Enhancement of infection thread formation by Rhizobium etli incubated with bean seed lectin

Rhizobium etli infects its host Phaseolus vulgaris by means of a structure called infection thread. Although there are several reports related to infection thread promoting factors, none of them deals with this symbiotic pair. In this study we report that incubating R. etli with P. vulgaris seed lectin, prior to plant inoculation, significantly increased the infection thread counting in plants grown in plastic pouches. However, promotion of infection thread formation was not significantly correlated, at least under our experimental conditions, with an increase in nodule number.