title: Ectopic overexpression of vacuolar and apoplastic Catharanthus roseus peroxidases confers differential tolerance to salt and dehydration stress in transgenic tobacco.
abstract: CrPrx and CrPrx1 are class III peroxidases previously cloned and characterized from Catharanthus roseus. CrPrx is known to be apoplastic in nature, while CrPrx1 is targeted to vacuoles. In order to study their role in planta, these two peroxidases were expressed in Nicotiana tabacum. The transformed plants exhibited increased peroxidase activity. Increased oxidative stress tolerance was also observed in transgenics when treated with H(2)O(2) under strong light conditions. However, differential tolerance to salt and dehydration stress was observed during germination of T1 transgenic seeds. Under these stresses, the seed germination of CrPrx-transformed plants and wild-type plants was clearly suppressed, whereas CrPrx1 transgenic lines showed improved germination. CrPrx-transformed lines exhibited better cold tolerance than CrPrx1-transformed lines. These results indicate that vacuolar peroxidase plays an important role in salt and dehydration stress over cell wall-targeted peroxidase, while cell wall-targeted peroxidase renders cold stress tolerance.
authors.affiliation: National Institute of Plant Genome Research, 10531, Aruna Asaf Ali Road, New Delhi, 110 067, India.
authors.forename: Santosh
authors.initials: S
authors.lastname: Kumar
authors.forename: Monika
authors.initials: M
authors.lastname: Jaggi
authors.forename: Alok Krishna
authors.initials: AK
authors.lastname: Sinha
mesh_terms: D030008:Catharanthus / Q000201:enzymology*; D003681:Dehydration; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D012965:Sodium Chloride / Q000633:toxicity*; D014026:Nicotiana / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D014617:Vacuoles / Q000201:enzymology*
chemical_list: D012965:Sodium Chloride; D010544:Peroxidases