Arabidopsis SGT1b is required for defense signaling conferred by several downy mildew resistance genes

TOR M., GORDON P., CUZICK A., EULGEM T., SINAPIDOU E., Mert-Turk F. , ...Daha Fazla

PLANT CELL, cilt.14, sa.5, ss.993-1003, 2002 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 14 Konu: 5
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1105/tpc.001123
  • Dergi Adı: PLANT CELL
  • Sayfa Sayıları: ss.993-1003


We describe the identification of a mutant in the Arabidopsis accession Columbia (Col-0) that exhibits enhanced downy mildew (edm1) susceptibility to several Peronospora parasitica isolates, including the RPP7-diagnostic isolate Hiks1. The mutation was mapped to chromosome IV and characterized physically as a 35-kb deletion spanning seven genes. One of these genes complemented the mutant to full wild-type resistance against all of the Peronospora isolates tested. This gene (AtSGT1b) encodes a predicted protein of 39.8 kD and is an Arabidopsis ortholog of yeast SGT1, which was described originally as a key regulatory protein in centromere function and ubiquitin-mediated proteolysis. AtSGT1b contains three tetratricopeptide repeats at the N terminus followed by a bipartite chord-containing SGT domain and an SGT-specific domain at the C terminus. We discuss the role of AtSGT1b in disease resistance and its possible involvement in ubiquitin-mediated proteolysis in plants.