FUNGICIDAL ACTIVITY OF THE SYNTHETIC PUTRESCINE ANALOG, (E)-1,4-DIAMINOBUT-2-ENE, AND DERIVATIVES

The putrescine analogue, (E)-1,4-diaminobut-2-ene (E-BED), synthesized as the dihydrochloride salt, controlled five economically important c rop pathogens, Erysiphe graminis DC fsp. hordei Marchal, Uromyces vici ae-fabae (Pers.) Schroet, Botrytisfabae Sardina, Podosphaera leucotric ha (Ell. & Ev.) Salm. and Phytophthora infestans (Mont) De Bary. The Z -isomer, Z-BED, was also fungicidal, although less so than E-BED. Post -inoculation treatment with E-BED gave greater control of powdery mild ew infection on barley and rust and chocolate spot on broad bean than did pre-inoculation application. It was also effective in vitro agains t Botrytis cinerea Pers. ex Fr., Pyricularia oxyzae Br. & Cav. and Pyr enophora avenae Ito & Karibay. When P. avenae was grown in the presenc e of E-BED dihydrochloride at 81.5 mg litre-1, growth was reduced by 5 8% and there were significant reductions in soluble ornithine decarbox ylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) activity . These changes were accompanied by a sevenfold increase in putrescine concentration, a 60% increase in spermine concentration and a 32% red uction in spermidine concentration within the fungal tissue.