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Sucrose Metabolism Related to Growth and Ripening in Sugarcane Internodes
Author(s) -
Lingle Sarah E.,
Smith Robert C.
Publication year - 1991
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1991.0011183x003100010039x
Subject(s) - sucrose , plant stem , invertase , biology , fructose , sugar , saccharum , ripening , biochemistry , botany
Sucrose concentration is an important component of yield in sugarcane ( Saccharum spp. hybrids). To further understand the relationship of sucrose biochemistry to growth and sucrose accumulation in sugarcane, sugars, sucrose synthase (SS), acid and neutral invertases, pyrophosphate:fructose 6‐phosphate 1‐phosphotransferase (PPi‐PFP), fructose 2,6‐bisphosphate (F26BP), and adenosine triphosphate: fructose 6‐phosphate, 1‐kinase (ATP‐PFK) were extracted from the top eight internodes of greenhouse‐grown ‘CP 70‐321’ sugarcane plants. Internode 1 was defined as that subtended by the topmost leaf with exposed dewlap. Internodes 2 and 3 had the highest elongation rates; Internodes 5 to 8 were fully elongated. The rate of sugar accumulation, especially sucrose, increased rapidly after elongation ceased. The activity of SS was associated with elongation and may be related to sink strength of elongating internodes. Acid and neutral invertase activities were more generally distributed. When unstimulated by F26BP, the activity of PPi‐PFP was similar to that of ATP‐PKF. Addition of 1 µ M F26BP stimulated PPi‐PFP activity up to 60‐fold. The concentration of F26BP extracted from all internodes was sufficient to fully stimulate PPi‐PFP. There was no clear relationship between developmental stage, F26BP concentration, and the activity of PPi‐PFP or ATP‐PFK. Further investigations on the role of SS in sugarcane development seem warranted.