OsARM1, an R2R3 MYB Transcription Factor, Is Involved in Regulation of the Response to Arsenic Stress in Rice

• DOI: 10.3389/fpls.2017.01868
• Publication Date: 2017-10-30T07:46:30Z
• Authors: Feng-Zhu Wang; Mo-Xian Chen; Lu-Jun Yu; Li-Juan Xie; Li-Bing Yuan; Hua Qi; Ming Xiao; Wuxiu Guo; Zhe Chen; Keke Yi; Jianhua Zhang; Rongliang Qiu; Wensheng Shu; Shi Xiao; Qin-Fang Chen
• Keywords: MYB

Bioaccumulation of arsenic (As) in rice (Oryza sativa) increases human exposure to this toxic, carcinogenic element. Recent studies identified several As transporters, but the regulation these transporters remains unclear. Here, we show that R2R3 MYB transcription factor OsARM1 (ARSENITE-RESPONSIVE MYB1) regulates As-associated genes. Treatment with As(III) induced transcript accumulation and an OsARM1-GFP fusion localized nucleus. Histochemical analysis OsARM1pro::GUS lines indicated was expressed phloem vascular bundles basal upper nodes. Knockout (OsARM1-KO CRISPR/Cas9-generated mutants) improved tolerance overexpression (OsARM1-OE lines) increased sensitivity As(III). Measurement As(III)-treated plants showed under low conditions (2 μM), more transported from roots shoots OsARM1-KOs. By contrast, accumulated OsARM1-OEs response high (25 μM). In particular, levels node I were significantly higher OsARM1-KOs, lower OsARM1-OEs, compared wild-type plants, implying is important for root-to-shoot translocation As. Moreover, OsLsi1, OsLsi2, OsLsi6, which encode key downregulated upregulated OsARM1-KOs wild type. Chromatin immunoprecipitation-quantitative PCR binds conserved MYB-binding sites promoters or genomic regions OsLsi6 rice. Our findings suggest has essential functions regulating uptake