Nitric oxide impairs Zinc uptake and mobilization in wheat plants

BUET, AGUSTINA; MORICONI, JORGE I.; SANTA-MARIA, GUILLERMO E.; SIMONTACCHI, MARCELA

Chascomús

Congreso; XV Jornadas Anuales de la Sociedad Argentina de Biología; 2013

Sociedad Argentina de Biología

In this study, the effect of nitric oxide (NO) on net Zn-uptake and root-to-shoot translocation rates was evaluated in wheat plants (Triticum aestivum) cv. Chinese Spring. The plants were hydroponically cultured under supra-optimal and deficient Zn availabilities. S-nitrosogluthathione (GSNO), as NO donor, was applied in the nutrient solution at a final concentration of 100 µM. After 17 days of culture, the Zn-well-supplied plants exposed to NO showed lower concentration of Zn in tissues than those not exposed. The Zn concentration in roots decreased from 92±16 to 54±8 nmol g-1 FW, while in shoots it declined from 117±9 to 79±7 nmol g-1 FW. In Zn-deprived plants, this effect of NO was not observed. In addition, Zn-deprived plants were transferred to a complete nutrient solution for 48 h and Zn net uptake (NUR) and root-to-shoot translocation rates were estimated. The NUR was 4-fold higher than that measured for plants maintained in a complete nutrient solution. The exposition to NO for 48 h repressed this increase. Root-to-shoot Zn-translocation rate was also affected by NO. It declined from 3.1 to 1.5 nmol Zn g-1 FW h-1. Our results suggest a reversible action of NO in the modulation of uptake and root-to-shoot translocation in plants cultured under different Zn availability.