title: Salt Stress Perception and Plant Growth Regulators in the Halophyte Mesembryanthemum crystallinum.
abstract: We selected indicators of four different metabolic processes (Crassulacean acid metabolism [CAM], amino acid and nitrogen mobilization metabolism, osmoprotection, and plant defense mechanisms) to study the relationship between salt-stress-mediated and plant growth regulator (PGR)-induced responses in Mesembryanthemum crystallinum (ice plant). Nacl and PGRs (cytokinin and abscisic acid [ABA]) are efficient elicitors of the well-studied Nacl stress responses: induction of the CAM form of phosphoenolpyruvate carboxylase, proline pinitol accumulation, and the increase of an osmotin-like protein. NaCl and cytokinin are more effective than ABA in stimulating accumulation of proline and an osmotin-like protein before the plants are committed to flowering. The results are consistent with a plant defense-induction model, in which environmental stress and PGRs are distinct signals whose subsequent effects lead to overlapping responses, the magnitude of which depends on plant developmental status.
authors.affiliation: Department of Biochemistry, The University of Arizona, Tucson, Arizona 85721.
authors.forename: J. C.
authors.initials: JC
authors.lastname: Thomas
authors.forename: H. J.
authors.initials: HJ
authors.lastname: Bohnert