posted on 2020-03-10, 14:25authored byMarkus Dier, Liane Hüther, Waltraud X. Schulze, Martin Erbs, Peter Köhler, Hans-Joachim Weigel, Remy Manderscheid, Christian Zörb
Elevated atmospheric CO2 concentrations (e[CO2]) can decrease the grain quality
of wheat. However, little information
exists concerning interactions between e[CO2] and nitrogen
fertilization on important grain quality traits. To investigate this,
a 2-year free air CO2 enrichment (FACE) experiment was
conducted with two CO2 (393 and 600 ppm) and three (deficiency,
adequate, and excess) nitrogen levels. Concentrations of flour proteins
(albumins/globulins, gliadins, and glutenins) and key minerals (iron,
zinc, and sulfur) and baking quality (loaf volume) were markedly increased
by increasing nitrogen levels and varied between years. e[CO2] resulted in slightly decreased albumin/globulin and total gluten
concentration under all nitrogen conditions, whereas loaf volume and
mineral concentrations remained unaffected. Two-dimensional gel electrophoresis
revealed strong effects of nitrogen supply and year on the grain proteome.
Under adequate nitrogen, the grain proteome was affected by e[CO2] with 19 downregulated and 17 upregulated protein spots.
The downregulated proteins comprised globulins but no gluten proteins.
e[CO2] resulted in decreased crude protein concentration
at maximum loaf volume. The present study contrasts with other FACE
studies showing markedly stronger negative impacts of e[CO2] on chemical grain quality, and the reasons for that might be differences
between genotypes, soil conditions, or the extent of growth stimulation
by e[CO2].