title: Characterization of an Arabidopsis cadmium-resistant mutant cdr3-1D reveals a link between heavy metal resistance as well as seed development and flowering.
abstract: A lot of studies have identified many key genes involved in heavy metal detoxification and tolerance in plants; however, our understanding of its molecular mechanisms is far from complete. To gain insight into the regulatory mechanisms for heavy metal detoxification and tolerance, we performed a mutant screen for identifying Arabidopsis (Arabidopsis thaliana) cadmium (Cd)-resistant mutants. A Cd-resistant mutant cdr3-1D (c a d mium-r esistant) was isolated because of its increased root growth and fresh weight in Cd stress, and genetic analysis showed that cdr3-1D is a single dominant nuclear mutation. Compared with the wild type, the cdr3-1D mutant was more resistant to heavy metals Cd, Pb, and copper as well as hydrogen peroxide. Moreover, we also observed that seeds of the cdr3-1D mutant were larger than those of wild type, and that cdr3-1D displayed early flowering compared with wild type. A lower Cd/Pb content was detected in cdr3-1D plants than in wild-type plants when subjected to Cd/Pb treatment, which was associated, at least in part, with increase of expression of AtPDR8/AtPDR12, a pump excluding Cd/Pb and/or Cd/Pb-containing toxic compounds from the cytoplasm, respectively. In addition, enhanced Cd/Pb resistance of the cdr3-1D mutant was partially glutathione (GSH) dependent, which was related to increase of expression of GSH1 gene involved in GSH synthesis and consequently increased GSH content. Taken together, our results provide genetic evidence indicating that CDR3 is involved in the regulation of heavy metal resistance as well as seed development and flowering.
authors.affiliation: School of Biotechnology and Food Engineering Hefei University of Technology, No. 193 Tunxi Road, Hefei, 230009, Anhui, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Zong
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.forename: Jiajia
authors.initials: J
authors.lastname: Sun
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Ren
authors.forename: Zehua
authors.initials: Z
authors.lastname: Sun
authors.forename: Chen
authors.initials: C
authors.lastname: Wen
authors.forename: Xueping
authors.initials: X
authors.lastname: Chen
authors.forename: Shuqing
authors.initials: S
authors.lastname: Cao
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D003300:Copper / Q000633:toxicity; D035264:Flowers / Q000187:drug effects / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007854:Lead / Q000378:metabolism / Q000633:toxicity; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; D002104:Cadmium; D007854:Lead; D019328:Buthionine Sulfoximine; D003300:Copper; D006861:Hydrogen Peroxide; D005978:Glutathione