ORIGINAL ABSTRACT

BACKGROUND: Cowpea is a favorite vegetable around the world. In China, the tender pods of cowpea are the primary edible part. However, cowpea is vulnerable to a variety of pests throughout its entire growth cycle. Lepidopteran insects, including the legume pod borer (LPB, Maruca vitrata), beet armyworm (BAW, Spodoptera exigua), and tobacco cutworm (TCW, Spodoptera litura), are the major pests to cowpea production. Conventional pest management strategies predominantly rely on chemical pesticides, which not only increase production costs but also raise critical concerns regarding food safety and environmental sustainability. Genetically modified (GM) technology offers a promising solution of pest management by introducing insect resistance trait into plants. Unlike transgenic corn and soybean, transgenic cowpea conferring insect resistance has not been fully explored and utilized. RESULTS: In this study, a Cry1Ab-Vip3A fusion gene, C1V3, was successfully introduced into the cowpea genome. Transgenic cowpea lines with resistance to broad-spectrum lepidopteran pests were obtained by an improved transformation method using glyphosate as selection. A promising line, CAP5, selected from 37 transgenic events, was characterized as a single T-DNA copy event with single insertion site at the Chr5 of cowpea genome. Comprehensive evaluation for insect resistance and herbicide tolerance indicated that CAP5 was highly resistant to BAW, LPB and TCW and exhibited strong tolerance to glyphosate, underscoring its application potential as an insect-resistant and herbicide-tolerant cowpea event. CONCLUSION: Transgenic cowpea line CAP5 expressing Cry1Ab-Vip3A fusion protein and CP4-EPSPS is highly resistant to BAW, TCW and LPB, and strongly tolerant to glyphosate. © 2025 Society of Chemical Industry.