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Assimilate partitioning in Pachyrhizus erosus tubers under short days
Author(s) -
Vaillant Victor,
Desfontaines Lucienne
Publication year - 1995
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1995.tb06858.x
Subject(s) - sucrose , fructose , starch , chemistry , botany , carbohydrate , sugar , horticulture , food science , biology , biochemistry
The distribution of 14 C products in yam bean ( Pachyrhizus erosus ) plants was measured as a function of time after a 14 CO 2 pulse‐chase experiment under short‐day conditions. The 14 C declined by more than 70% in leaves during the first two hours, indicating that they actively exported carbon. Tubers were strong storage sinks for carbon and accumulated more than 80% of the total incorporated 14 C after a 72‐h chase. The data show that, although sucrose represented about 21% of the tuber non‐structural carbohydate, i.e. 15% of the tuber dry weight, 14 C did not accumulate in sucrose but in glucose, fructose and starch. The data indicate the existence of a separate sucrose pool which is affected only very slowly by recent assimilates. As a result, recent photosynthates, temporarily stored, may contribute to the reservoir of carbon available for nitrogen fixation. The data also suggest the existence of two distinct pools of amino acids in the tuber, one utilized mostly for protein synthesis and the other probably stored in the vacuole.