The CO2 fertilization effect on leaf photosynthesis of maize (Zea mays L.) depends on growth temperatures with changes in leaf anatomy and soluble sugars

Abstract

Understanding the potential mechanisms and processes of leaf photosynthesis in response to elevated CO2 concentration ([CO2]) and temperature is critical for estimating the impacts of climatic change on the growth and yield in crops such as maize (Zea mays L.), which is a widely cultivated C4 crop all over the world. We examined the combined effect of elevated [CO2] and temperature on plant growth, leaf photosynthesis, stomatal traits, and biochemical compositions of maize with six environmental growth chambers controlling two CO2 levels (400 and 800 μmol mol−1) and three temperature regimes (25/19°C, 31/25°C, and 37/31°C). We found that leaf photosynthesis was significantly enhanced by increasing growth temperature from 25/19°C to 31/25°C independent of [CO2]. However, leaf photosynthesis drastically declined when the growth temperature was continually increased to 37/31°C at both ambient CO2 concentration (400 μmol mol−1, a[CO2]) and elevated CO2 concentration (800 μmol mol−1, e[CO2]). Meanwhile, we also found strong CO2 fertilization effect on maize plants grown at the highest temperature (37/31°C), as evidenced by the higher leaf photosynthesis at e[CO2] than that at a[CO2], although leaf photosynthesis was similar between a[CO2] and e[CO2] under the other two temperature regimes of 25/19°C and 31/25°C. Furthermore, we also found that e[CO2] resulted in an increase in leaf soluble sugar, which was positively related with leaf photosynthesis under the high temperature regime of 37/31°C (R2 = 0.77). In addition, our results showed that e[CO2] substantially decreased leaf transpiration rates of maize plants, which might be partially attributed to the reduced stomatal openness as demonstrated by the declined stomatal width and stomatal area. These results suggest that the CO2 fertilization effect on plant growth and leaf photosynthesis of maize depends on growth temperatures through changing stomatal traits, leaf anatomy, and soluble sugar contents.

Elevated CO2 ameliorates the high temperature stress effects on physio-biochemical, growth, yield traits of maize hybrids

“…The release of sugars and other derived metabolites serves to support plant growth under stress and acts as osmo-protectants to alleviate the negative effects of the stress 88 . However, the starch and soluble sugars content were not significantly affected in maize with moderate level of temperature rise and eCO 2 , but was significantly affected when the temperature was above the threshold level 89 . In our study, we observed higher accumulation of soluble sugars and starch content under eT and eT + eCO 2 in comparison to ambient condition and there was also variation between the hybrids.…”

Climate change increases net CO 2 assimilation in the leaves of strawberry, but not yield

“…The relationship between net CO 2 assimilation and CO 2 is described by A/C i or A/C c curves (Coursolle et al, 2019;Moualeu-Ngangue et al, 2016;Zeng et al, 2010;Zhou et al, 2019). The response to high CO 2 varies across species and ecosystems and with light and temperature (Hu et al, 2022;Kabir et al, 2023;Liu et al, 2022;Mndela et al, 2022;Wullschleger, 1993). Poorter et al (2022) conducted a meta-analysis of the response of C 3 plants to CO 2 across 630 experiments.…”

Interactive Effect of Elevated Carbon Dioxide, Temperature and Nitrogen on the Growth Parameters of Rice at Active Tillering Stage

“…Leaf area is a fundamental measure of the conversion of light energy to chemical energy in plant leaves. Many researchers from different part of the world [30][31][32] found that increase in [CO2] concentration increased the growth parameters due to [CO2] fertilization effect.…”