title: Spatio-temporal appearance of α-amylase and limit dextrinase in barley aleurone layer in response to gibberellic acid, abscisic acid and salicylic acid.
abstract: BACKGROUND
  Cereal seed germination involves mobilization of storage reserves in the starchy endosperm to support seedling growth. In response to gibberellin produced by the embryo the aleurone layer synthesizes hydrolases that are secreted to the endosperm for degradation of storage products. In this study analysis of intracellular protein accumulation and release from barley aleurone layers is presented for the important enzymes in starch degradation: α-amylase and limit dextrinase (LD).
  
  
  RESULTS
  Proteins were visualized by immunoblotting in aleurone layers and culture supernatants from dissected aleurone layers incubated up to 72 h with either gibberellic acid (GA), abscisic acid (ABA) or salicylic acid (SA). The results show that α-amylase is secreted from aleurone layer treated with GA soon after synthesis but the release of LD to culture supernatants was significantly delayed and coincided with a general loss of proteins from aleurone layers.
  
  
  CONCLUSIONS
  Release of LD was found to differ from that of amylase and was suggested to depend on programmed cell death (PCD). Despite detection of intracellular amylase in untreated aleurone layers or aleurone layers treated with ABA or SA, α-amylase was not released from these samples. Nevertheless, the release of α-amylase was observed from aleurone layers treated with GA+ABA or GA+SA.
authors.affiliation: Department of Agricultural Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
authors.forename: Azar
authors.initials: A
authors.lastname: Shahpiri
authors.forename: Nasim
authors.initials: N
authors.lastname: Talaei
authors.forename: Christine
authors.initials: C
authors.lastname: Finnie
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D056625:Endosperm / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology*; D005875:Gibberellins / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000032:analysis* / Q000378:metabolism; D001467:Hordeum / Q000201:enzymology* / Q000648:ultrastructure; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000032:analysis; D020156:Salicylic Acid / Q000494:pharmacology*; D000516:alpha-Amylases / Q000032:analysis* / Q000378:metabolism
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D000040:Abscisic Acid; C007842:gibberellic acid; D006026:Glycoside Hydrolases; D000516:alpha-Amylases; C100181:pullulanase; D020156:Salicylic Acid
keywords: aleurone layer; appearance patterns; barley; limit dextrinase; plant hormones; α-amylase