Pollen tube guidance by attractant molecules: LUREs.
Sexual reproduction in flowering plants requires pollen-tube guidance, which is thought to be mediated by chemoattractants derived from target ovules. To date, however, no convincing evidence has been reported of a particular molecule being the true attractant. Emerging data indicate that two synergid cells, which are on either side of the egg cell, emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen-tube guidance. Recently, it was demonstrated that LUREs (LURE1 and LURE2), cysteine-rich polypeptides secreted from the synergid cell, are the key molecules in pollen-tube guidance. In this review, we summarize the mechanism of pollen-tube guidance, with special focus on gametophytic guidance and the attractants.
Okuda
Satohiro
S
Nagoya University, Aichi, Japan. okuda@bio.nagoya-u.ac.jp
Higashiyama
Tetsuya
T
D056771:Ovule / Q000166:cytology / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D053205:Pollen Tube / Q000166:cytology / Q000254:growth & development*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D028083:Scrophulariaceae / Q000033:anatomy & histology; D015398:Signal Transduction
D010455:Peptides; D010940:Plant Proteins; D011994:Recombinant Proteins