Respiratory acclimation in Arabidopsis thaliana leaves at low temperature.
Acclimation of 25 degrees C-grown Arabidopsis thaliana at 5 degrees C resulted in a marked increase of leaf respiration in darkness (Rd) measured at 5 degrees C. Rd was particularly high in leaves developed at 5 degrees C. Leaf respiration (non-photorespiratory intracellular decarboxylation) in the light (Rl) also increased during cold acclimation, but less so than did Rd. The ratio Rd/Pt (Pt - true photosynthesis) was higher in more acclimated or cold-developed leaves, while the ratio Rl/Pt remained unchanged. In cold-acclimated leaves, Rl did not correlate with 3-phosphoglycerate and pyruvate nor with hexose phosphate pools in the cytosol. Rl in A. thaliana leaves was probably not limited by the substrate during cold acclimation. Under the conditions tested, Rd was more sensitive to low temperature stress than Rl.
Talts
Peeter
P
Institute of Experimental Biology at the Estonian Agricultural University, Institud tee 11, 76902 Harku, Estonia. ptalts@solo.ee
Pärnik
Tiit
T
Gardeström
Per
P
Keerberg
Olav
O
D000064:Acclimatization; D017360:Arabidopsis / Q000502:physiology*; D003080:Cold Temperature; D003624:Darkness; D005988:Glyceric Acids / Q000032:analysis; D008027:Light; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis; D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D019289:Pyruvic Acid / Q000032:analysis; D013696:Temperature
D005988:Glyceric Acids; C005156:3-phosphoglycerate; D019289:Pyruvic Acid; C024254:hexose phosphatase; D010744:Phosphoric Monoester Hydrolases