Physiological, Chemical and Metabolite Profiling of Pectobacterium carotovorum-Inoculated Tomato Plants Grown in Nutrient-Amended Soils

This study evaluated the effects of a plant pathogenic bacterium <i>Pectobacterium carotovorum</i> strain BD163 inoculation and nutrient solution (CaCO₃ (2 mM), NaCl (1 mM) and K₂Cr₂O₇ (0.001 mM)) on the growth, photosynthesis, nutrient uptake and metabolomics of tomato seedlings. The experiment had four experimental treatments (1. solution + BD163 inoculation, 2. solution alone, 3. BD163 inoculation, 4. control). Plant growth and photosynthesis responses were minimal, and differences in nutrient assimilation and metabolite profiles were clear-cut. Of the photosynthesis parameters, only water use efficiency was impacted; it was higher in the bacterium-only treatment and unchanged in the other treatments. The quantities of boron, bismuth and nickel were affected, accumulating mostly in the "solution + BD163 inoculation" experimental set. Principal component analysis of metabolomics data separated the treatments into three groupings; group 1 was the double treatment, group 2 was the nutrient solution treatment and, finally, group 3 was the <i>P. carotovorum</i> and control treatments. Correlation analysis of the data showed an assumed interdependence of several plant factors. The authors concluded that the interaction between the bacterium, the plant and the nutrient solution is complex and more pronounced at the chemical and metabolite level than at the growth and photosynthesis level.