title: miR395 is involved in detoxification of cadmium in Brassica napus.
abstract: The toxic metal cadmium (Cd) constitutes one of the major inorganic contaminants in environments. microRNAs (miRNAs) are a class of endogenous non-coding small RNAs. miR395 is conserved and regulates sulfate assimilation and distribution in higher plants, but whether it is involved in detoxification of Cd in plants has not been described. In this study, transgenic rapeseed (Brassica napus) over-expressing miR395 was identified under Cd stress. miR395-over-expressing plants showed a lower degree of Cd-induced oxidative stress than wild type. By contrast, chlorophyll, glutathione and non-protein thiols contents were higher in the transformants than wild type. Determination of growth response showed that 35S::MIR395 plants accumulated higher levels of biomass and sulfur than wild type under Cd exposure. miR395 transgenic plants had higher levels of Cd in plants, particularly at the high supply of Cd in the medium, but they tended to repress Cd translocation from roots to shoots. Simultaneously, expression of metal-tolerance genes such as BnPCS1, BnHO1 and Sultr1;1 was up-regulated under Cd stress, and the expression of the genes was more pronounced in 35S::MIR395 plants than in wild type. These results suggest that miR395 would be involved in detoxification of Cd in B. napus.
authors: Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China.
authors: Liu Wei
authors: LW
authors: Zhang
authors: Jian Bo
authors: JB
authors: Song
authors: Xia Xia
authors: XX
authors: Shu
authors: Yun
authors: Y
authors: Zhang
authors: Zhi Min
authors: ZM
authors: Yang
mesh_terms: D001692:Biological Transport; D018533:Biomass; D029688:Brassica napus / Q000187:drug effects* / Q000235:genetics*; D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification*; D002734:Chlorophyll / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000737:chemistry; D008658:Inactivation, Metabolic / Q000235:genetics*; D008670:Metals / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry; D035683:MicroRNAs / Q000378:metabolism* / Q000502:physiology; D018384:Oxidative Stress; D012639:Seeds / Q000378:metabolism; D013431:Sulfates / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry
chemical_list: D008670:Metals; D019216:Metals, Heavy; D035683:MicroRNAs; D013431:Sulfates; D013438:Sulfhydryl Compounds; D002104:Cadmium; D002734:Chlorophyll; D013455:Sulfur; D005978:Glutathione