and editing methods, achieving targeted regulation in the future may not be out of reach (Dong et al., 2021). 2.3 Transgene-based resistance vs. endogenous gene editing Using foreign genes to endow plants with herbicide resistance is no longer a novelty-in the early years, the EPSPS or bar genes of bacteria were transferred into crops in this way. This approach is direct and effective, but it cannot avoid the label of genetically modified organisms. This has kept it stuck at the threshold of regulatory approval and public opinion for a long time (Hussain et al., 2021). In contrast, endogenous gene editing sounds much more low-key. It is not "borrowing genes", but making some "fine-tuning" to the existing genes of the plant itself, such as directly modifying target genes like ALS, ACCase or EPSPS (Figure 1) (Wang et al., 2020). Technical means include CRISPR/Cas9, base editing, and even oligonucleotide-induced mutations. Because no exogenous fragments are introduced, this method faces much less regulatory pressure and is more easily accepted by the market. Some current achievements also prove that this strategy is not only applicable to model plants, but also feasible in crops such as lentils, and the effect is stable, heritable and free of genetically modified labels. 3 Gene Editing Technologies for Lentil Improvement 3.1 CRISPR/Cas-based platforms The popularity of CRISPR/Cas9 is no accident. Simple, precise and highly efficient-these features have enabled it to quickly gain a firm foothold in plant gene editing. In leguminous plants, even for crops with weak technical foundations like lentils, some people have begun to attempt to use CRISPR/Cas9 to specifically knock in or knock out target genes, especially to modify traits such as herbicide resistance (Ahmar et al., 2020). To be honest, there
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