ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Pyrophosphate: d-fructose-6-phosphate 1-phosphotransferase (PFP; EC 2.7.1.90) and ATP: d-fructose-6-phosphate 1-phosphotransferase (PFK; EC 2.7.1.11) activities were determined in sugarcane varieties differing in sucrose content. For this purpose, activities were measured in those internodes where the maximum rate of sucrose accumulation occurs. The specific activity of internodal PFP varied significantly between the sugarcane varieties and was inversely correlated with the sucrose content. There was also a highly significant inverse correlation between PFP and sucrose content in a segregating F1 population. PFK activity was comparable to, or lower than, PFP activity and no relationship was evident between PFK activity and sucrose content. In all tissues investigated, the fructose 2,6-bisphosphate levels were probably sufficient to ensure full activation of PFP. The levels of PFP activity appear to be controlled by the expression of the β-subunit of the protein. The molecular mass of the PFP subunit polypeptide(s) was approximately 63 kDa. There was an inverse correlation between sucrose content and the partitioning of radiolabel into respiration in internodal tissue slices labelled with [U-14C]glucose across 3 sugarcane lines. The estimated flux of carbon into respiration correlated directly with PFP activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1034/j.1399-3054.1999.100402.x
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