Rising CO₂ from historical concentrations enhances the physiological performance of Brassica napus seedlings under optimal water supply but not under reduced water availability

Abstract

The productivity of many important crops is significantly threatened by water shortage, and the elevated atmospheric CO can significantly interact with physiological processes and crop responses to drought. We examined the effects of three different CO concentrations (historical ~300 ppm, ambient ~400 ppm and elevated ~700 ppm) on physiological traits of oilseed rape (Brassica napus L.) seedlings subjected to well-watered and reduced water availability. Our data show (1) that, as expected, increasing CO level positively modulates leaf photosynthetic traits, leaf water-use efficiency and growth under non-stressed conditions, although a pronounced acclimation of photosynthesis to elevated CO occurred; (2) that the predicted elevated CO concentration does not reduce total evapotranspiration under drought when compared with present (400 ppm) and historical (300 ppm) concentrations because of a larger leaf area that does not buffer transpiration; and (3) that accordingly, the physiological traits analysed decreased similarly under stress for all CO concentrations. Our data support the hypothesis that increasing CO concentrations may not significantly counteract the negative effect of increasing drought intensity on Brassica napus performance.

Increased CO2 and light intensity regulate growth and leaf gas exchange in tomato

“…There are many routes through which increased CO 2 and light intensity may regulate Pn. These include effects on leaf pigments (Pérez‐López et al ), leaf mineral content (Li et al ), water use (Lanoue et al ) and Calvin cycle enzyme activity (Yu and Wang ), AQY and CE (Faralli et al , Jiang et al ). Potentially, all these result in higher dry mass accumulations and therefore faster growth (Li et al ).…”

Different ways to die in a changing world: Consequences of climate change for tree species performance and survival through an ecophysiological perspective

“…In view of this increase in performance and productivity promoted by high [CO 2 ], even in the presence of abiotic stresses, should we really be concerned about the dynamics of the distribution and survival of forest species under a climate change scenario? The answer to this question is extremely complex because the beneficial effects of high [CO 2 ] found in some studies (Drake et al, 2011;Idso & Kimbal, 1997;Oliveira et al, 2016;Pérez-Jiménez, Hernández-Munuera, Piñero, López-Ortega, & del Amor, 2018;Radoglou & Jarvis, 1990;Rodrigues et al, 2016;Roy et al, 2016;Swann et al, 2016;Yu et al, 2014) are in direct contrast to the results of several other reports (Calvo et al, 2017;Clark, Clark, & Oberbauer, 2010;Faralli et al, 2017;Feeley, Joseph Wright, Nur Supardi, Kassim, & Davies, 2007;Voelker et al, 2017).…”

“…One of the most significant effects of the increase in [CO 2 ] is the enhancement of the photosynthetic process, especially in C3 plants (Ainsworth & Long, ; Bader, Siegwolf, & Körner, ; Drake & Leadley, ; Faralli, Grove, Hare, Kettlewell, & Fiorani, ; Idso & Kimbal, ; Rey & Jarvis, ; Streit, Siegwolf, Hagedorn, Schaub, & Buchmann, ; Tissue, Thomas, & Strain, ; Yang et al, ). This fertilizer effect of CO 2 has been attributed to an increase in the carboxylase activity and a reduction in the oxygenase activity of Rubisco due to the greater relative proportion of CO 2 to O 2 within chloroplasts (Ainsworth & Rogers, ; Rodrigues et al, ).…”

“…As a result, increased [CO 2 ] tends to significantly reduce photorespiratory metabolism (Drake, Gonzàlez‐Meler, & Long, ), which helps to explain the increase in growth rates observed in certain species. This increased [CO 2 ] at Rubisco carboxylation sites also allows higher rates of A to be achieved at lower g s , resulting in reduced consumption of water per molecule of carbon fixed and therefore higher water use efficiency (WUE; Faralli et al, ; Franks, ; van der Sleen et al, ; Streit et al, ) (Figure ). Together, the reduction in photorespiratory activity and the increase in WUE, induced by higher [CO 2 ], have the potential to minimize the deleterious effects of certain abiotic stresses.…”

Collaborative Innovation of Low-Carbon Technology from the Triple Helix Perspective: Exploring Critical Success Factors Based on DEMATEL-ISM

“…Addressing climate change is an inherent need for China's sustainable development. Before the start of the first industrial revolution, the concentration of carbon dioxide in the air was below 300 ppm (or parts per million, which represents the average number of carbon dioxide molecules in a million air molecules) [2]. As can be seen from Fig.…”