Expression of CYP76C6 Facilitates Isoproturon Metabolism and Detoxification in Rice

: Agricultural chemical residues in farmland and crops is one of the serious public issues that constantly threatens crop production, food security, and human health. Understanding their decay mechanism in crops for accelerating their degradative metabolism is important. In this study, a rice uncharacterized cytochrome P450 gene encoding CYP76C6 was functionally identified in rice exposed to isoproturon (IPU). To verify the role of CYP76C6 in rice resistance to IPU toxicity, CYP76C6 overexpression (OEs) and knockout mutant rice by CRISPR/Cas9 were generated through genetic transformation and gene-editing technologies. Assessment of growth and physiological responses revealed that the growth of OE lines was improved, the IPU-induced cellular damage was attenuated, and IPU accumulation was significantly repressed, whereas the Cas9 lines displayed a contrasting phenotype compared to the wild-type. Both relative contents of IPU metabolites and conjugates in OE lines were reduced and those in Cas9 line were increased, suggesting that CYP76C6 plays a critical role in IPU degradation. Our study unveils a new regulator, together with its mechanism for IPU decay in rice crops, which will be used in reality to reduce environmental risks in food safety and human health.

Automated summary

In this study, a new cytochrome P450 gene, CYP76C6, was discovered in rice, which plays a critical role in accelerating the degradation of isoproturon (IPU). Overexpression of CYP76C6 improved rice growth, attenuated IPU-induced cellular damage, and repressed IPU accumulation. The study provides insights into the mechanism of IPU decay in rice crops and its potential application in reducing environmental risks and ensuring food safety and human health.