title: GmSAL1 hydrolyzes inositol-1,4,5-trisphosphate and regulates stomatal closure in detached leaves and ion compartmentalization in plant cells.
abstract: Inositol polyphosphatases are important regulators since they control the catabolism of phosphoinositol derivatives, which are often signaling molecules for cellular processes. Here we report on the characterization of one of their members in soybean, GmSAL1. In contrast to the substrate specificity of its Arabidopsis homologues (AtSAL1 and AtSAL2), GmSAL1 only hydrolyzes inositol-1,4,5-trisphosphate (IP3) but not inositol-1,3,4-trisphosphate or inositol-1,4-bisphosphate.The ectopic expression of GmSAL1 in transgenic Arabidopsis thaliana led to a reduction in IP3 signals, which was inferred from the reduction in the cytoplasmic signals of the in vivo biomarker pleckstrin homology domain-green florescent protein fusion protein and the suppression of abscisic acid-induced stomatal closure. At the cellular level, the ectopic expression of GmSAL1 in transgenic BY-2 cells enhanced vacuolar Na(+) compartmentalization and therefore could partially alleviate salinity stress.
authors.affiliation: Center for Soybean Research, State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR.
authors.forename: Yee-Shan
authors.initials: YS
authors.lastname: Ku
authors.forename: Nicolas Siu-Chung
authors.initials: NS
authors.lastname: Koo
authors.forename: Francisca Wing-Yen
authors.initials: FW
authors.lastname: Li
authors.forename: Man-Wah
authors.initials: MW
authors.lastname: Li
authors.forename: Hongmei
authors.initials: H
authors.lastname: Wang
authors.forename: Sau-Na
authors.initials: SN
authors.lastname: Tsai
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.forename: Boon Leong
authors.initials: BL
authors.lastname: Lim
authors.forename: Wing-Hung
authors.initials: WH
authors.lastname: Ko
authors.forename: Hon-Ming
authors.initials: HM
authors.lastname: Lam
mesh_terms: D000040:Abscisic Acid / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D007295:Inositol Phosphates / Q000235:genetics / Q000378:metabolism*; D009708:Nucleotidases / Q000235:genetics / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases; D054046:Plant Stomata / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D054712:Salinity; D017385:Sequence Homology; D015398:Signal Transduction / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology* / Q000235:genetics; D013312:Stress, Physiological / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D007295:Inositol Phosphates; C116606:inositol-1,2,4,5-tetrakisphosphate; D000040:Abscisic Acid; D012964:Sodium; D009708:Nucleotidases; D010744:Phosphoric Monoester Hydrolases; C053087:inositol-1,4-bisphosphate 1-phosphatase