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Temperature Shift Experiments Suggest That Metabolic Impairment and Enhanced Rates of Photorespiration Decrease Organic Acid Levels in Soybean Leaflets Exposed to Supra-Optimal Growth Temperatures.

Sicher RC - Metabolites (2015)

Bottom Line: In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C.Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures.Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

View Article: PubMed Central - PubMed

Affiliation: Crop Systems and Global Change Laboratory, United States Department of Agriculture-Agricultural Research Service, Room 332, Bldg. 001, BARC-west 10300 Baltimore Avenue, Beltsville, MD 20705, USA. richard.sicher@ars.usda.gov.

ABSTRACT
Elevated growth temperatures are known to affect foliar organic acid concentrations in various plant species. In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Temperature effects on the above mentioned organic acids were partially reversed three days after plants were transferred among optimal and supra-optimal growth temperatures. In addition, CO2 enrichment increased foliar malate, malonate and fumarate concentrations in the supra-optimal temperature treatment, thereby mitigating effects of high temperature on respiratory metabolism. Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures. The above findings suggested that diminished levels of organic acids in soybean leaflets upon exposure to high growth temperatures were attributable to metabolic impairment and to changes of photorespiratory flux. Leaf development rates differed among temperature and CO2 treatments, which affected foliar organic acid levels. Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

No MeSH data available.


Related in: MedlinePlus

Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets under elevated CO2 (70 Pa). Experimental details and symbols were as in Figure 1.
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metabolites-05-00443-f002: Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets under elevated CO2 (70 Pa). Experimental details and symbols were as in Figure 1.

Mentions: It was previously shown that CO2 enrichment mitigated the effects of the above optimal growth temperatures on organic acid levels in soybean leaflets (Sicher, 2013). In the current study, citrate and malate (Figure 2A,B) were 54 and 32% lower, respectively, in response to elevated growth temperatures when plants were grown with elevated CO2 (70 Pa). Levels of both of these metabolites were greater when grown at 36/28 °C when comparing plants in the elevated to the ambient CO2 treatment. As above, these values were obtained by averaging data for the continuous temperature treatments across all four harvest dates. This result confirmed that the effects of high temperature growth conditions on leaflet concentrations of organic acids were lower in elevated than in ambient CO2. In contrast to plants grown with ambient CO2, changes of foliar malonate and fumarate in response to elevated growth temperatures were not observed in the 70 Pa CO2 treatment (Figure 2C,D,F). Succinate differed among growth temperature treatments when plants were exposed to enhanced CO2, although this was mostly evident on the first and second harvests (Figure 2E).


Temperature Shift Experiments Suggest That Metabolic Impairment and Enhanced Rates of Photorespiration Decrease Organic Acid Levels in Soybean Leaflets Exposed to Supra-Optimal Growth Temperatures.

Sicher RC - Metabolites (2015)

Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets under elevated CO2 (70 Pa). Experimental details and symbols were as in Figure 1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588805&req=5

metabolites-05-00443-f002: Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets under elevated CO2 (70 Pa). Experimental details and symbols were as in Figure 1.
Mentions: It was previously shown that CO2 enrichment mitigated the effects of the above optimal growth temperatures on organic acid levels in soybean leaflets (Sicher, 2013). In the current study, citrate and malate (Figure 2A,B) were 54 and 32% lower, respectively, in response to elevated growth temperatures when plants were grown with elevated CO2 (70 Pa). Levels of both of these metabolites were greater when grown at 36/28 °C when comparing plants in the elevated to the ambient CO2 treatment. As above, these values were obtained by averaging data for the continuous temperature treatments across all four harvest dates. This result confirmed that the effects of high temperature growth conditions on leaflet concentrations of organic acids were lower in elevated than in ambient CO2. In contrast to plants grown with ambient CO2, changes of foliar malonate and fumarate in response to elevated growth temperatures were not observed in the 70 Pa CO2 treatment (Figure 2C,D,F). Succinate differed among growth temperature treatments when plants were exposed to enhanced CO2, although this was mostly evident on the first and second harvests (Figure 2E).

Bottom Line: In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C.Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures.Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

View Article: PubMed Central - PubMed

Affiliation: Crop Systems and Global Change Laboratory, United States Department of Agriculture-Agricultural Research Service, Room 332, Bldg. 001, BARC-west 10300 Baltimore Avenue, Beltsville, MD 20705, USA. richard.sicher@ars.usda.gov.

ABSTRACT
Elevated growth temperatures are known to affect foliar organic acid concentrations in various plant species. In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Temperature effects on the above mentioned organic acids were partially reversed three days after plants were transferred among optimal and supra-optimal growth temperatures. In addition, CO2 enrichment increased foliar malate, malonate and fumarate concentrations in the supra-optimal temperature treatment, thereby mitigating effects of high temperature on respiratory metabolism. Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures. The above findings suggested that diminished levels of organic acids in soybean leaflets upon exposure to high growth temperatures were attributable to metabolic impairment and to changes of photorespiratory flux. Leaf development rates differed among temperature and CO2 treatments, which affected foliar organic acid levels. Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

No MeSH data available.


Related in: MedlinePlus