Evaluation of the interaction between nitric oxide and the NAM-B1 factor on metal mobilization to wheat grains

CHECOVICH, MARIANA; SIMONTACCHI, M; SANTA-MARÍA, GE

Buenos Aires

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

In wheat, the GPC-B1 locus encodes the putative transcription factor NAM-B1, which is a member of the NAC family. The presence of this locus accelerates leaf senescence and increases the content of protein, iron (Fe) and zinc (Zn) in wheat grains. Nitric oxide (NO) has the capability to modulate leaf senescence as well as Fe homeostasis. Therefore, in this work we attempted to elucidate the possibility that NO interacts with NAM-B1 in the transport of Fe and Zn to the grain. Firstly, we evaluated if addition of the NO-donor, S-nitrosoglutathione (GSNO), as a foliar spray modifies the internal accumulation of NO through the use of the fluorescent dye DAF-FM DA. Results showed that NO levels increased following the application of that compound in leaves. Next, we performed greenhouse experiments. The SPAD index, non-destructive measurement of chlorophyll content, as well as the maximum quantum yield (Fv/Fm) differ between wheat lines that posses NAM-B1 and those in which mRNA levels were reduced by RNAi. Moreover, the pattern of Fe and Zn accumulation suggest a possible interaction among NO, NAM-B1 and the time of sowing.