Nitric oxide impairs Zinc uptake and mobilization in wheat plants

BUET, A; MORICONI, JI; GUILLERMO E. SANTA MARÍA; SIMONTACCHI, M

Buenos Aires

Congreso; VIII International Congress Society for Free Radical Biology and Medicine South American Group; 2013

The effect of nitric oxide (NO) applied as S-nitrosoglutathione (GSNO) on Zn nutritional status was evaluated in wheat plants (Triticum aestivum cv. Chinese Spring) cultured in nutrient solution. The concentration of Zn in tissues was negatively affected by the presence of 100 µM GSNO. Zn concentration in roots declined due to the presence of NO donor from 95±x to 55±x nmol g-1 FW, after 17 days of treatment. A similar behaviour was observed in shoots. 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) resulted 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 the increase in NUR. Additionally, root-to-shoot Zn translocation rate exhibited by plants suffering from Zn deficiency (3 nmol Zn g-1 FW h-1) decreased in 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 root-to-shoot remobilization when plants are cultured under different Zn availability.