Growth in elevated CO₂ protects photosynthesis against high‐temperature damage

Abstract

We present evidence that plant growth at elevated atmospheric CO 2 increases the high-temperature tolerance of photosynthesis in a wide variety of plant species under both greenhouse and field conditions. We grew plants at ambient CO 2 (~360 mmol mol -1 ) and elevated CO 2 (550-1000 mmol mol -1 ) in three separate growth facilities, including the Nevada Desert Free-Air Carbon Dioxide Enrichment (FACE) facility. Excised leaves from both the ambient and elevated CO 2 treatments were exposed to temperatures ranging from 28 to 48 °C. In more than half the species examined (4 of 7, 3 of 5, and 3 of 5 species in the three facilities), leaves from elevated CO 2 -grown plants maintained PSII efficiency (F v /F m ) to significantly higher temperatures than ambient-grown leaves. This enhanced PSII thermotolerance was found in both woody and herbaceous species and in both monocots and dicots. Detailed experiments conducted with Cucumis sativus showed that the greater F v /F m in elevated versus ambient CO 2 -grown leaves following heat stress was due to both a higher F m and a lower F o , and that F v /F m differences between elevated and ambient CO 2 -grown leaves persisted for at least 20 h following heat shock. Cucumis sativus leaves from elevated CO 2 -grown plants had a critical temperature for the rapid rise in F o that averaged 2·9 °C higher than leaves from ambient CO 2 -grown plants, and maintained a higher maximal rate of net CO 2 assimilation following heat shock. Given that photosynthesis is considered to be the physiological process most sensitive to high-temperature damage and that rising atmospheric CO 2 content will drive temperature increases in many already stressful environments, this CO 2 -induced increase in plant high-temperature tolerance may have a substantial impact on both the productivity and distribution of many plant species in the 21st century.

Seasonal variations and acclimation potential of the thermostability of photochemistry in four Mediterranean conifers

“…Although the ability of T c and thermostability of photosynthesis to acclimate and therefore to display an important phenotypic plasticity is now well recognised, experimental data quantifying the amplitude of long term responses are still seldom. Growth under high CO 2 concentrations (750 vs. 350 µmol mol -1 ) led to an increase of T c by 2.4°C [37]. Similarly, drought resulted in a 8°C increase of T c in Quercus suber [11].…”

“…A moderate drought stress increased significantly the thermostability in a range of species like Cedrus atlantica [7,8,23] or Triticum sativum [27] and exogenous abscisic acid (ABA) increased PS II termostability in barley [19] and in cucumber [25]. Finally, increased CO 2 resulted also in a larger thermostability of the photosynthetic apparatus [37].…”

Can barley (Hordeum vulgare L. s.l.) adapt to fast climate changes? A controlled selection experiment

“…Crop yields are predicted to decrease under increased climatic stress (Taub et al 2000), why the adaptive capacity of crop genotypes needs to be explored to select suitable lines for breeding towards stress tolerance. The use of environmentally tailored genotypes is one of the measures that can be applied to secure a primary production providing for a growing world population with minimum costs to the environment (Araus et al 2008).…”

“…The use of environmentally tailored genotypes is one of the measures that can be applied to secure a primary production providing for a growing world population with minimum costs to the environment (Araus et al 2008). The globe is facing an increase in temperature, elevated atmospheric carbon dioxide and other greenhouse gases (Taub et al 2000;Prasad et al 2002;IPCC 2007). If radical decreases in greenhouse gasses are not achieved, the global mean temperature may incase about 4.0°C [degrees Celsius; likely range: 2.4-6.4°C (IPCC 2007)] within this century.…”

Profiling of Indoor Plant to Deteriorate Carbon Dioxide Using Low Light Intensity

“…High temperature is usually stress for plants, restricting growth, and will damage the photosynthetic system [21]. Whilst, low temperature also makes the plant in photoinhibition condition, limiting the productivity and geographical distribution of many species, including important agricultural crops [22,23].…”