The S-locus specific glycoproteins of Brassica accumulate in the cell wall of developing stigma papillae☆

摘要

Self-incompatibilityinBrassicaoleraceaisnowviewedasacellularinteractionbetweenpollenandthepapillarcellsofthestigmasurface.Inthisspecies,theinhibitionofself-pollenoccursatthestigmasurfaceundertheinfluenceofS-locusspecificglycoproteins(SLSG).WeusedantibodiesspecificforaproteinepitopeofSLSGtostudythesubcellulardistributionofthesemoleculesinthestigmaticpapillae.TheantibodieshaveuncoveredaninterestingepitopepolymorphisminSLSGencodedbysubsetsofS-alleles,thusprovidinguswithusefulgeneticcontrolstodirectlyverifythespecificityoftheimmunolocalizationdata.ExaminationofthinsectionsofBrassicastigmasfollowingindirectimmunogoldlabelingshowedthatSLSGaccumulateinthepapillarcellwall,atthesitewhereinhibitionofself-pollentubedevelopmenthasbeenshowntooccur.Inaddition,theabsenceofgoldparticlesoverthepapillarcellwallsintheimmaturestigmasofveryyoungbuds,andtheintenselabelingofthesewallsinthestigmasofmaturebudsandopenflowers,correlateswellwiththeacquisitionoftheself-incompatibilityresponsebythedevelopingstigma.