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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 grown with ambient CO2 partial pressures. Plants were grown from seeds using continuous growth temperatures of 28/20 °C (●—●) or 36/28 °C (○—○). The first 21 or 22 DAS selected plants were transferred from the higher to lower (∆-----∆) or from the lower to higher (▼-----▼) growth treatment.
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metabolites-05-00443-f001: Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets grown with ambient CO2 partial pressures. Plants were grown from seeds using continuous growth temperatures of 28/20 °C (●—●) or 36/28 °C (○—○). The first 21 or 22 DAS selected plants were transferred from the higher to lower (∆-----∆) or from the lower to higher (▼-----▼) growth treatment.

Mentions: Figure 1 shows effects of both continuous and reciprocal changes of nearly optimal (28/20 °C) and enhanced growth temperatures (36/28 °C) on six organic acids, including four TCA cycle intermediates, from soybean leaflets using plants grown with ambient CO2 (39 Pa) Citrate, malate and malonate were the most abundant organic acids in soybean leaf tissue (Figure 1A–C, respectively). Foliar citrate concentrations were 83% lower in the 36/28 versus the 28/20 °C growth temperature treatment, when all four harvest dates in the continuous growth temperature treatments were averaged (Table 1). Malate and succinate (Figure 1E) also were 50 and 45% less in soybean leaflets when plants were grown in the higher compared to lower temperature treatment. Unlike the other five organic acids shown here, glycerate levels were not temperature responsive (Figure 1D and Table 1). Malonate and fumarate (Figure 1F) were unique in that levels of these two organic acids in the either temperature treatment were similar on the first harvest date (day 0), although both of these compounds were more than 50% lower in the 36/28 compared to the 28/20 °C temperature treatments on the final sampling (day 3).


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 grown with ambient CO2 partial pressures. Plants were grown from seeds using continuous growth temperatures of 28/20 °C (●—●) or 36/28 °C (○—○). The first 21 or 22 DAS selected plants were transferred from the higher to lower (∆-----∆) or from the lower to higher (▼-----▼) growth treatment.
© Copyright Policy
Related In: Results  -  Collection

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

metabolites-05-00443-f001: Effects of reciprocal changes of growth temperature on concentrations of organic acids in soybean leaflets grown with ambient CO2 partial pressures. Plants were grown from seeds using continuous growth temperatures of 28/20 °C (●—●) or 36/28 °C (○—○). The first 21 or 22 DAS selected plants were transferred from the higher to lower (∆-----∆) or from the lower to higher (▼-----▼) growth treatment.
Mentions: Figure 1 shows effects of both continuous and reciprocal changes of nearly optimal (28/20 °C) and enhanced growth temperatures (36/28 °C) on six organic acids, including four TCA cycle intermediates, from soybean leaflets using plants grown with ambient CO2 (39 Pa) Citrate, malate and malonate were the most abundant organic acids in soybean leaf tissue (Figure 1A–C, respectively). Foliar citrate concentrations were 83% lower in the 36/28 versus the 28/20 °C growth temperature treatment, when all four harvest dates in the continuous growth temperature treatments were averaged (Table 1). Malate and succinate (Figure 1E) also were 50 and 45% less in soybean leaflets when plants were grown in the higher compared to lower temperature treatment. Unlike the other five organic acids shown here, glycerate levels were not temperature responsive (Figure 1D and Table 1). Malonate and fumarate (Figure 1F) were unique in that levels of these two organic acids in the either temperature treatment were similar on the first harvest date (day 0), although both of these compounds were more than 50% lower in the 36/28 compared to the 28/20 °C temperature treatments on the final sampling (day 3).

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