SERK1 receptor-like kinase regulates organ separation in Arabidopsis flowers

• Published in: The Plant journal : for cell and molecular biology Vol. 62; no. 5; pp. 817 - 828
• Main Authors: Lewis, Michael W, Leslie, Michelle E, Fulcher, Emilee H, Darnielle, Lalitree, Healy, Patrick N, Youn, Ji-Young, Liljegren, Sarah J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-06-2010; Blackwell Publishing Ltd; Blackwell
• Subjects: abscission; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; ARF-GAP; Biological and medical sciences; Botany; Cell physiology; Cell receptors; Cell structures and functions; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Chromosome Mapping; flower development; flowering; Flowers & plants; Flowers - growth & development; Flowers - ultrastructure; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genotype & phenotype; Golgi Apparatus - metabolism; Kinases; membrane trafficking; Microscopy, Electron, Transmission; Miscellaneous; Molecular and cellular biology; Mutation; NEVERSHED; Phenotype; Plant physiology and development; Protein Kinases - genetics; Protein Kinases - metabolism; receptor-like kinase; Senescence and abscission; Vegetative apparatus, growth and morphogenesis. Senescence; Flower; Separation; receptor-like kinase; Enzyme; Transferases; NEVERSHED; ARF-GAP; Abscission; Arabidopsis thaliana; Regulation(control); Cruciferae; Kinase; Dicotyledones; Angiospermae; Development; Membrane; flower development; Spermatophyta; membrane trafficking; Tumor suppressor gene; Organ; Biological receptor
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313x.2010.04194.x

Through a sensitized screen for novel components of pathways regulating organ separation in Arabidopsis flowers, we have found that the leucine-rich repeat receptor-like kinase SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 (SERK1) acts as a negative regulator of abscission. Mutations in SERK1 dominantly rescue abscission in flowers without functional NEVERSHED (NEV), an ADP-ribosylation factor GTPase-activating protein required for floral organ shedding. We previously reported that the organization of the Golgi apparatus and location of the trans-Golgi network (TGN) are altered in nev mutant flowers. Disruption of SERK1 restores Golgi structure and the close association of the TGN in nev flowers, suggesting that defects in these organelles may be responsible for the block in abscission. We have also found that the abscission zones of nev serk1 flowers are enlarged compared to wild-type. A similar phenotype was previously observed in plants constitutively expressing a putative ligand required for organ separation, INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), suggesting that signalling through IDA and its proposed receptors, HAESA and HAESA-LIKE2, may be deregulated in nev serk1 abscission zone cells. Our studies indicate that in addition to its previously characterized roles in stamen development and brassinosteroid perception, SERK1 plays a unique role in modulating the loss of cell adhesion that occurs during organ abscission.