title: Constitutive over-expression of rice ClpD1 protein enhances tolerance to salt and desiccation stresses in transgenic Arabidopsis plants.
abstract: Caseinolytic proteases (Clps) perform the important role of removing protein aggregates from cells, which can otherwise prove to be highly toxic. ClpD system is a two-component protease complex composed of a regulatory ATPase module ClpD and a proteolytic component ClpP. Under desiccation stress condition, rice ClpD1 (OsClpD1) gene encoding for the regulatory subunit, was represented by four variant transcripts differing mainly in the expanse of their N-terminal amino acids. These transcripts were expressed in a differential manner in response to salt, mannitol and polyethylene glycol stresses in rice. Purified OsClpD1.3 protein exhibited intrinsic chaperone activity, shown using citrate synthase as substrate. Arabidopsis (Col-0) plants over-expressing OsClpD1.3 open reading frame downstream to CaMV35S promoter (ClpD1.3 plants) showed higher tolerance to salt and desiccation stresses as compared to wild type plants. ClpD1.3 seedlings also showed enhanced growth during the early stages of seed germination under unstressed, control conditions. The free proline levels and starch breakdown activities were higher in the ClpD1.3 seedlings as compared to the wild type Arabidopsis seedlings. It thus emerges that increasing the potential of ClpD1 chaperoning activity may be of advantage in protection against abiotic stresses.
authors.affiliation: Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India.
authors.forename: Ratnesh Chandra
authors.initials: RC
authors.lastname: Mishra
authors.affiliation: Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India.
authors.lastname: Richa
authors.affiliation: Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India. Electronic address: anil.anilgrover@gmail.com.
authors.forename: Anil
authors.initials: A
authors.lastname: Grover
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D003890:Desiccation; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D055049:Salt Tolerance / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride
keywords: Arabidopsis thaliana; Chaperone; ClpD1 ATPase; Oryza sativa; Osmotic stress; Salt stress