Molecular characterization of pepper germin-like protein as the novel PR-16 family of pathogenesis-related proteins isolated during the resistance response to viral and bacterial infection.
To understand the molecular defense mechanism controlling the hypersensitive response (HR) better, we examined the hot pepper plant (Capsicum annuum L. cv. Bugang), which exhibits an HR in response to infection by Tobacco mosaic virus pathotype P0 (TMV-P0). A full-length cDNA clone was isolated by differential screening of a cDNA library that was constructed with mRNA extracted from hot pepper leaves during the resistance response to TMV-P0. The predicted amino acid sequence of the cDNA clone exhibited a high sequence similarity to germin-like protein (GLP). The CaGLP1 (Capsicum annuum GLP1) cDNA contains a single open reading frame of 660 bp encoding 220 amino acid residues. Upon inoculation with TMV or Xanthomonas, CaGLP1 transcripts were specifically accumulated in the incompatible interaction but not in the compatible interaction. In plants treated with salicylic acid (SA) or ethephon, which are signal molecules in the defense-related signal transduction pathway, CaGLP1 transcripts were accumulated rapidly. As far as we know, this is the first report that plant GLPs can be specifically induced during a defense response against viral infection. These data suggest that in the hot pepper plant CaGLP1 may be involved in the defense response to viral pathogens, and thus be classified as a new family of PR proteins, 'PR-16'.
Park
Chang-Jin
CJ
School of Life Sciences and Biotechnology, Korea University, 1, 5-ga, Anam-dong, Sungbuk-gu, 136-701, Seoul, Republic of Korea.
An
Jong-Min
JM
Shin
Yun-Chul
YC
Kim
Ki-Jeong
KJ
Lee
Boo-Ja
BJ
Paek
Kyung-Hee
KH
D000595:Amino Acid Sequence; D001483:Base Sequence; D002212:Capsicum / Q000235:genetics* / Q000382:microbiology* / Q000821:virology; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D006023:Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology* / Q000821:virology*; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology / Q000821:virology; D010940:Plant Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity / Q000502:physiology
D017931:DNA Primers; D006023:Glycoproteins; D010940:Plant Proteins