Assimilate distribution in bean plants (Phaseolus vulgaris L.) during phosphate limitation

Abstract

The influence of phosphate deficiency on the increased 14C-assimilate transport from shoot to root of bean plants (Phaseolus vulgaris L.) was studied. The roots of plants were cultured in split configurations (a half of the root system was exposed to a short-term or long-term culture in phosphate-deficient nutrient medium, while the other half - in complete nutrient medium) to establish the conditions of translocation enhancement. It was found that both short term Pi stress applied to a part of root and longer localized phosphate deficiency is not sufficient to increase assimilate transport from the shoot to the root. Low concentration of Pi in tissues of the whole plant as a signal for changes in assimilate distribution and sugar accumulation in the roots is discussed.