Rhizospheric NO interacts with the acquisition of reduced N sources by the roots of European beech (Fagus sylvatica L.)

Abstract

a b s t r a c tThe gas phase of the soil plays an important role in plant growth and development. We investigated the effect of rhizospheric NO as a signalling compound for N uptake of beech roots. Following exposure to NO, ammonium and glutamine uptake into roots were determined using 15 N-labelling, and gene expression of selected transporters was analysed by quantitative real-time PCR. Uptake of both N sources increased significantly with elevated NO concentration. However, with one exception, this increase was not reflected in up-regulation of expression of the respective transporters.

Nitrogen Nutrition of Trees in Temperate Forests—The Significance of Nitrogen Availability in the Pedosphere and Atmosphere

“…In this context, microbial NO produced in significant amounts during nitrification and denitrification seems to be of particular significance [86]. Rhizospheric NO was shown to modulate the uptake of N compounds by tree roots [85,87,88]. Apparently, NO of microbial origin in the soil is sensed by the roots and functions as a signal that determines the competitive strength of N acquisition by the roots relative to microbial use.…”

IDF World Diabetes Congress 2013

“…Plant internal synthesis of NO is suggested to originate either from nitrate ( del Rio et al, 2004; Palavan‐Unsal and Arisan , 2009) or arginine ( Palavan‐Unsal and Arisan , 2009), but can also be induced by elicitors of defense responses ( Besson‐Bard et al, 2008). Only recently it has been shown that soil NO also influences the N uptake of the roots of deciduous and coniferous seedlings ( Simon et al, 2009, 2013), indicating the significant role of NO in plant N acquisition.…”

“…Furthermore, in experiments under controlled conditions, N uptake of beech and Scots pine seedlings was strongly affected by soil NO concentration, suggesting that NO is involved in the regulation of plant N uptake. However, N uptake of roots differed between species and was also influenced by soil N availability, N source, and rhizospheric CO 2 concentration ( Simon et al, 2009, 2013; Dong et al, 2015). In a study with beech seedlings, Simon et al (2009) found that high concentrations of soil NO increased the uptake of ammonium and glutamine‐N compared to ambient NO levels.…”

“…However, N uptake of roots differed between species and was also influenced by soil N availability, N source, and rhizospheric CO 2 concentration ( Simon et al, 2009, 2013; Dong et al, 2015). In a study with beech seedlings, Simon et al (2009) found that high concentrations of soil NO increased the uptake of ammonium and glutamine‐N compared to ambient NO levels. In contrast, nitrate and glutamine‐N uptake was enhanced in Scots pine seedlings at high soil compared to ambient NO concentration ( Simon et al, 2013).…”

“…The mechanisms involved in these interactions of soil NO with N uptake by plant roots are not well understood. Only a study using beech seedlings indicates that elevated soil NO concentrations do not regulate N uptake at the level of gene expression ( Simon et al, 2009). Furthermore, the few studies focused on the effects of NO on seedlings under controlled conditions.…”