title: ZHOUPI controls embryonic cuticle formation via a signalling pathway involving the subtilisin protease ABNORMAL LEAF-SHAPE1 and the receptor kinases GASSHO1 and GASSHO2.
abstract: Seed production in angiosperms requires tight coordination of the development of the embryo and the endosperm. The endosperm-specific transcription factor ZHOUPI has previously been shown to play a key role in this process, by regulating both endosperm breakdown and the formation of the embryonic cuticle. To what extent these processes are functionally linked is, however, unclear. In order to address this issue we have concentrated on the subtilisin-like serine protease encoding gene ABNORMAL LEAF-SHAPE1. Expression of ABNORMAL LEAF-SHAPE1 is endosperm specific, and dramatically decreased in zhoupi mutants. We show that, although ABNORMAL LEAF-SHAPE1 is required for normal embryonic cuticle formation, it plays no role in regulating endosperm breakdown. Furthermore, we show that re-introducing ABNORMAL LEAF-SHAPE1 expression in the endosperm of zhoupi mutants partially rescues embryonic cuticle formation without rescuing their persistent endosperm phenotype. Thus, we conclude that ALE1 can normalize cuticle formation in the absence of endosperm breakdown, and that ZHOUPI thus controls two genetically separable developmental processes. Finally, our genetic study shows that ZHOUPI and ABNORMAL LEAF-SHAPE1 promotes formation of embryonic cuticle via a pathway involving embryonically expressed receptor kinases GASSHO1 and GASSHO2. We therefore provide a molecular framework of inter-tissue communication for embryo-specific cuticle formation during embryogenesis.
authors: Institute of Molecular Plant Sciences, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JH, UK.
authors: Qian
authors: Q
authors: Xing
authors: Audrey
authors: A
authors: Creff
authors: Andrew
authors: A
authors: Waters
authors: Hirokazu
authors: H
authors: Tanaka
authors: Justin
authors: J
authors: Goodrich
authors: Gwyneth C
authors: GC
authors: Ingram
mesh_terms: D017360:Arabidopsis / Q000196:embryology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D005838:Genotype; D006652:Histological Techniques; D011494:Protein Kinases / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000166:cytology / Q000196:embryology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014048:Tolonium Chloride
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D017931:DNA Primers; D011494:Protein Kinases; D012697:Serine Endopeptidases; D014048:Tolonium Chloride; C532182:RETARDED GROWTH OF EMBRYO1 protein, Arabidopsis; C528620:GASSHO1 protein, Arabidopsis; C528621:GASSHO2 protein, Arabidopsis; C443900:ALE1 protein, Arabidopsis