title: Maternal ENODLs Are Required for Pollen Tube Reception in Arabidopsis.
abstract: During the angiosperm (flowering-plant) life cycle, double fertilization represents the hallmark between diploid and haploid generations [1]. The success of double fertilization largely depends on compatible communication between the male gametophyte (pollen tube) and the maternal tissues of the flower, culminating in precise pollen tube guidance to the female gametophyte (embryo sac) and its rupture to release sperm cells. Several important factors involved in the pollen tube reception have been identified recently [2-6], but the underlying signaling pathways are far from being understood. Here, we report that a group of female-specific small proteins, early nodulin-like proteins (ENODLs, or ENs), are required for pollen tube reception. ENs are featured with a plastocyanin-like (PCNL) domain, an arabinogalactan (AG) glycomodule, and a predicted glycosylphosphatidylinositol (GPI) anchor motif. We show that ENs are asymmetrically distributed at the plasma membrane of the synergid cells and accumulate at the filiform apparatus, where arriving pollen tubes communicate with the embryo sac. EN14 strongly and specifically interacts with the extracellular domain of the receptor-like kinase FERONIA, localized at the synergid cell surface and known to critically control pollen tube reception [6]. Wild-type pollen tubes failed to arrest growth and to rupture after entering the ovules of quintuple loss-of-function EN mutants, indicating a central role of ENs in male-female communication and pollen tube reception. Moreover, overexpression of EN15 by the endogenous promoter caused disturbed pollen tube guidance and reduced fertility. These data suggest that female-derived GPI-anchored ENODLs play an essential role in male-female communication and fertilization.
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Hou
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC.
authors.forename: Xinyang
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Cyprys
authors.affiliation: Waksman Institute of Microbiology, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bleckmann
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC.
authors.forename: Le
authors.initials: L
authors.lastname: Cai
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC.
authors.forename: Qingpei
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC.
authors.forename: Yu
authors.initials: Y
authors.lastname: Luo
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC; National Plant Gene Research Center (Beijing), Beijing 100101, PRC.
authors.forename: Hongya
authors.initials: H
authors.lastname: Gu
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresselhaus
authors.affiliation: Waksman Institute of Microbiology, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Dong
authors.affiliation: State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at School of Life Sciences, Peking University, Beijing 100871, PRC; National Plant Gene Research Center (Beijing), Beijing 100101, PRC. Electronic address: qulj@pku.edu.cn.
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Qu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009928:Organ Specificity; D010802:Phylogeny; D053205:Pollen Tube / Q000254:growth & development / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins