Nitric oxide impairs Zinc uptake and mobilization in wheat plants

A. BUET; J.I. MORICONI; G.E. SANTA-MARIA; M. SIMONTACCHI

Buenos Aires

Congreso; VIII Meeting of the Society for Free Radical Biology and Medicine-South American Group; 2013

The effect of nitric oxide (NO), applied as S-nitrosoglutathione (GSNO), on Zn nutrition was evaluated in hydroponically cultured wheat plants (Triticum aestivum cv. Chinese Spring). At supraoptimal external Zn-concentrations, the concentration of Zn in plants was negatively affected by the presence of 100 µM GSNO. Zn concentration in roots declined from 92±16 to 54±8 nmol g-1 FW, after 17 days of treatment, while in shoots it declined from 117±9 to 79±7 nmol g-1 FW. When plants were exposed for 17 days to Zn deprivation, and then transferred to a complete nutritive solution for 48 h, net Zn uptake rate (NUR) was 4-fold higher than that measured for plants maintained in a complete nutrient solution. However, in Zn starved plants, the presence of NO for 48 h precluded these increase in NUR. Additionally, root-to-shoot Zn-translocation rate in plants suffering from Zn deficiency (3,1 nmol Zn g-1 FW h-1) markedly decreased by the presence of 100 µM GSNO in the nutrient solution (1,5 nmol Zn g-1 FW h-1). Our results suggest a role for NO in the modulation of Zn uptake and in root-to-shoot movement when plants are cultured under different Zn availability.