Stress signaling through Ca2+/calmodulin-dependent protein phosphatase calcineurin mediates salt adaptation in plants
AUTOR(ES)
Pardo, José M.
FONTE
The National Academy of Sciences
RESUMO
Calcineurin (CaN) is a Ca2+- 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 Ca2+- 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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=21399Documentos Relacionados
- An ultrasensitive Ca2+/calmodulin-dependent protein kinase II-protein phosphatase 1 switch facilitates specificity in postsynaptic calcium signaling
- Regulatory interactions of calmodulin-binding proteins: phosphorylation of calcineurin by autophosphorylated Ca2+/calmodulin-dependent protein kinase II.
- The role of Ca2+/calmodulin-dependent protein kinase II and calcineurin in TNF-α-induced myocardial hypertrophy
- Multiple Ca2+/calmodulin-dependent protein kinase genes in a unicellular eukaryote.
- Autophosphorylation reversibly regulates the Ca2+/calmodulin-dependence of Ca2+/calmodulin-dependent protein kinase II.