Effects of Elevated CO2 and O3 on Phenolic Compounds in Spring Wheat and Maize Leaves

Abstract

C(3) crops are generally considered more sensitive than C(4) crops to the elevated CO(2) and O(3), but it is unclear whether the concentrations of phenolic compounds in them are affected. In this paper, an enrichment experiment with open-top chamber was conducted to examine the effects of elevated CO(2), O(3), and their combination on the contents of total phenolic compounds and flavone in the leaves of spring wheat (C(3) crop) and maize (C(4) crop). The results showed for spring wheat, the total phenolic contents in its leaves at jointing stage was significantly higher under elevated CO(2) and/or O(3), with the sequence of CO(2) plus O(3) > O(3) > CO(2) > ambient, while at grain-filling stage, the total phenolic content was lower under CO(2) plus O(3) than under CO(2), O(3), and ambient. The total phenolic content in maize leaves at jointing stage had the similar variation trend with that for wheat, but at grain-filling stage, the total phenolic content was slightly affected by elevated CO(2) and/or O(3). The flavone content in spring wheat leaves was significantly lower under CO(2) and/or O(3) stress at jointing stage, but had lesser difference at grain-filling stage under the stress. The same variation trend was observed in the flavone content in maize leaves at jointing and grainfilling stages, i.e., CO(2) plus O(3) > CO(2) > ambient > O(3). C(3) plant was more sensitive than C(4) plant to the CO(2) and/or O(3) stress.

Annual ryegrass (Lolium rigidum Gaud) competition altered wheat grain quality: A study under elevated atmospheric CO2 levels and drought conditions

“…This is attributed to the amount of substrate available to biosynthesise of phenolic compounds (Bustos, Riegel & Calderini, 2012). Phenolic content was not affected by annual ryegrass competition at both well-watered and drought conditions under e[CO 2 ], in agreement with previous research on phenolic content of wheat leaves (Li, Shi & Chen, 2008).…”

Elevated CO2 Impact on Common Wheat (Triticum aestivum L.) Yield, Wholemeal Quality, and Sanitary Risk

“…The enrichment with [CO 2 ] may differentially affect the content of phenolic compounds in cereal leaves. Li et al observed an increase in total phenolics of wheat and maize leaves at e­[CO 2 ] during both the vegetative and the ripening stage. As far as antioxidants of rice grains are concerned, both free and bound phenolic compounds were negatively affected by e­[CO 2 ] .…”

Effect of the Ozone Application in the Nutrient Solution and the Yield and Oxidative Stress of Hydroponic Baby Red Chard

“…There are reports of increases in phenolic compounds in response to increased atmospheric O 3 , as in the case of red clover (Trifolium pratense L.), whose total phenolic compounds increased between 5 and 12% with concentrations of 0.038 and 0.056 mg•L −1 of O 3 (range 1.26 times above ambient O 3 ) [59]. In wheat (Triticum aestivum L.) exposed to 0.384 mg•L −1 of O 3 , an increase in phenol content was also observed; however, this increase depended on the phenological stage of the crop, being higher at the grainfilling stage than during vegetative growth [60]. In another study of red lettuce grown under artificial light, the total phenolics, flavonoids, and anthocyanins showed a significant increase after 0.25 h of exposition on the fourth leaf [61].…”