The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and groundwater in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradation pathway of Pseudomonas sp. strain ADP, which is initiated by atzA, encoding atrazine chlorohydrolase. Here we explored the use of enhanced expression of a modified bacterial atrazine chlorohydrolase, p-AtzA, in transgenic grasses (tall fescue, perennial ryegrass, and switchgrass) and the legume alfalfa for the biodegradation of atrazine. Enhanced expression of p-AtzA was obtained by using combinations of the badnavirus promoter, the maize alcohol dehydrogenase first intron, and the maize ubiquitin promoter. For alfalfa, we used the first intron of the 5′-untranslated region tobacco alcohol dehydrogenase gene and the cassava vein mosaic virus promoter. Resistance of plants to atrazine in agar-based and hydroponic growth assays was correlated with in vivo levels of gene expression and atrazine degradation. The in planta expression of p-atzA enabled transgenic tall fescue to transform atrazine into hydroxyatrazine and other metabolites. Results of our studies highlight the potential use of transgenic plants for bioremediating atrazine in the environment.
Bibliographical noteFunding Information:
This study was supported, in part, from Grants from The Consortium for Plant Biotechnology Research, and Syngenta Crop Protection. We would like to thank Melinda Dornbusch for watering plants in the greenhouse and William Koskinen and Brian Barber for help with HPLC and LC–MS analyses. The mention of a trade-mark, proprietary product or vendor does not constitute a guarantee or warranty of the product by the United States Department of Agriculture (USDA), and does not imply its approval to the exclusion of other products and vendors that might also be suitable.
© 2014, Springer International Publishing Switzerland.
- Transgenic plants