News & Announcements

(July '10)

Our lab will present two oral presentations in the upcoming ASPB 2010 and ICSPR research conferences.

1. On 08/03/2010, at 2:30pm Dr. Ravi Palanivelu will present an oral presentation in the pollen biology major symposium of ASPB 2010, Montreal, Canada. The title of his talk, "Primed for success: pistil signals potentiate pollen tubes prior to fertilization".

This presentation will be part of Symposium V: Joint ASPB-CSPP: Pollen Biology (S05)
Organizers: Alice Cheung, University of Massachusetts, Anja Geitmann, University of Montreal, Heven Sze, University Of Maryland.

Access the schedule of this symposium here: http://www.aspb.org/meetings/pb-2010/schedule.cfm

Access the abstract here: http://abstracts.aspb.org/pb2010/public/S05/S052.html

2. On 08/05/2010, Dr. Tatsuya Tsukamoto will present an oral presentation in the "Fertilization" session of the XXI International Congress on Sexual Plant Reproduction for Sexual Plant Reproduction to be held in Bristol, Great Britain. The title of his talk, "Role of LORELEI in double fertilization and early seed development".

Access the schedule of this meeting and the talks in this meeting: http://www.sebiology.org/management/meetings/ICSPR/SexualPlantReproduction.html

Absract:

In plants, double fertilization requires successful sperm cell delivery in the female gametophyte followed by migration, recognition and fusion of the two sperm cells with two female gametes. We isolated a null allele (lre-5) of LORELEI (At4g26466), which encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein implicated in pollen tube reception by the female gametophyte. Although most lre-5 female gametophytes do not allow pollen tube reception, in those that do, early seed development is delayed. A fraction of lre-5/lre-5 seeds underwent abortion due to female gametophyte defect(s). The aborted seeds contained endosperm but no zygote/embryo, reminiscent of autonomous endosperm development in the pollen tube reception mutants scylla and sirene. However, unpollinated lre-5/lre-5 ovules did not initiate autonomous endosperm development and endosperm development in aborted seeds began after central cell fertilization. Thus, the egg cell likely remained unfertilized in aborted lre-5/lre-5 seeds. The lre-5/lre-5 ovules that remain undeveloped due to defective pollen tube reception did not induce synergid degeneration and repulsion of supernumerary pollen tubes. In ovules, LORELEI is expressed during pollen tube reception, double fertilization and early seed development. Arabidopsis genome contains three LORELEI-Like-GPI-anchored protein (LLG) genes (LLG1-At5g56170, LLG2-At2g20700 and LLG3-At4g28280). Null mutants of LLG1, the closest relative of LORELEI among three Arabidopsis LLG genes are fully fertile and did not enhance reproductive defects in lre-5/lre-5 pistils suggesting that LLG1 function is not redundant with that of LORELEI in the female gametophyte. Our results show that, besides pollen tube reception, LORELEI also functions during double fertilization and early seed development.

---------------------------------------------------------------------------------

Click here for other announcements.