Nitrogen nutrition and aspects of root growth and function of two wheat cultivars under elevated [CO2]

Abstract

Highlights  Wheat cultivars increased either root growth or specific root N uptake at low soil N  Wheat can utilise nitrate, ammonium, or glutamine as N source in the field  Specific root uptake capacity for ammonium was different between cultivars  Root growth but not specific root N uptake capacity was linked to greater grain N  Elevated CO2 decreased grain N of both cultivars and did not affect uptake capacities

Elevated [CO2] effects on crops: Advances in understanding acclimation, nitrogen dynamics and interactions with drought and other organisms

“…Nitrogen uptake under e[CO 2 ] is strongly correlated with biomass stimulation, indicating the dependence of nutrient foraging on whole‐plant sink strength (Tausz et al . 2017a). The relative magnitude of the CO 2 response varies greatly across studies, with some suggesting unchanged ( e.g .…”

“…The effect of CO 2 on N uptake and biomass stimulation ranged from negative to highly positive, potentially reflecting the high plasticity of that particular cultivar to adapt to seasonal trends (Tausz et al . 2017a). There was no indication that total in‐season water supply influenced the magnitude of the response (solid versus open symbols), thus timing of in‐season rainfall, differences in stored soil water and/or temperature might have driven the results (Fig.…”

“…; Tausz et al . 2017a; Houshmandfar et al . ) at three different developmental stages ( DC 30/31, DC 65 and DC 90; Zadoks et al .…”

“…), such a step decrease in leaf [N] seems to be quite conserved across environmental conditions or even N application rates in FACE experiments, as shown for wheat (Tausz et al . 2017a; Dier et al . ).…”

“…So far little is known about the effect of e[CO 2 ] on transporters, but a recent study by Tausz et al . (2017a), using a 15 N label method on intact roots under FACE, found no evidence that specific root uptake capacity for nitrate, ammonium or glutamine (used as a model organic N source) was affected by e[CO 2 ]. They concluded that N uptake strategies were unrelated to changes in grain or biomass [N] at the investigated field site.…”