title: Fertilization recovery system is dependent on the number of pollen grains for efficient reproduction in plants.
abstract: For over a century, plant fertilization has been thought to depend on the fertility of a single pollen tube. However, we reported recently a "fertilization recovery system" in flowering plants that actively rescues failed fertilization of a defective mutant pollen tube by attracting a second, functional pollen tube. In typical flowering plants, two synergid cells beside the egg cell attract pollen tubes, one of which degenerates upon pollen tube discharge. We observed that fertilization was rescued when the second synergid cell accepted a wild-type pollen tube. Our results suggest that flowering plants precisely control the number of pollen tubes that arrive at each ovule and use a fertilization recovery mechanism to maximize the likelihood of successful seed set. Restricted pollination experiments showed that if sufficient pollen grains are provided, ovules attract a second pollen tube for recovery. These results support our previous finding that a long period of time is required for ovules to complete the system.
authors: JST ERATO Higashiyama Live-Holonics Project; Nagoya University; Furo-cho; Chikusa-ku; Nagoya; Aichi, Japan.
authors: Ryushiro D
authors: RD
authors: Kasahara
authors: Daisuke
authors: D
authors: Maruyama
authors: Tetsuya
authors: T
authors: Higashiyama
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D005306:Fertilization; D009154:Mutation; D056771:Ovule / Q000502:physiology*; D011058:Pollen; D053205:Pollen Tube / Q000254:growth & development*; D054817:Pollination; D012639:Seeds / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C548817:HAP2 protein, Arabidopsis
keywords: enhanced fertility phenotype; fertilization recovery system; persistent synergid cells; polysiphonogamy; restricted pollination; two pollen tubes