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How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

Niinemets Ü, Sun Z - J. Exp. Bot. (2014)

Bottom Line: The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions.Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply.In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants.

View Article: PubMed Central - PubMed

Affiliation: Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia ylo.niinemets@emu.ee.

No MeSH data available.


Related in: MedlinePlus

Relationships of the optimum temperature for isoprene emission (Eq. 4) with the relative increase of isoprene emission rate (I) with increasing temperature from 30 to 50 °C (Eq. 2) in hybrid aspen leaves grown under two different CO2 concentrations (ambient vs elevated) and measured at different ambient CO2 concentrations of 380 and 780 μmol mol–1, and at different light intensities of 500 and 2000 μmol m–2 s–1 (symbols for different light intensities not shown separately). Separate regression lines were fitted to the data from different growth CO2 treatments (P<0.05 for the growth CO2 effect according to a common-slope ANCOVA model). Table 1 shows a comparison of average Topt values at different growth and measurement [CO2] conditions.
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Figure 3: Relationships of the optimum temperature for isoprene emission (Eq. 4) with the relative increase of isoprene emission rate (I) with increasing temperature from 30 to 50 °C (Eq. 2) in hybrid aspen leaves grown under two different CO2 concentrations (ambient vs elevated) and measured at different ambient CO2 concentrations of 380 and 780 μmol mol–1, and at different light intensities of 500 and 2000 μmol m–2 s–1 (symbols for different light intensities not shown separately). Separate regression lines were fitted to the data from different growth CO2 treatments (P<0.05 for the growth CO2 effect according to a common-slope ANCOVA model). Table 1 shows a comparison of average Topt values at different growth and measurement [CO2] conditions.

Mentions: To gain insight into the sources of variation in Topt, we also analysed the correlations of Topt with temperature response curve parameters (Eq. 3) and with traits characterizing the temperature sensitivity of emissions to lower and higher temperatures (Q10 and RT, Eq. 2). As isoprene synthase itself has a very high optimum temperature of around 50 ºC (Monson et al., 1992; Lehning et al., 1999; Rasulov et al., 2010), lower Topt values than those for isoprene synthase suggest limitation of isoprene synthesis by the DMADP pool size (Rasulov et al., 2010). Accordingly, variation in Topt at a given measurement [CO2] and light level should reflect differences in the heat-dependent decay of the DMADP pool size. Topt was positively correlated with a relative increase of isoprene emission rate at 50 °C (RT, Eq. 2; Fig. 3). In this relationship, the interaction terms, RT×(growth [CO2]) (P>0.1), RT×(light intensity) (P>0.6) and RT×(measurement [CO2]) (P>0.7) were not statistically significant. According to the common-slope ANCOVA model, both light intensity (P<0.03, Table 1), and growth [CO2] (P<0.05, Fig. 3) were statistically significant factors, implying that Topt was lower at a given RT both at higher measurement light and in elevated-[CO2]-grown plants (Fig. 3), suggesting a greater control by the DMADP pool size.


How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

Niinemets Ü, Sun Z - J. Exp. Bot. (2014)

Relationships of the optimum temperature for isoprene emission (Eq. 4) with the relative increase of isoprene emission rate (I) with increasing temperature from 30 to 50 °C (Eq. 2) in hybrid aspen leaves grown under two different CO2 concentrations (ambient vs elevated) and measured at different ambient CO2 concentrations of 380 and 780 μmol mol–1, and at different light intensities of 500 and 2000 μmol m–2 s–1 (symbols for different light intensities not shown separately). Separate regression lines were fitted to the data from different growth CO2 treatments (P<0.05 for the growth CO2 effect according to a common-slope ANCOVA model). Table 1 shows a comparison of average Topt values at different growth and measurement [CO2] conditions.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4321546&req=5

Figure 3: Relationships of the optimum temperature for isoprene emission (Eq. 4) with the relative increase of isoprene emission rate (I) with increasing temperature from 30 to 50 °C (Eq. 2) in hybrid aspen leaves grown under two different CO2 concentrations (ambient vs elevated) and measured at different ambient CO2 concentrations of 380 and 780 μmol mol–1, and at different light intensities of 500 and 2000 μmol m–2 s–1 (symbols for different light intensities not shown separately). Separate regression lines were fitted to the data from different growth CO2 treatments (P<0.05 for the growth CO2 effect according to a common-slope ANCOVA model). Table 1 shows a comparison of average Topt values at different growth and measurement [CO2] conditions.
Mentions: To gain insight into the sources of variation in Topt, we also analysed the correlations of Topt with temperature response curve parameters (Eq. 3) and with traits characterizing the temperature sensitivity of emissions to lower and higher temperatures (Q10 and RT, Eq. 2). As isoprene synthase itself has a very high optimum temperature of around 50 ºC (Monson et al., 1992; Lehning et al., 1999; Rasulov et al., 2010), lower Topt values than those for isoprene synthase suggest limitation of isoprene synthesis by the DMADP pool size (Rasulov et al., 2010). Accordingly, variation in Topt at a given measurement [CO2] and light level should reflect differences in the heat-dependent decay of the DMADP pool size. Topt was positively correlated with a relative increase of isoprene emission rate at 50 °C (RT, Eq. 2; Fig. 3). In this relationship, the interaction terms, RT×(growth [CO2]) (P>0.1), RT×(light intensity) (P>0.6) and RT×(measurement [CO2]) (P>0.7) were not statistically significant. According to the common-slope ANCOVA model, both light intensity (P<0.03, Table 1), and growth [CO2] (P<0.05, Fig. 3) were statistically significant factors, implying that Topt was lower at a given RT both at higher measurement light and in elevated-[CO2]-grown plants (Fig. 3), suggesting a greater control by the DMADP pool size.

Bottom Line: The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions.Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply.In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants.

View Article: PubMed Central - PubMed

Affiliation: Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia ylo.niinemets@emu.ee.

No MeSH data available.


Related in: MedlinePlus