The Involvement of Endogenous Phenolic Compounds in the Response of Pea Seedling Roots to Inoculation with Rhizobium leguminosarum at Various Temperatures

Endogenous phenolic compounds (PC) affecting Rhizobium leguminosarum bv. viceae propagation were isolated from the roots of etiolated pea (Pisum sativum L.) seedlings before and within one or two day after inoculation. It was established that, during the first day after inoculation, PC-induced stimulation of bacterial growth in roots was replaced by its inhibition, which was somewhat more pronounced at 8°C. The ratio between PC fractions was also changed during the first day after inoculation, especially strongly at low temperature; and this was evidently the cause for Rhizobium growth inhibition in root cells.