Table I.

Levels of metabolites in plant cytosol; PFP and H+-PPase activities from different plants and experimental conditions used in this study

Plants and Conditions Metabolites in Plant Cytosola Enzyme Activity Level
F1,6BP Pi Fru-6P PPi PFPb H+-PPasec
mm milliunits g fresh wt-1
Wild-type plants 0.6 5 1 0.33 293-1,813 15-25
Antisense transformant plants (lower levels) - - - - 20-58 -
Experimental conditions (Figs. 1, 2, and 4) - - - - 0.5-60d 18-25d
  • a The concentrations of F1,6BP, Pi, and F6P are those reported in the literature for plant cell cytosol (Rebeille et al., 1983; Ukaji and Ashihara, 1987; Weiner et al., 1987; Kubota and Ashihara, 1990; Davies et al., 1993; Stitt, 1998). b The PFP activities for wild-type and antisense transformant tobacco (Nicotiana tabacum) plants were taken from Nielsen and Stitt (2001) for antisense transformant potato (Solanum tuberosum) plants. Values are from Hajirezaei et al. (1994). c The H+-PPase activities for wild-type mung bean, tomato (Lycopersicon esculentum) fruit, and maize leaves were taken from Maeshima and Yoshida (1989), Milner et al. (1995), and Clayton et al. (1993), respectively. d The PFP and H+-PPase activities shown in this report were converted to milliunits per gram fresh wt-1 computing the enzyme activity level (milliunits) present in 1 mL of reaction medium. This volume was converted to grams to obtain the activities shown.