Internode length in Pisum. The lrs mutation reduces gibberellin response and levels

We describe a new mutation, lrs, which reduces internode length in Pisum sativum L. The mutation appears to act by reducing both GA synthesis and the response to GA1. The levels of the 13-hydroxylated GAs, GA53, GA44, GA19, GA20, GA1, and GA8 in the lrs mutant were greatly reduced compared with the wild-type. The extent of the reduction in GA1 content in the apical tissues would, at least in part, account for the dwarf phenotype of the mutant. The reduced GA responsiveness of the new mutant was indicated by the inability of applied GA, to remove the difference in elongation between lrs and LRS plants. The lrs mutant appears to be unique amongst internode length genotypes, possessing characteristics of both GA synthesis and GA response mutants.