Nowadays, with the rapid development of biotechnology, the CRISPR/Cas technology in particular has produced many new traits and products. Therefore, rapid and high-resolution detection methods for biotechnology products are urgently needed, which is extremely important for safety regulation. Recently, in addition to being gene editing tools, CRISPR/Cas systems have also been used in detection of various targets. CRISPR/Cas systems can be successfully used to detect nucleic acids, proteins, metal ions and others in combination with a variety of technologies, with great application prospects in the future. However, there are still some challenges need to be addressed. In this review, we will list some detection methods of genetically modified (GM) crops, gene-edited crops and single-nucleotide polymorphisms (SNPs) based on CRISPR/Cas systems, hoping to bring some inspiration or ideas to readers.

Molecular characterization is a key step in the risk assessment of genetically modified organisms (GMOs) for regulatory approval. Herein, we describe a method for analyzing copy number, insertion loci, and flanking sequences through whole-genome sequencing (WGS) and bioinformatics. Comprehensive molecular characterization of G2-6 transgenic rice was performed using this pipeline. The results showed that one copy of the foreign gene was inserted into rice chromosome 8. There was no vector backbone insertion but an unexpected insertion and DNA rearrangement at the 3′ end of the T-DNA. We also obtained the 5′ and 3′ flanking sequences of the T-DNA. Our results suggested that the use of a combination of WGS and bioinformatics is an effective strategy for the molecular characterization of GMOs.

Sorghum (Sorghum bicolor) has held significant historical importance and economic value for centuries. As consumer demands have diversified in recent years, the need for sorghum in industrial sectors such as brewing and food processing has grown substantially. However, competition from weeds and damage caused by lepidopteran pests greatly limit the yield and quality of sorghum. Developing genetically modified sorghum varieties that are both herbicide tolerant and insect resistant is an effective approach to address these challenges. In this study, we stably co-expressed codon-optimized versions of the insect resistance genes mcry1Ab and mvip3A and the bar gene in sorghum using Agrobacterium-mediated genetic transformation. The genetically modified sorghum line can withstand treatment with the herbicide glufosinate at doses up to four times higher than the recommended field level and demonstrated strong resistance to lepidopteran pests such as Ostrinia furnacalis, Mythimna separata, and Spodoptera frugiperda. This new transgenic sorghum germplasm, which has enhanced resistance to both herbicides and insects, offers valuable genetic material for sorghum breeding and could help boost the competitiveness of the sorghum industry.

Cotton is one of the world’s important cash crops and occupies a significant position in agricultural production and the national economy. However, insect pests severely affect the growth, yield and quality of cotton. To ensure high and stable cotton yields, the cultivation of insect-resistant transgenic cotton via transgenic technology can not only effectively reduce the impact of chemical pesticides on crops but also exert excellent control effects against pests such as cotton bollworms. In this study, the plant expression vector pC2300-VEC harboring the target genes epsps, cry1Ac and vip3A was introduced into the genome of the recipient cotton cultivar CCRI 24 via Agrobacterium-mediated transformation. The obtained transgenic cotton plants were subjected to the identification of target genes and target traits, and the insect-resistant transgenic cotton line BrsC35 was ultimately obtained. PacBio sequencing combined with conventional molecular characterization methods was used to analyze its insertion site, copy number and other characteristics, providing a new germplasm for insect-resistant transgenic cotton.

The coexistence of genetically modified (GM) and non-GM crops has been a subject of considerable concern, particularly in the context of the extensive utilisation of GM crops. In response to this concern, various countries have devised coexistence strategies that are tailored to their respective national contexts, taking into account economic, political, technological and public acceptability factors. In the context of planting, countries such as the United States and Brazil have adopted a strategy of coexistence management, whereby the responsibility for implementing isolation measures falls upon premium producers. In contrast, the European Union, Japan and other countries that import GM crops have enacted legislation requiring growers to adhere to stringent isolation measures to prevent the mixing of GM and non-GM crops. Internationally, GM products are distinguished by a labelling management system to satisfy the public’s right to know and choose and to realise the coexistence of GM and non-GM during circulation and consumption. When considered in the context of China’s specific national conditions, particularly the prevalence of a small-scale peasant economy, it is recommended that China draw upon the lessons learned from the field coexistence strategies employed in countries that have adopted GM planting. This recommendation involves the refinement and enhancement of existing labelling management practices as well as the formulation of a coexistence management policy that is characterised by cost savings, efficiency gains and robust operational capabilities. The implementation of these measures is expected to foster the commercialisation of GM soybean and maize in China.