title: Analysis of embryonic proteome modulation by GA and ABA from germinating rice seeds.
abstract: The phytohormones gibberellic acid (GA) and abscisic acid (ABA) play essential and often antagonistic roles in regulating plant growth, development, and stress responses. Using a proteomics-based approach, we examined the role of GA and ABA in the modulation of protein expression levels during seed germination. Rice seeds were treated with GA (200 microM), ABA (10 microM), ABA followed by GA, GA followed by ABA, and water as a control and then incubated for 3 days. The embryo was dissected from germinated seeds, and proteins were subjected to 2-DE. Approximately, 665 total protein spots were resolved in the 2-D gels. Among them, 16 proteins notably modulated by either GA or ABA were identified by MALDI-TOF MS. Northern analyses demonstrated that expression patterns of 13 of these 16 genes were consistent with those of the proteome analysis. Further examination of two proteins, rice isoflavone resuctase (OsIFR) and rice PR10 (OsPR10), using Western blot and immunolocalization, revealed that both are specifically expressed in the embryo but not in the endosperm and are dramatically downregulated by ABA.
authors.affiliation: Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju, Korea.
authors.forename: Sun Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kang
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wang
authors.forename: Sang Gon
authors.initials: SG
authors.lastname: Kim
authors.forename: Du Hyeon
authors.initials: du H
authors.lastname: Hwang
authors.forename: Kyu Young
authors.initials: KY
authors.lastname: Kang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D015152:Blotting, Northern; D015153:Blotting, Western; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000502:physiology; D005875:Gibberellins / Q000494:pharmacology*; D012275:Oryza / Q000187:drug effects / Q000196:embryology*; D010940:Plant Proteins / Q000187:drug effects* / Q000378:metabolism*; D020543:Proteome / Q000187:drug effects*; D012639:Seeds / Q000187:drug effects* / Q000502:physiology
chemical_list: D005875:Gibberellins; D010940:Plant Proteins; D020543:Proteome; D000040:Abscisic Acid; C007842:gibberellic acid