title: Characterization of a newly identified rice chitinase-like protein (OsCLP) homologous to xylanase inhibitor.
abstract: BACKGROUND
  During rice blast fungal attack, plant xylanase inhibitor proteins (XIPs) that inhibit fungal xylanase activity are believed to act as a defensive barrier against fungal pathogens. To understand the role of XIPs in rice, a xylanase inhibitor was cloned from rice. The expression of this gene was examined at the transcriptional/translational levels during compatible and incompatible interactions, and the biochemical activity of this protein was also examined.
  
  
  RESULTS
  Sequence alignment revealed that the deduced amino acid sequence of OsCLP shares a high degree of similarity with that of other plant TAXI-type XIPs. However, recombinant OsCLP did not display inhibitory activity against endo-1,4-β-xylanase enzymes from Aureobasidium pullulans (A. pullulans) or Trichoderma viride (T. viride). Instead, an in-gel activity assay revealed strong chitinase activity. The transcription and translation of OsCLP were highly induced when rice was exposed to pathogens in an incompatible interaction. In addition, exogenous treatment with OsCLP affected the growth of the basidiomycete fungus Rhizoctonia solani through degradation of the hyphal cell wall. These data suggest that OsCLP, which has chitinase activity, may play an important role in plant defenses against pathogens.
  
  
  CONCLUSIONS
  Taken together, our results demonstrate that OsCLP may have antifungal activity. This protein may directly inhibit pathogen growth by degrading fungal cell wall components through chitinase activity.
authors: Division of Applied Life Science (BK21 program), Gyeongsang National University, Jinju, 660-701, South Korea.
authors: Jingni
authors: J
authors: Wu
authors: Yiming
authors: Y
authors: Wang
authors: Sun Tae
authors: ST
authors: Kim
authors: Sang Gon
authors: SG
authors: Kim
authors: Kyu Young
authors: KY
authors: Kang
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology; D043364:Endo-1,4-beta Xylanases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005656:Fungal Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D012232:Rhizoctonia / Q000187:drug effects; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014242:Trichoderma / Q000201:enzymology
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D043364:Endo-1,4-beta Xylanases