Biochemical and molecular biological studies on infection (Ascochyta rabiei)-induced thaumatin-like proteins from chickpea plants (Cicer arietinum L.).
A pathogenesis-related protein induced by infection with Ascochyta rabiei was purified from intercellular washing fluid of chickpea (Cicer arietinum L.) leaves. Amino-terminal sequencing identified the protein, named PR-5a, as a thaumatin-like protein. The isoelectric point was determined with 6.5 and the molecular mass is 16 kDa. Therefore, chickpea PR-5a is the first dicot member of a TLP subgroup containing small TLPs with a molecular weight between 15 and 18 kDa. PR-5a shows no antifungal activity towards A. rabiei. Screening of a chickpea cDNA library led to the isolation of a cDNA clone (p5a-241) for this protein. A second cDNA clone (ELR112) encoding a TLP was isolated using differential hybridisation of cDNA libraries obtained from elicited and water treated cell suspension cultures of chickpea. The deduced protein (PR-5b) has a molecular mass of 22 kDa. PR-5b is postulated to be located in the vacuole due to the presence of a respective N-terminal signal peptide and a carboxy-terminal extension. Southern blot analyses showed that ELR112 and p5a-241 represent single copy genes. During fungal infection of chickpea plants expression of both genes proceeds much faster in an A. rabiei resistant cultivar than in a susceptible one.
Hanselle
T
T
Institute for Plant Biochemistry and Biotechnology, University of Münster, Germany.
Ichinoseb
Y
Y
Barz
W
W
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000737:chemistry / Q000472:pathogenicity*; D029863:Cicer / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D017931:DNA Primers; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D015723:Gene Library; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010935:Plant Diseases; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013549:Sweetening Agents
D017931:DNA Primers; D018744:DNA, Plant; D010940:Plant Proteins; D013549:Sweetening Agents; C003427:thaumatin protein, plant