ORIGINAL ABSTRACT

Glyphosate has become a widely used broad-spectrum herbicide in agricultural fields due to its broad-spectrum efficacy, low toxicity, safety, and minimal of soil residue. However, glyphosate exerts an inactivating effect on both rice and paddy weeds, thereby limiting its large-scale application. Consequently, the development of glyphosate-tolerant rice varieties is essential for realizing the large-scale application of glyphosate in paddy fields for chemical weed control. In this study, we constructed the vector pC33-A15, which contained the glyphosate-resistant gene aroAA1501. This constructed vector was introduced into the rice variety ZH11 using the Agrobacterium-mediated transformation method, resulting in the generation of 37 transgenic plants. The glyphosate tolerance of the resulting genetically modified rice plants was evaluated through seed germination, hydroponic culture, and field spray tests to identify glyphosate-resistant plants. qRT-PCR analysis revealed that the aroAA1501 gene was successfully expressed in the genetically modified plants, with significantly increased expression levels in the leaves following glyphosate application. Western blot analysis further confirmed the successful expression of the aroAA1501 protein in the genetically modified plants. Additionally, shikimic acid content analysis conducted at various time points after glyphosate application demonstrated that the aroAA1501 protein effectively fulfilled the role of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), thereby maintaining normal metabolic activity. Our results indicated that the genetically modified rice developed in this study exhibited robust glyphosate tolerance, capable of withstanding glyphosate concentrations up to 8000 ppm. This study provides a valuable genetic resource for the development of glyphosate-tolerant genetically modified rice, offering a potential solution for efficient weed management in paddy fields.