title: CIPK6, a CBL-interacting protein kinase is required for development and salt tolerance in plants.
abstract: Calcineurin B-like proteins (CBL) and CBL-interacting protein kinases (CIPK) mediate plant responses to a variety of external stresses. Here we report that Arabidopsis CIPK6 is also required for the growth and development of plants. Phenotype of tobacco plants ectopically expressing a homologous gene (CaCIPK6) from the leguminous plant chickpea (Cicer arietinum) indicated its functional conservation. A lesion inAtCIPK6 significantly reduced shoot-to-root and root basipetal auxin transport, and the plants exhibited developmental defects such as fused cotyledons, swollen hypocotyls and compromised lateral root formation, in conjunction with reduced expression of a number of genes involved in auxin transport and abiotic stress response. The Arabidopsis mutant was more sensitive to salt stress compared to wild-type, while overexpression of a constitutively active mutant of CaCIPK6 promoted salt tolerance in transgenic tobacco. Furthermore, tobacco seedlings expressing the constitutively active mutant of CaCIPK6 showed a developed root system, increased basipetal auxin transport and hypersensitivity to auxin. Our results provide evidence for involvement of a CIPK in auxin transport and consequently in root development, as well as in the salt-stress response, by regulating the expression of genes.
authors.affiliation: National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Vineeta
authors.initials: V
authors.lastname: Tripathi
authors.forename: Boominathan
authors.initials: B
authors.lastname: Parasuraman
authors.forename: Ashverya
authors.initials: A
authors.lastname: Laxmi
authors.forename: Debasis
authors.initials: D
authors.lastname: Chattopadhyay
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D055049:Salt Tolerance / Q000235:genetics*; D016415:Sequence Alignment; D013312:Stress, Physiological; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C562040:CIPK6 protein, Arabidopsis; D011494:Protein Kinases