Abstract
Wheat is one of the most important food crops in the world, its availability affects global food security. In this study, we investigated variations in NH4+ and NO3- fluxes in the fine roots of wheat using a scanning ion-selective electrode technique in the presence of different nitrogen (N) forms, N concentrations, and pH levels as well as under water stress. Our results show that the fine roots of wheat demonstrated maximum NH4+ and NO3− influxes at 20 mm and 25 mm from the root tip, respectively. The maximal net NH4+ and NO3− influxes were observed at pH 6.2 in the presence of a 1/4 N solution. We observed N efflux in two different cultivars following the exposure of roots to a 10% PEG-6000 solution. Furthermore, the drought-tolerant cultivar generally performed better than the drought-intolerant cultivar. Net NH4+ and NO3− fluxes may be determined by plant growth status, but environmental conditions can also affect the magnitude and direction of N flux. Interestingly, we found that NO3− was more sensitive to environmental changes than NH4+. Our results may be used to guide future hydroponic experiments in wheat as well as to aid in the development of effective fertilisation protocols for this crop.
Highlights
Net ammonium and nitrate fluxes in wheat roots under different environmental conditions as assessed by scanning ion-selective electrode technique
The elucidation of the mechanisms associated with N transport by evaluating net N flux is challenging
Net N flux is based on the sum of N influx and efflux, and it is influenced by the rates of assimilation and compartmentalisation[27]
Summary
Net ammonium and nitrate fluxes in wheat roots under different environmental conditions as assessed by scanning ion-selective electrode technique. To enable the performance of a variety of functions, the root system is composed of anatomically, morphologically and physiologically distinct root types that demonstrate a high degree of plasticity in terms of their responses to external signals and adaptation to heterogeneous nutrient supplies[3,4]. These anatomical and physiological complexities often determine the NH41 and NO32 absorption capacity of the root. Luo, et al.[1] have demonstrated marked spatial variability in NH41 and NO32 fluxes in the roots of the woody plant species Populus popularis
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have