Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro | Wengier et al. BMC Plant Biology 2010 10 33 http 1471-2229 10 33 BMC Plant Biology RESEARCH ARTICLE Open Access STIL a peculiar molecule from styles specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro Diego L Wengier1 María A Mazzella1 Tamara M Salem1 Sheila McCormick3 4 Jorge P Muschietti1 2 Abstract Background LePRK1 and LePRK2 are two pollen receptor kinases localized to the plasma membrane where they are present in a high molecular weight complex LePRK complex . LePRK2 is phosphorylated in mature and germinated pollen but is dephosphorylated when pollen membranes are incubated with tomato or tobacco style extracts. Results Here we show that LePRK2 dephosphorylation is mediated by a heat- acid- base- DTT- and proteaseresistant component from tobacco styles. Using LePRK2 phosphorylation as a tracking assay for purification style exudates were subjected to chloroform extraction anionic exchange and C18 reverse-phase chromatography columns. We finally obtained a single 3 550 Da compound as determined by UV-MALDI-TOF MS that we named STIL for Style Interactor for LePRKs . STIL increased pollen tube lengths of in vitro germinated pollen in a dosedependent manner. Conclusion We propose that the LePRK complex perceives STIL resulting in LePRK2 dephosphorylation and an increase in pollen tube growth. Background In plants pollination and subsequent fertilization rely on an extensive and complex dialog between the tissues of the pistil both sporophytic and gametophytic and the pollen tube 1 2 . Numerous proteins and other molecules from both the female and male are thought to regulate the biochemical dialog established when the pollen grain lands on the stigma during pollen tube growth through the style and upon arrival at a synergid cell where the sperm cells are discharged. Some observations suggest that there is a hierarchy of signals in pollen tube germination and growth wherein a pollen tube
