Inhibition of barley and Arabidopsis callus growth by lysine analogues

Abstract

The inhibitory effect of the lysine analogues S-2-aminoethyl-L-cysteine, DL-δ-hydroxylysine and DL-α-aminocaprylic acid on the growth of Arabidopsis thaliana and barley callus was studied. The relief of analogue inhibition was tested by adding lysine in the culture medium in the presence or absence of arginine since lysine itself markedly affected callus growth and that arginine reversed that inhibition. In both species, inhibition due to DL-α-amino caprylic acid was not relieved by further addition of lysine, arginine or lysine plus arginine. In barley as in Arabidopsis, callus growth was strongly inhibited by S-2-aminoethyl-l-cysteine. Lysine antagonised the growth inhibitory effect only in presence of arginine which supplied singly did not influence S-2-aminoethyl-L-cysteine toxicity. On the other hand, the single addition of arginine to the culture medium containing DL-δ-hydroxylysine led to normal growth of Arabidopsis callus and near normal growth of barley callus. Isolation of lysine overproducing mutants is proposed by selecting cell lines which grow on a medium containing S-2-aminoethyl-L-cysteine and arginine.