AUTHORS: Sonja Weber, Missouri Western State University; Nora Burroughs, Missouri Western State University; Rene Frye, Missouri Western State University; Angel Justus, and Csengele Barta, Missouri Western State University
ABSTRACT: Invasive species often employ competitive strategies as the release of allelopathic metabolites into the environment, which negatively impact native species. Velvet bean (Mucuna pruriens, VB) has been reported to produce a variety of such toxic compounds, such as L-dopa, tryptamines, phenols, and tannins, with notable allelopathic activities, suppressing the growth and development of competing native species, but without any autotoxic effects. Our current study focused on the chemical impact of degrading VB seeds on tomato seedlings. We found that VB seed inclusions significantly altered tomato growth, biomass, chlorophyll concentrations, light harvesting and processing ability, and photosynthetic efficiency. VB seed coat inclusions inhibited growth and leaf development, and leaves contained 30% less chlorophyll than controls. VB seed coat soil inclusions also induced an over 50% reduction of maximum and effective quantum yields and defects in photosynthetic energy processing, with a corresponding shift in energy processing away from photochemistry towards non-photochemical quenching. VB endosperm, however, stimulated tomato growth and leaf expansion, resulting in doubled biomass compared to controls. Plants growing in soil enriched with VB endosperm inclusions exhibited higher total chlorophyll concentrations and more efficient light harvesting and photochemical energy processing capacity compared to controls, indicators for enhanced photosynthetic capacity in these plants.
