Ureid metabolism and transport in Arabidopsis plants under different nutritional conditions

LESCANO, CARLOS IGNACIO; MARTINI, CAROLINA; IZQUIERDO, JULIANA; TESSI, TOMÁS MARÍA; GONZALEZ, CLAUDIO ALEJANDRO; DESIMONE MARCELO

Mar del Plata

Congreso; XXIX Reunión Argentina de Fisiología Vegetal; 2012

Sociedad Argentina de Fisiologia Vegetal

The ureides play a central role in nitrogen transport in nodulating tropical legumes. Functional genomic estudies revelled that the complete enzyme set for ureides synthesis and a family of ureides permeases are widwly distributed in the plant kingdom suggesting their participation in distinc physiological porcesses. Here, the effect of nutritional conditions on ureides accumulation was estudied in Arabidopsis plants. Elevated concentrationof allantoin were observed in alla-1 mutants grown with low C/N levels, but a noticeable morphological phenotype remained elusive. AtUPS5 transports allantoin and its expressed in the root cortex and endodermis. Root development of ups5 plants was delayed in comparison with wt plants,when grown on high concentration of ammonium nitrate. This phenotype could be reverted by addition of sucrose. A possible rol of allantoin synthesis and transport to detoxify excess of reduced nitrogen is discussed