Molecular recognition and response in pollen and pistil interactions.
Many bisexual flowering plants possess a reproductive strategy called self-incompatibility (SI) that enables the female tissue (the pistil) to reject self but accept non-self pollen for fertilization. Three different SI mechanisms are discussed, each controlled by two separate, highly polymorphic genes at the S-locus. For the Solanaceae and Papaveraceae types, the genes controlling female function in SI, the S-RNase gene and the S-gene, respectively, have been identified. For the Brassicaceae type, the gene controlling male function, SCR/SP11, and the gene controlling female function, SRK, have been identified. The S-RNase based mechanism involves degradation of RNA of self-pollen tubes; the S-protein based mechanism involves a signal transduction cascade in pollen, including a transient rise in [Ca(2+)]i and subsequent protein phosphorylation/dephosphorylation; and the SRK (a receptor kinase) based mechanism involves interaction of a pollen ligand, SCR/SP11, with SRK, followed by a signal transduction cascade in the stigmatic surface cell.
McCubbin
A G
AG
Department of Biochemistry and Molecular Biology, 403 Althouse Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802-4500, USA. agm3@psu.edu
Kao
T
T
D019607:Brassicaceae / Q000502:physiology*; D010207:Papaver / Q000502:physiology*; D010946:Plants, Medicinal; D011058:Pollen / Q000502:physiology*; D019657:Solanaceae / Q000502:physiology*