Systemic induction of a Phytolacca insularis antiviral protein gene by mechanical wounding, jasmonic acid, and abscisic acid.
We have isolated a gene encoding a ribosome-inactivating protein (RIP) from Phytolacca insularis, designated as P. insularis antiviral protein 2 (PIP2). The PIP2 gene contained an open reading frame encoding a polypeptide of 315 amino acids. The deduced amino acid sequence of PIP2 was similar to those of other RIPs from Phytolacca plants. Recombinant PIP2 was expressed in Escherichia coli and was used to investigate its biological activities. Recombinant PIP2 inhibited protein synthesis in rabbit reticulocyte lysate by inactivating ribosomes through N-glycosidase activity. It also exhibited antiviral activity against tobacco mosaic virus (TMV). Expression of the PIP2 gene was developmentally regulated in leaves and roots of P. insularis. Furthermore, expression of the PIP2 gene was induced in leaves by mechanical wounding. The wound induction of the PIP2 gene was systemic. Expression of the PIP2 gene also increased in leaves in a systemic manner after treatment with jasmonic acid (JA) and abscisic acid (ABA), but not with salicylic acid (SA). These results imply that plants have employed the systemic synthesis of the defensive proteins to protect themselves more efficiently from infecting viruses.
Song
S K
SK
Department of Molecular Biology and Research Center for Cell Differentiation, Seoul National University, Korea.
Choi
Y
Y
Moon
Y H
YH
Kim
S G
SG
Choi
Y D
YD
Lee
J S
JS
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D015139:Blotting, Southern; D003517:Cyclopentanes / Q000494:pharmacology*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000235:genetics; D004274:DNA, Recombinant / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases; D054883:Oxylipins; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D010947:Plants, Toxic; D014176:Protein Biosynthesis; D018749:RNA, Plant / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D054789:Ribosome Inactivating Proteins, Type 1; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013314:Stress, Mechanical; D014026:Nicotiana / Q000235:genetics / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000254:growth & development
D003517:Cyclopentanes; D018076:DNA, Complementary; D018744:DNA, Plant; D004274:DNA, Recombinant; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D018749:RNA, Plant; D054789:Ribosome Inactivating Proteins, Type 1; C011006:jasmonic acid; D000040:Abscisic Acid; D009699:N-Glycosyl Hydrolases; C024275:pokeweed antiviral protein