Abstract
The widespread use of isoproturon [IPU] can lead to severe environmental pollution and threats to environmental functions. In this study, the PDMAB IPU bacterial n-demethylase gene was transported and expressed in fat pea chloroplast [Glycine Max L. 'Zhonghuang13']. Transgenic fat bean pods showed significant resistance to PPU and demethylated PPU to the phytotoxic 3-[4 - isopropylphenyl]-1-methylurea [MDIPU] metabolite in vivo. Transgenic fat bean pods removed 98% and 84% MPU from water and soil in 5 and 14 days respectively, accumulating fewer MPU in plant tissues compared to wild type [WT]. MPs showed higher rates of symbiotic nitrogen fixation in transgenic fat peas under stress [total biomass o f nodules and higher nitrogenase activity] and a more stable community of rhizosphere bacteria than WT. However, intensive use and accumulation of toxic herbicides can negatively affect the symbiosis of legumes. Thirty different herbicides and environmental pollutants have affected signaling between plants and rhizobias, delayed node formation, and reduced biological nitrogen fixation in vitro [Fox et al., 2007]. This study developed a transgenic [TS] oil bean that is capable of effectively removing PPU from the growing environment and restoring the high symbiotic ability to fix nitrogen under PPU stress, and provides new insight into the interaction between rhizospheric microorganisms and legumes under herbicidal stress.