Effect of seawater inorganic carbon enrichment on NO3- transporter and reduction enzyme gene expression in Zostera marina leaves

Abstract

In this work we have analysed the gene expression levels related to cytosolic nitrate homeostasis, including transporters and enzymes, in leaves of Zostera marina plants incubated in high HCO3- or in the absence of N. The expression levels of ZosmaNTR2, the only gene quoted as a high- affinity nitrate transporter belonging to NRT2 family in Z. marina genome, as well as its regulatory protein ZosmaNAR2, were induced in both conditions. Interestingly, expression levels of such genes were higher than the obtained for ZosmaCHL1 (ZosmaNPF6.3), which expression was lower in N-replete plants, but did not vary in response to HCO3-. These results suggest that the induction of the expression of the NO3- high-affinity transporter ZosmaNRT2 and its regulatory protein ZosmaNAR2 are the main response for the cytosolic NO3- decrease in both N-deficiency or in C-enrichment.