Stress responses in alfalfa (Medicago sativa L.). 15. Characterization and expression patterns of members of a subset of the chalcone synthase multigene family.

We have identified five different full length chalcone synthase (CHS) cDNA clones from a cDNA library produced from transcripts isolated from an elicitor-treated alfalfa cell suspension culture. Nucleotide sequence similarity between the clones varied from 88-93%. Oligonucleotides based on divergent sequences in the 5'-untranslated regions of the clones could distinguish individual genes, or groups of genes, and their corresponding transcripts.

Stress Responses in Alfalfa (Medicago sativa L.): I. Induction of Phenylpropanoid Biosynthesis and Hydrolytic Enzymes in Elicitor-Treated Cell Suspension Cultures.

Alfalfa (Medicago sativa L.) cell suspension cultures accumulated high concentrations of the pterocarpan phytoalexin medicarpin, reaching a maximum within 24 hours after exposure to an elicitor preparation from cell walls of the phytopathogenic fungus Colletotrichum lindemuthianum. This was preceded by increases in the extractable activities of the isoflavonoid biosynthetic enzymes l-phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, 4-coumarate coenzyme A-ligase, chalcone synthase, chalcone isomerase, and isoflavone O-methyltransferase.

Local and systemic changes in gene expression induced in tomato plants by wounding and by elicitor treatment.

Tomato (Lycopersicon esculentum Mill. cv. Moneymaker) plants have been wounded to induce the accumulation of proteinase-inhibitor proteins (PI proteins) at the local site of injury and systemically in unwounded tissues.

Analysis of inter-relationship of jackbean seed components by two-dimensional mapping of iodinated tryptic peptides.

The subunits of Concanavalin A, α-mannosidase and the main storage protein of jackbeans have been compared using the technique of peptide-mapping of iodinated tryptic peptides. The results indicate there is no structural relatedness between the lectin, enzyme and storage protein. Peptide maps of the lectin fragments which copurify with the intact subunit indicate that cleavage points additional to that between residues 118-119 most probably occur.

Endopeptidase activity in jackbeans and its effect on Concanavalin A.

Endopeptidase activity in mature jackbeans has been characterised. One major activity is present, that of a neutral metallo-endopeptidase. Using specific inhibitors it can be shown that the Concanavalin A-associated fragments are not formed by proteolytic degradation of the intact subunit on hydration of the tissue.