Identification, characterization and expression of rice (Oryza sativa) acetyltransferase genes exposed to realistic environmental contamination of mesotrione and fomesafen.

The plant acetyltransferases (ACEs) belong to a super family of proteins that contribute to secondary metabolisms and involve various abiotic and biotic stress responses. However, how rice ACEs respond to toxic agrochemicals is largely unknown. This study demonstrates that 86 and 83 genes coding ACEs in the transcriptome profiling were expressed under mesotrione (MTR) and fomesafen (FSA) exposure, respectively. Of these, 18 and 8 ACE differentially expressed genes (DEGs) were identified in MTR- and FSA-exposed rice transcriptome datasets. Some of the ACE genes were validated by quantitative RT-PCR analysis. Analysis of biochemical properties of ACEs revealed that many genes have various cis-elements and structural domain which may cope with a variety of biotic and abiotic stress responses and detoxification of xenobiotics. Moreover, the ACE activities in rice were induced under MTR and FSA exposure and reached out to the highest value at the 0.1 mg L. The ACE activities in the MTR and FSA treated roots were 2.6 and 3.5 fold over the control and those in shoots with MTR and FSA were 4.0 and 26.1 fold over the control, respectively. These results indicate that the ACE-coding genes can respond to the MTR and FSA stress by increasing their transcriptional level, along with the enhanced specific ACE protein activities in rice tissues.