title: Proteomics profiling reveals novel proteins and functions of the plant stigma exudate.
abstract: Proteomic analysis of the stigmatic exudate of Lilium longiflorum and Olea europaea led to the identification of 51 and 57 proteins, respectively, most of which are described for the first time in this secreted fluid. These results indicate that the stigmatic exudate is an extracellular environment metabolically active, participating in at least 80 different biological processes and 97 molecular functions. The stigma exudate showed a markedly catabolic profile and appeared to possess the enzyme machinery necessary to degrade large polysaccharides and lipids secreted by papillae to smaller units, allowing their incorporation into the pollen tube during pollination. It may also regulate pollen-tube growth in the pistil through the selective degradation of tube-wall components. Furthermore, some secreted proteins were involved in pollen-tube adhesion and orientation, as well as in programmed cell death of the papillae cells in response to either compatible pollination or incompatible pollen rejection. Finally, the results also revealed a putative cross-talk between genetic programmes regulating stress/defence and pollination responses in the stigma.
authors.affiliation: Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín (C.S.I.C.), C/ Profesor Albareda 1,18008 Granada, Spain.
authors.forename: Juan David
authors.initials: JD
authors.lastname: Rejón
authors.forename: François
authors.initials: F
authors.lastname: Delalande
authors.forename: Christine
authors.initials: C
authors.lastname: Schaeffer-Reiss
authors.forename: Christine
authors.initials: C
authors.lastname: Carapito
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zienkiewicz
authors.forename: Juan
authors.initials: J
authors.lastname: de Dios Alché
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Rodríguez-García
authors.forename: Alain
authors.initials: A
authors.lastname: Van Dorsselaer
authors.forename: Antonio Jesús
authors.initials: AJ
authors.lastname: Castro
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D035264:Flowers / Q000737:chemistry* / Q000378:metabolism; D027762:Lilium / Q000737:chemistry* / Q000378:metabolism; D031658:Olea / Q000737:chemistry* / Q000378:metabolism; D053147:Plant Exudates / Q000737:chemistry* / Q000378:metabolism*; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism*; D053205:Pollen Tube / Q000254:growth & development; D054817:Pollination; D011134:Polysaccharides / Q000378:metabolism; D040901:Proteomics / Q000379:methods
chemical_list: D053147:Plant Exudates; D010940:Plant Proteins; D011134:Polysaccharides
keywords: Eastern lily; exudate; olive; proteomics; secretome.; stigma