Proteomics analysis identified a DRT protein involved in arsenic resistance in Populus.

KEY MESSAGE: A DRT protein was identified and proved to be involved in the poplar arsenic resistance through comparative proteomics analysis between arsenic sensitive and resistant cultivars. Arsenic pollution in soil has been a serious problem all over the world. It is very important to dissect plants arsenic stress-response mechanisms in phytoremediation. In this study, arsenate-tolerant Populus deltoides cv. 'zhonglin 2025' and arsenate-sensitive Populus × euramericana cv. 'I-45/51' were screened from 10 poplar varieties. Systematic comparisons between these two cultivars demonstrated that 'zhonglin 2025' exhibited slighter morphological and structural injury, lower ROS and MDA accumulation, and higher photosynthesis and ROS scavenging ability under arsenate stress, compared with 'I-45/51'. Through comparative proteomics analysis, we detected that most of the identified arsenate-responsive proteins were stress and defense related. Among these proteins, PdDRT102 was found to be only highly induced in 'zhonglin 2025' under arsenate stress. Heterologous over-expression of PdDRT102 in Arabidopsis conferred to enhanced tolerance to arsenate and sodium chloride. PdDRT102 localizes to the plasma membrane and the nucleus in Arabidopsis. Interestingly, the remarkably increased fluorescence protein signals in the nucleus were found during arsenate stress. Together, these results not only provided an overall understanding on poplar response to arsenate stress, but also revealed that DRT102 protein might involve in protecting poplar against this stress.