Ineffective root nodule symbiosis
Legume crops are central to sustainable agricultural practices and food security, as they have a reduced mineral nitrogen fertiliser dependency, but exhibit high protein content. This is rooted in their mutualistic interaction with nitrogen-fixing rhizobia bacteria. In agricultural fields, ineffective rhizobia (little or no nitrogen fixation) can turn into parasites and outcompete beneficial strains. Although this is a limitation for biological fertilisation, the genetic basis underlying this parasitic behaviour is poorly investigated.