The effect of glucosinolates (mustard oil glycosides) and products of their enzymic degradation on the infectivity of turnip mosaic virus

The effect of glucosinolates sinigrin, progoitrin, epiprogroitrin, gluconapin, gluconapoleiferin, glucobrassicanapin, glucotropaeolin and gluconasturtiin without and with the glucosinolate-degrading enzyme (myrosinase, EC:3.2.3.1.), on the infectivity of turnip mosaic virus was studied. Little or no effect was observed when the intact glucosinolate (2.5 μmol cm⁻³) was added to the suspension of turnip mosaic virus (TuMV, isolate Ruzyně; 0.2 mg cm⁻³ in 0.01 M potassium phosphate buffer) at both pH 7 and pH 6. A significant decrease of virus infectivity was, however, observed when 0.25, 1.25 and 2.5 μmol cm⁻³ of the glucosinolate together with 0.31, 1.56 and 3.13 mg cm⁻³ of the myrosinase, respectively, was added to the virus suspension of both pH 7 and pH 6. The effect, which was greater at pH 6, was most intense with sinalbin and glucobrassicin substrates.