Involvement of extracellular calcium influx in the self-incompatibility response of Papaver rhoeas

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Colleges, School and Institutes


We have previously demonstrated that increases in cytosolic free Ca2+ are triggered by the self-incompatibility (SI) response in incompatible Papaver rhoeas (the field poppy) pollen. However, one key question that has not been answered is whether extracellular Ca2+ may be involved. To address this question, we have used an ion-selective vibrating probe to measure changes in extracellular Ca2+ fluxes around poppy pollen tubes. Our data reveal several findings. First, we confirm that there is an oscillating Ca2+ influx directed at the apex of the pollen tube; we also provide evidence that Ca2+ influx also occurs at the shanks of pollen tubes. Second, upon challenge with self-incompatibility (S) proteins, there is a stimulation of Ca2+ influx along the shank of incompatible pollen tubes, approximately 50 mum behind the pollen tube tip. This demonstration of SI-induced Ca2+ influx suggests a role for influx of extracellular Ca2+ in the SI response.


Original languageEnglish
Pages (from-to)333-345
Number of pages13
JournalThe Plant journal : for cell and molecular biology
Issue number3
Publication statusPublished - 1 Feb 2002


  • self-incompatibility, Papaver rhoeas, Ca2+ signalling and calcium selective vibrating probe