Stress signaling through Ca2+/calmodulin-dependent protein phosphatase calcineurin mediates salt adaptation in plants

• Published in: Proceedings of the National Academy of Sciences - PNAS 1998-08, Vol.95 (16), p.9681-9686
• Main Authors: Pardo, J.M. (Consejo Superior de Investigaciones Cientificas, Sevilla, Spain.), Reddy, M.P, Yang, S, Maggio, A, Huh, G.H, Matsumoto, T, Coca, M.A, Paino-D'Urzo, M, Koiwa, H, Yun, D.J
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; ADN; ARN MENSAJERO; ARN MESSAGER; Base Sequence; Biological Sciences; Calcineurin - metabolism; Calcium; CHLORURE DE SODIUM; CLORURO SODICO; COMPLEMENTARY DNA; CRECIMIENTO; CROISSANCE; DNA; DNA Primers; ESTERASAS; ESTERASE; ESTERASES; ESTRES; EXPRESION GENICA; EXPRESSION DES GENES; Flowers & plants; GENE; GENE EXPRESSION; Gene expression regulation; GENE TRANSFER; GENES; GENETIC INHERITANCE; GENETIC TRANSFORMATION; GRAFTING; GREFFAGE; GREFFON; GROWTH; HEREDITE; HERENCIA GENETICA; Hydroponics; INJERTO; INJERTO DE PUA; MESSENGER RNA; NICOTIANA TABACUM; Oxidative Stress; Phosphatases; Phosphates; PHOSPHOPROTEIN PHOSPHATASE; Plant Physiological Phenomena; Plant roots; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants; Proteins; RACINE; Rafts; RAICES; ROOTS; SACCHAROMYCES CEREVISIAE; SALINIDAD; SALINITE; SALINITY; Salt; SALT TOLERANCE; SCIONS; Seedlings; SEGREGACION; SEGREGATION; Signal Transduction; SODIUM CHLORIDE; Space life sciences; STEMS; STRESS; STRUCTURAL GENES; Table salt; TALLO; TIGE; TOLERANCE AU SEL; TOLERANCIA A LA SAL; TRANSFERENCIA DE GENES; TRANSFERT DE GENE; TRANSFORMACION GENETICA; TRANSFORMATION GENETIQUE; TRANSGENIC PLANTS; Yeasts
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.16.9681

Calcineurin (CaN) is a Ca(2+)- and calmodulin-dependent protein phosphatase (PP2B) that, in yeast, is an integral intermediate of a salt-stress signal transduction pathway that effects NaCl tolerance through the regulation of Na(+) influx and efflux. A truncated form of the catalytic subunit and the regulatory subunit of yeast CaN were coexpressed in transgenic tobacco plants to reconstitute a constitutively activated phosphatase in vivo. Several different transgenic lines that expressed activated CaN also exhibited substantial NaCl tolerance, and this trait was linked to the genetic inheritance of the CaN transgenes. Enhanced capacity of plants expressing CaN to survive NaCl shock was similar when evaluation was conducted on seedlings in tissue culture raft vessels or plants in hydroponic culture that were transpiring actively. Root growth was less perturbed than shoot growth by NaCl in plants expressing CaN. Also, NaCl stress survival of control shoots was enhanced substantially when grafted onto roots of plants expressing CaN, further implicating a significant function of the phosphatase in the preservation of root integrity during salt shock. Together, these results indicate that in plants, like in yeast, a Ca(2+)- and calmodulin-dependent CaN signal pathway regulates determinants of salt tolerance required for stress adaptation. Furthermore, modulation of this pathway by expression of an activated regulatory intermediate substantially enhanced salt tolerance