Molecular and biochemical bases of gametophytic self-incompatibility in solanaceae

T. H. Kao, A. G. McCubbin

Research output: Contribution to journalReview articlepeer-review

11 Scopus citations


Gametophytic self-incompatibility is a self/nonself recognition mechanism in flowering plants that allows the female reproductive organ to recognize and reject self pollen or pollen from genetically related individuals. For solanaceous species that display gametophytic self-incompatibility, a single multiallelic locus, called the S-locus, controls the outcome of pollination. S-allele-associated proteins (S-proteins) in the pistil have been identified based on their cosegregation with S-alleles. All the characteristics of S-proteins determined are consistent with their playing a role in self-incompatibility. Further, both gain-of-function and loss-of-function approaches have been used to show that S-proteins indeed control the ability of the pistil to recognize and reject self pollen. Since S-proteins have RNase activity and are glycoproteins, site-directed mutagenesis has been carried out to show that the RNase activity, but not the carbohydrate moiety, is essential for the function of S-proteins. Thus, the biochemical mechanism of S-protein-mediated rejection of self pollen involves the cytotoxic action of the RNase activity, and the S-allele specificity determinant of S-proteins lies in their amino acid sequence. Chimeric S-alleles between S1- and S3-alleles of Petunia inflata have been constructed and are being used to identify the S-allele specificity determinant of S-proteins. Models for how S-proteins specifically inhibit self pollen are discussed.

Original languageEnglish (US)
Pages (from-to)171-176
Number of pages6
JournalPlant Physiology and Biochemistry
Issue number3
StatePublished - 1997

All Science Journal Classification (ASJC) codes

  • Physiology
  • Genetics
  • Plant Science


Dive into the research topics of 'Molecular and biochemical bases of gametophytic self-incompatibility in solanaceae'. Together they form a unique fingerprint.

Cite this