Ectopic expression of an Old Yellow Enzyme (OYE3) gene from Saccharomyces cerevisiae increases the tolerance and phytoremediation of 2-nitroaniline in rice

2-nitroaniline (2 -NA) is an environmental pollutant and has been extensively used as intermediates in organic synthesis. The presence of 2 -NA in the environment is not only harmful for aquatic life but also mutagenic for human beings. In this study, we constructed transgenic rice expressing an Old Yellow Enzyme gene, ScOYE3 , from Saccharomyces cerevisiae. The ScOYE3 transgenic plants were comprehensively investigated for their biochemical responses to 2 -NA treatment and their 2 -NA phytoremediation capabilities. Our results showed that the rice seedlings exposed to 2 -NA stress, showed growth inhibition and biomass reduction. However, the transgenic plants exhibited strong tolerance to 2 -NA stress compared to wild -type plants. Ectopic expression of ScOYE3 could effectively protect transgenic plants against 2 -NA damage, which resulted in less reactive oxygen species accumulation in transgenic plants than that in wild -type plants. Our phytoremediation assay revealed that transgenic plants could eliminate more 2 -NA from the medium than wild -type plants. Moreover, omics analysis was performed in order to get a deeper insight into the mechanism of ScOYE3-mediated 2 -NA transformation in rice. Altogether, the function of ScOYE3 during 2 -NA detoxification was characterized for the first time, which serves as strong theoretical support for the phytoremediation potential of 2 -NA by Old Yellow Enzyme genes.