Two novel chromosomal loci influence cultivar-specific nodulation failure in the interaction between strain ANU794 and subterranean clover cultivar Woogenellup.

Abstract

The nodulation failure resulting from the interaction between Rhizobium leguminosarum biovar trifolii strain ANU794 and the Trifolium subterraneum cv. Woogenellup was examined by transposon mutagenesis to resolve whether multiple determinants were involved in cultivar-specificity. Three new transposon-induced mutants of ANU794 (W72, W78 and W710) with significantly enhanced nodulation ability on cv. Woogenellup were identified. The W72 and W78 mutations are chromosomally-located, whereas the W710 mutation is plasmid-located. The ethylene synthesis inhibitor, aminoethoxyvinylglycine, fails to enhance the nodulation ability of ANU794, ANU7943 (csn1