title: Identification of ICE1 as a negative regulator of ABA-dependent pathways in seeds and seedlings of Arabidopsis.
abstract: Inducer of CBF expression 1 (ICE1) mediates the cold stress signal via an abscisic acid (ABA)-independent pathway. A possible role of ICE1 in ABA-dependent pathways was examined in this study. Seedling growth was severely reduced in a T-DNA insertion mutant of ICE1, ice1-2, when grown on 1/2 MS medium lacking sugars, but was restored to wild-type (WT) levels by supplementation with 56 mM glucose. In addition to this sugar-dependent phenotype, germination and establishment of ice1-2 were more sensitive to high glucose concentrations than in the WT. Hypersensitivity to ABA was also observed in ice1-2, suggesting its sensitivity to glucose might be mediated through the ABA signaling pathway. Glucose and ABA induced much higher expression of two genes related to ABA signal transduction, ABA-INSENSITIVE 3 (ABI3) and ABA-INSENSITIVE 4 (ABI4), in ice1-2 than in the WT during establishment. In summary, in addition to its known roles in regulating cold responses, stomatal development, and endosperm breakdown, ICE1 is a negative regulator of ABA-dependent responses.
authors.affiliation: Department of Biochemical Science and Technology, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Ching-Hsing
authors.initials: CH
authors.lastname: Liang
authors.forename: Chien-Chih
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D018525:Germination; D005947:Glucose / Q000378:metabolism; D016254:Mutagenesis, Insertional; D010937:Plant Growth Regulators / Q000378:metabolism*; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; C510502:ICE1 protein, Arabidopsis; D010937:Plant Growth Regulators; D014157:Transcription Factors; D000040:Abscisic Acid; D005947:Glucose