Effects of elevated CO₂ on grain yield and quality of wheat: results from a 3‐year free‐air CO₂ enrichment experiment

Abstract

Spring wheat (Triticum aestivum L. cv. TRISO) was grown for three consecutive seasons in a free‐air carbon dioxide (CO2) enrichment (FACE) field experiment in order to examine the effects on crop yield and grain quality. CO2 enrichment promoted aboveground biomass (+11.8%) and grain yield (+10.4%). However, adverse effects were predominantly observed on wholegrain quality characteristics. Although the thousand‐grain weight remained unchanged, size distribution was significantly shifted towards smaller grains, which may directly relate to lower market value. Total grain protein concentration decreased significantly by 7.4% under elevated CO2, and protein and amino acid composition were altered. Corresponding to the decline in grain protein concentration, CO2 enrichment resulted in an overall decrease in amino acid concentrations, with greater reductions in non‐essential than essential amino acids. Minerals such as potassium, molybdenum and lead increased, while manganese, iron, cadmium and silicon decreased, suggesting that adjustments of agricultural practices may be required to retain current grain quality standards. The concentration of fructose and fructan, as well as amounts per area of total and individual non‐structural carbohydrates, except for starch, significantly increased in the grain. The same holds true for the amount of lipids. With regard to mixing and rheological properties of the flour, a significant increase in gluten resistance under elevated CO2 was observed. CO2 enrichment obviously affected grain quality characteristics that are important for consumer nutrition and health, and for industrial processing and marketing, which have to date received little attention.

Impact of Elevated CO<sub>2</sub> on Wheat Growth and Yield under Free Air CO<sub>2</sub> Enrichment

“…Apart from this, elevated CO 2 (eCO 2 ) is also known to directly alter grain yield and quality of important agricultural crops such as wheat [2] [3]. Many studies have reported altered protein content and nutritional value of wheat seed as affected by eCO 2 .…”

“…Many studies have reported altered protein content and nutritional value of wheat seed as affected by eCO 2 . Some demonstrated decrease of total grain protein concentration by 3.5% -14.3% [4] [5] while others reported altered protein composition [2] [6].…”

“…Many studies have reported altered protein content and nutritional value of wheat seed as affected by eCO 2 . Some demonstrated decrease of total grain protein concentration by 3.5% -14.3% [4] [5] while others reported altered protein composition [2] [6]. The reported changes in the grain quality under eCO 2 condition could, in future, result in a need for a dietary counter-balancing with other food protein compounds or fortification to provide the required nutrients for an adequate human nutrition.…”

“…Turnover of the net carbon from primary production to the soil via root exudates is based on the concentration of the CO 2 in the atmosphere. Recent studies have revealed only minor changes in soil microbial communities under eCO 2 [8]. But it is important to understand microbial response to increasing (CO 2 ) to predict its effects on soil as plant-associated microbes produce plant hormones, fix nitrogen, and oxidize methane [9].…”

MODERN OPPORTUNITIES FOR IMPROVING QUALITY OF BAKERY PRODUCTS VIA REALIZING THE BREAD WHEAT GENETIC POTENTIAL-BY-ENVIRONMENT INTERACTIONS (review)

“…In a number of countries, its influence on the formation of technological properties of flour and dough is studied [25,[43][44][45]. In some studies, besides properties, the changes in the grain proteome under the action of elevated CO 2 concentration have been assessed [45,46].…”