Analysis of infection thread development using Gfp- and DsRed-expressing Sinorhizobium meliloti.

Sinorhizobium meliloti growth inside infection threads was monitored after inoculation of alfalfa with red- or green-tagged bacteria. Most threads were populated with single bacterial types. Mixed infections were present but gave mixed nodules less often than expected. These patterns are explained by a model describing bacterial growth during infection.