Location: Sugarbeet and Potato Research
Title: Alterations in Respiration Rate and Glycolytic Intermediates in Wounded Sugarbeet Roots Authors
Submitted to: Plant Biology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 28, 2009
Publication Date: July 1, 2009
Citation: Lafta, A.M., Fugate, K.K. 2009. Alterations in Respiration Rate and Glycolytic Intermediates in Wounded Sugarbeet Roots [abstract]. American Society of Plant Biologists and Phycological Society of America. Paper No. P51009, p 346. Technical Abstract: Wounding of sugarbeet roots causes an increase in respiration rate, which contributes to postharvest sucrose losses. Although respiration is estimated to cause 60 to 80% of postharvest sucrose losses, the mechanisms that regulate respiration rate in wounded sugarbeet roots are not well know. To identify mechanisms of respiratory control for wounded sugarbeet roots, root respiration was characterized with respect to early glycolytic substrates and their related enzymes. Glycolytic substrates and enzymes were characterized in wounded roots at the site of injury and in unwounded tissue, allowing localized and systemic changes to be determined. Respiration increased in wounded roots after 3 days storage. Fructose increased in wounded tissue compared to unwounded control roots or the uninjuried tissue from wounded roots. There were also localized and systemic increases in glucose 6-P and fructose 6-P in wounded roots. Glucose 1-P increased in the unwounded tissue of wounded roots but was unchanged in wounded tissue. Triose phosphate and fructose 1,6-BP decreased in wounded tissue compared to unwounded control roots. This decrease could be due to their utilization as substrates in the elevated respiration rate of wounded tissue. Hexokinase and fructokinase activities increased in wounded tissue after 2 and 4 days. However, phosphofructokinase activity transiently increased in systemic tissue of wounded roots and transiently declined in wounded tissue. The increase in glucose 6-P and fructose 6-P corresponded with the activation of hexokinase and fructokinase in wounded tissue. Changes in glycolytic intermediates and enzymes in wounded tissue suggest that glycolysis is altered in response to wounding, possibly to provide additional substrates for elevated root respiration.