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Dark chilling imposes metabolic restrictions on photosynthesis in soybean
Author(s) -
VAN HEERDEN P. D. R.,
KRÜGER G. H. J.,
LOVELAND J. E.,
PARRY M. A. J.,
FOYER C. H.
Publication year - 2003
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.2003.00966.x
Subject(s) - rubisco , photosynthesis , phosphoenolpyruvate carboxylase , sucrose , sucrose phosphate synthase , chloroplast stroma , chloroplast , pyruvate carboxylase , chemistry , biochemistry , biology , botany , sucrose synthase , enzyme , thylakoid , gene , invertase
ABSTRACT Dark chilling inhibited photosynthesis in two soybean [ Glycine max (L.) Merr.] cultivars (Fiskeby V and Maple Arrow). The inhibition of CO 2 assimilation was characterized by a simultaneous decrease in stomatal conductance ( G s ) and intercellular CO 2 concentration ( C i ) in Maple Arrow, whereas a similar decrease in G s in Fiskeby V occurred without any change in C i . Dark chilling had little effect on total ribulose‐1, 5‐bisphosphate carboxylase/oxygenase (Rubisco) activity, Rubisco protein content or Rubisco activation state in the subsequent light period. Chilling reduced the abundance of the nocturnal Rubisco inhibitor, 2‐carboxyarabinitol 1‐phosphate, only in Fiskeby V. The abundance of Rubisco small subunit transcripts was enhanced in both cultivars as a result of dark chilling. Dark chilling decreased the maximal extractable activities and activation states of stromal fructose‐1,6‐bisphosphatase (FBPase) and NADP‐malate dehydrogenase but had no effect on sucrose phosphate synthase or leaf sucrose and starch contents. It is concluded that dark chilling‐induced limitations on CO 2 assimilation are predominantly due to metabolic restrictions rather than to direct effects on electron transport reactions and that stromal FBPase is particularly susceptible to dark chilling.