Bermuda grass (Cynodon dactylon) is notoriously difficult to control with some commonly used herbicides. We cloned a cytochrome P450 gene from Bermuda grass, named P450-N-Z1, which was found to confer tolerance to multiple herbicides in transgenic Arabidopsis. These herbicides include: (1) acetolactate synthase (ALS) inhibitor herbicides nicosulfuron and penoxsulam; (2) p-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide mesotrione; (3) synthetic auxin herbicide dicamba; (4) photosynthesis inhibitor bentazon. We further generated transgenic soybean plants expressing P450-N-Z1, and found that these transgenic soybean plants gained robust tolerance to nicosulfuron, flazasulfuron, and 2,4-dichlorophenoxyacetic acid (2,4-D) in greenhouse assays. A field trial demonstrated that transgenic soybean is tolerant to flazasulfuron and 2,4-D at 4-fold and 2-fold the recommended rates, respectively. Furthermore, we also demonstrated that flazasulfuron and dicamba are much more rapidly degraded in vivo in the transgenic soybean than in non-transgenic soybean. Therefore, P450-N-Z1 may be utilized for engineering transgenic crops for herbicide tolerance.

Genetically modified (GM) crops tolerant to glyphosate have delivered significant economic benefits in farm management. However, the evolution of glyphosate resistance in weeds due to prolonged intensive use of glyphosate poses a serious threat to this weed management system. It is highly desirable in China to deploy dual herbicide-tolerant corn at the very beginning of GM corn release to delay the development of weed resistance to herbicides. Here, we report the creation and characterization of a herbicide-tolerant corn event SCB-29 that expresses both cp4 epsps and bar genes. This transgenic maize is tolerant to glyphosate up to 3600 g a.e. ha⁻¹ and glufosinate up to 3600 g a.i. ha⁻¹, which are quadruple the recommended rates for the two herbicides, respectively. SCB-29 is an event with only a single copy of T-DNA inserted into chromosome 10 of the maize genome. An event-specific PCR detection method was established and three generations of SCB-29 were detected by event-specific PCR suggesting that the transgenes are stably integrated into the maize genome. Analysis of the expression levels of the transgenes among plants of multiple generations by enzyme-linked immunosorbent assays suggested that the expressions are stable over different generations. Moreover, the major agronomic performances of SCB-29 appear to be similar to those of non-transgenic maize, suggesting that SCB-29 is not likely to have yield drag. Therefore, SCB-29 is an excellent herbicide-tolerant candidate to be developed into a commercial herbicide tolerance transgenic event.