Roots of nutrient-deprived Brachiaria species accumulate 1,3-di-O-trans-feruloylquinic acid

A novel di-hydroxycinnamoylquinic acid ester, 1,3-di-O-trans-feruloylquinic acid (DFQA), was isolated from roots of nutrient-deprived Brachiaria speci es - the most widely sown tropical forage grasses in South America. In cont rast to other so far characterized quinic-acid esters, DFQA exists in a cha ir conformation with the carboxylic group in the axial orientation. It accu mulates in older parts of the root system, but not in root apices or shoots . Higher levels were found in B. ruziziensis, which is poorly adapted to in fertile acid soils, than in well adapted B. decumbens. DFQA was also found in the soil, most likely as a result of root decay, because it was not dete cted in root exudates of plants cultivated in solution culture. Nitrogen an d phosphorus deficiency - but not aluminum toxicity or deprivation of other nutrients - stimulated its synthesis in roots. Its accumulation was correl ated with a shift in biomass partitioning toward the root system. (C) 2000 Elsevier Science Ltd. All rights reserved.