Plant Molecular Biology

, Volume 27, Issue 3, pp 499–511

cDNA cloning and molecular analysis of two self-incompatibility alleles from apple

  • Wim Broothaerts
  • Greet A. Janssens
  • Paul Proost
  • Willem F. Broekaert
Research Article

DOI: 10.1007/BF00019317

Cite this article as:
Broothaerts, W., Janssens, G.A., Proost, P. et al. Plant Mol Biol (1995) 27: 499. doi:10.1007/BF00019317

Abstract

Complementary DNA clones representing two alleles of the self-incompatibility (S) locus of apple (Malus × domestica Borkh.) have been isolated and characterised. One of the alleles corresponds to a 29 kDa ribonuclease (S-RNase) that was purified from pistil tissue. On northern blots, both cDNAs hybridized to a transcript that was only present in pistils and not in the other plant tissues analysed. Corresponding genomic sequences, amplified by PCR, were found to contain a single intron of 138 bp and 1100 bp respectively. Comparison of both sequences shows that the cDNAs encode mature proteins containing 65% of identical residues. Eight invariable cysteine residues, conserved regions around two histidines thought to play a role in RNA catalysis, and a number of other distinct residues are conserved between the apple S-RNases and similar proteins in the family Solanaceae. As this is the first report of sequences of S-alleles from a species belonging to a family that is not related with the Solanaceae, the structural features of S-RNase deduced from a comparison of their sequences are discussed.

Key words

Malus × domesticapistilpollinationribonucleaseS alleleself-incompatibility

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Wim Broothaerts
    • 1
    • 2
  • Greet A. Janssens
    • 1
  • Paul Proost
    • 3
  • Willem F. Broekaert
    • 1
  1. 1.F.A. Janssens Laboratory of GeneticsKatholieke Universiteit LeuvenleuvenBelgium
  2. 2.Centre for Fruit CultureKatholieke Universiteit LeuvenleuvenBelgium
  3. 3.Rega Institute for Medical ResearchKatholieke Universiteit LeuvenLeuvenBelgium