Influence of Ozone Stress on Soybean Response to Carbon Dioxide Enrichment: III. Yield and Seed Quality

Abstract

Ozone in the troposphere can cause plant stress, whereas elevated CO. generally causes positive responses. Little is known of how these gases interact to affect plant response. Interactive effects on yield and seed quality of soybean [Glycine max (L.) Merr.] grown in 14-L pots were measured in open-top field chambers. Essex was tested in 1993, and Essex, Holladay, and NK 6955 were tested in 1994. Plants were exposed from emergence to maturity to four CO; levels (ambient and 1.3,1.6, and 2.0 times ambient) and three O, levels (0.4, 0.9, and 1.5 times ambient) in 12 combinations. Increasing O, suppressed growth and yield, whereas CO, enrichment stimulated growth and yield. Carbon dioxide-induced stimulation was greater for plants stressed by O, than for non stressed plants. For example, CO 2 at 2.0 times ambient increased 2-yr mean seed yield of Essex by 16, 24, and 81% at O, levels of 0.4, 0.9, and 1.5 times ambient, respectively. Effects of O, and CO, on seed oil content were variable with numerous cultivar differences. Seed protein content was never affected. Elevated O, suppressed oleic acid content in seeds, whereas CO, increased it; the nature of the O, x CO 2 interaction for oleic acid was similar to that observed for most yield measures. Carbon dioxide-induced stimulation of plants stressed by O, was apparently caused partly by amelioration of O 3 stress. Interactions between O 3 and CO 2 must be considered for proper interpretation of cause-effect relationships in CO, enrichment studies.

Rising atmospheric carbon dioxide on grain quality in crop plants

“…For example, oleic acid concentration increased with increasing temperatures while linoleic acid decreased (Carver et al 1986;Rennie and Tanner 1989;Rebetzke et al 1996). Heagle et al (1998) observed a positive, significant effect of CO 2 enrichment on soybean seed oil and oleic acid concentration.…”

“…Phosphorus concentration in seed was also increased and 50% of this phosphorus in soybean is in phytate form. Heagle et al (1998) found a significant effect of elevated CO 2 on soybean oil in cultivars Essex, Holladay and NK6955. The oleic acid concentration was positively affected by CO 2 and the effect of cultivar was also highly significant.…”

Elevated concentrations of atmospheric CO2 protect against and compensate for O3 damage to photosynthetic tissues of field‐grown wheat

“…However, the individual effects of these pollutants on crop growth and yield are not simply additive in combined exposures (Barnes & Pfirrmann, 1992 ;Mulchi et al, 1992 ;Reinert & Ho, 1995 ;Fiscus et al, 1997 ;McKee et al, 1997a ;Mulholland et al, 1997a ;Heagle et al, 1998).…”

Effects of Drought and Elevated Atmospheric Carbon Dioxide on Seed Nutrition and 15N and 13C Natural Abundance Isotopes in Soybean Under Controlled Environments

“…However, results of the effects of elevated CO 2 on seed composition are still conflicting. For example, small effects of elevated CO 2 on seed composition were found [40], whereas others found a significant effect of elevated CO 2 on soybean seed oil in cultivars Essex, Holladay, and NK6955 [41]. The authors also found that oleic fatty acid concentration was positively affected and protein concentration was not affected by CO 2 .…”