title: Mutation in SUMO E3 ligase, SIZ1, disrupts the mature female gametophyte in Arabidopsis.
abstract: Female gametophyte is the multicellular haploid structure that can produce embryo and endosperm after fertilization, which has become an attractive model system for investigating molecular mechanisms in nuclei migration, cell specification, cell-to-cell communication and many other processes. Previous reports found that the small ubiquitin-like modifier (SUMO) E3 ligase, SIZ1, participated in many processes depending on particular target substrates and suppression of salicylic acid (SA) accumulation. Here, we report that SIZ1 mediates the reproductive process. SIZ1 showed enhanced expression in female organs, but was not detected in the anther or pollen. A defect in the siz1-2 maternal source resulted in reduced seed-set regardless of high SA concentration within the plant. Moreover, aniline blue staining and scanning electron microscopy revealed that funicular and micropylar pollen tube guidance was arrested in siz1-2 plants. Some of the embryo sacs of ovules in siz1-2 were also disrupted quickly after stage FG7. There was no significant affects of the siz1-2 mutation on expression of genes involved in female gametophyte development- or pollen tube guidance in ovaries. Together, our results suggest that SIZ1 sustains the stability and normal function of the mature female gametophyte which is necessary for pollen tube guidance.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ling
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zhang
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Huaiqing
authors.initials: H
authors.lastname: Hao
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Ray A
authors.initials: RA
authors.lastname: Bressan
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hasegawa
authors.forename: Jing Bo
authors.initials: JB
authors.lastname: Jin
authors.forename: Jinxing
authors.initials: J
authors.lastname: Lin
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000201:enzymology* / Q000235:genetics* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics*; D056130:Gametogenesis, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006720:Homozygote; D008025:Ligases / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D056771:Ovule / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development*; D010641:Phenotype; D053205:Pollen Tube / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D012639:Seeds / Q000196:embryology / Q000648:ultrastructure; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D049452:Green Fluorescent Proteins; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; C502552:SIZ1 protein, Arabidopsis