Protocatechuate is a universal growth substrate for members of the family Rhizobiaceae, and these bacteria utilize the aromatic compound via the beta-ketoadipate pathway. This report describes transcriptional controls exercised by different subgroups of the Rhizobiaceae over five enzymes that catalyze consecutive reactions in the pathway: protocatechuate oxygenase (EC 1.13.11.3), beta-carboxy-c...

Abstract A collection of 160 isolates of rhizobia nodulating Phaseolus vulgaris in three geographical regions in Tunisia was characterized by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified 16S rDNA, nifH and nodC genes. Nine groups of rhizobia were delineated: Rhizobium gallicum biovar (bv.) gallicum, Rhizobium leguminosarum bv. phaseoli and bv. v...

Intraspecific genetic variation can affect community structure and ecosystem processes (Bolnick et al. 2011). It can also influence phenotypic expression by genotypes within other species to produce genotype-by-genotype (G × G) interaction (Falconer & Mackay 1996). Evolution of one species drives correlated evolution of others when it causes G × G for fitness (Thompson 2005). However, the mecha...