PHOSPHORUS DEFICIENCY AND FLUORESCENT COMPOUNDS EXCRETED BY ROOTS AND SEEDS EXUDATES IN CROP PLANTS

YARYURA, P; CORDÓN, G; LEÓN, M; KERBER, N; PUCHEU, N; LAGORIO, MG; RUBIO, G; GARCÍA, A

Tucumán, Argentina

Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular, SAIB; 2009

SAIB

Confirming some previous results we show here that by inducing a stress condition (phosphorus shortage) some crops increase their excretion of fluorescent compounds in root exudates. In our experiments rapeseed plants entered into phosphorus shortage well before sunflower and soybean plants, which could be attributed to the seed size that limits the amount of phosphorus reserves in the seed. Chlorogenic acid is notoriously increased as well as scopoletin in rapeseed plant grown under phosphorus deficiency. Looking for a possible role for these secondary metabolites we tested the effect of root and seed exudates on the growth pattern induced on fungal growth. We observed the maximum induction of sclerotia formation with soybean seed exudates in Macrophominaphaseolina, although in our in vitro schemes the fungi finally overcame this condition and grew. It is as if both, an inducer of sclerotia and an inducer of myceliar growth were present in exudates, the effect of the latter somehow overriding the former. Distracting energy equivalents from a normal growing mycelium, inducing the formation of resistance structures like sclerotia, might be an opportunity to retard fungal invasion under a condition of extreme plant weakness.