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Carbon allocation to the insoluble fraction, respiration and triose‐phosphate cycling in the sugarcane culm
Author(s) -
Bindon Keren A.,
Botha Frederick C.
Publication year - 2002
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 - 10.1034/j.1399-3054.2002.1160102.x
Subject(s) - plant stem , sucrose , respiration , carbon fibers , hexose , chemistry , phosphate , botany , biology , horticulture , biochemistry , enzyme , materials science , composite number , composite material
The changes in carbon allocation to non‐sucrose metabolic pathways were investigated in developing internodes of sugarcane. Radiolabelling studies were done on internode 3, 6 and 9 tissues, representing three stages of increasing maturity. Carbon partitioning into sucrose increased from 34% of total 14 C uptake in internode 3, to 66% in internodes 9. In immature tissue, the protein and fibre components were the dominant competing sinks with sucrose for incoming carbon, to which 14 and 16% of carbon was allocated. Increased carbon allocation to sucrose with tissue maturity coincided with a decrease in partitioning to fibre and total respiration. Between internodes 3 and 9 carbon allocation to total respiration decreased by 9%, and to fibre by 14%. Carbon cycling between the triose‐ and hexose phosphate pools was evident in all internodes. More than 90% of carbon entering triose‐phosphates was returned to hexose in internode 3 tissue, and this flux decreased with tissue maturity.