NO2-drived NO3– metabolism in leaves

Abstract

Atmospheric nitrogen dioxide (NO 2) can be dry/wet deposited into plant leaves mainly through stomata, with a small fraction of cuticle deposition. Plants in nature present a wide variation in NO 2 assimilation and the resistance. The ability of leaf NO 2 uptake and efficient remobilization of NO 2-derived NO 3-/NO 2 is important for normal plant growth and to withstand nitrogen deprivation. Moreover, leaf-and root-derived NO 3 metabolisms have both links and differences. This review emphasizes on the fates of NO 2-drived NO 3-, including i) the assimilation into amino acids, ii) accumulation in vacuoles, and iii) reemission by NO x (NO and/or NO 2), and discuss metabolic differences of NO 2-drived and root-derived NO 3 . Special attention is drawn to NO x evolution in apoplast and symplast of leaves and its control to stomatal dynamics. Moreover, further progress is proposed to get a better understanding of the dynamic uptake of NO 2 and NO 3 transporters in leaves.

Analyzing temporal changes in urban forest structure and the effect on air quality improvement

“…It is assumed that the absorbed SO 2 , uptaken predominantly through leaf stoma, dissolves in the aqueous phase of inner-leaf cell walls (apoplast) or in the cytoplasm, producing bisulfite and sulfite ions and eventually forming sulfurous or sulfuric acid (Nowak, 1994;Omasa et al, 2002). NO 2 may be assimilated into amino acids or accumulated in vacuoles once absorbed through stomata (Chaparro-suarez, Meixner, & Kesselmeier, 2011;Gasche et al, 2002;Hu, 2011;Nowak, 1994). Once O 3 is uptaken through stomata, it may be ozonolyzed in the sub-stomatal cavity and apoplast (Temmerman et al, 2002).…”

Nitrate transporters in leaves and their potential roles in foliar uptake of nitrogen dioxideâ€

“…Previous studies on foliar uptake of NO 2 mainly focused on the deposition pathways, metabolic processes associated with NO 2 -derived NO − 3 (Hu, 2011; Hu et al, 2014), and downstream products of NO 2 -N assimilation (Nussbaum et al, 1993; Weber et al, 1995). The current state of knowledge on the potential plant responses to NO 2 exposure is summarized in Table 1.…”