A multicomponent, elicitor-inducible cystatin complex in tomato, Solanum lycopersicum.
We assessed the ability of the fungal elicitor arachidonic acid to induce cystatin genes in tomato (Solanum lycopersicum), using a cDNA expression library from arachidonate-treated leaves. The cDNAs of two novel cystatins were isolated, coding for an approx. 11-kDa protein, SlCYS10; and for a 23.6-kDa protein, SlCYS9, bearing an N-terminal signal peptide and a long, 11.5-kDa extension at the C terminus. Both genes were induced by arachidonate but not by methyl jasmonate, an inducer of the 88-kDa eight-unit cystatin, multicystatin, accumulated in the cytosol of leaf cells upon herbivory. A truncated form of SlCYS9, tSlCYS9, was produced by deletion of the C-terminal extension to assess the influence of this structural element on the cystatin moiety. As shown by kinetic and stability assays with recombinant variants expressed in Escherichia coli, deleting the extension influenced both the overall stability and inhibitory potency of SlCYS9 against cysteine proteases of herbivorous organisms. These findings provide evidence for a multicomponent elicitor-inducible cystatin complex in tomato, including at least 10 cystatin units produced via two metabolic routes.
Girard
Cécile
C
Département de phytologie, CRH/INAF, Université Laval, Québec, Canada G1K 7P4.
Rivard
Daniel
D
Département de phytologie, CRH/INAF, Université Laval, Québec, Canada G1K 7P4.
Kiggundu
Andrew
A
Forestry and Agricultural Biotechnology Institute, Botany Department, University of Pretoria, Pretoria 0002, South Africa.
Kunert
Karl
K
Forestry and Agricultural Biotechnology Institute, Botany Department, University of Pretoria, Pretoria 0002, South Africa.
Gleddie
Stephen C
SC
Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada K1A 0C6.
Cloutier
Conrad
C
Département de biologie, Centre de recherche en horticulture, Université Laval, Québec QC, Canada G1K 7P4.
Michaud
Dominique
D
Département de phytologie, CRH/INAF, Université Laval, Québec, Canada G1K 7P4.
D000085:Acetates / Q000494:pharmacology*; D000595:Amino Acid Sequence; D001095:Arachidonic Acids / Q000494:pharmacology*; D001483:Base Sequence; D003517:Cyclopentanes / Q000494:pharmacology*; D015891:Cystatins / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics / Q000494:pharmacology; D018076:DNA, Complementary; D018744:DNA, Plant; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D018745:Genome, Plant; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment
D000085:Acetates; D001095:Arachidonic Acids; D003517:Cyclopentanes; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D018076:DNA, Complementary; D018744:DNA, Plant; D046912:Multiprotein Complexes; D054883:Oxylipins; D011994:Recombinant Proteins; C072239:methyl jasmonate