Abstract
Short-term experiments were conducted with vegetative soybean plants (Glycine max L. Merrill, cv. 'Ransom') to determine whether source-sink manipulations in the dark affected the apparent rate of starch mobilization and the activities of several enzymes involved in sucrose metabolism. When 'demand' for sucrose from a particular source leaf was increased in the dark by defoliation of all other source leaves, leaf sucrose-content was reduced initially, but the rate of starch mobilization was unaffected relative to intact controls. Defoliation altered the magnitude of the diurnal rhythm in sucrose phosphate synthase (SPS) activity such that the activity of SPS was markedly greater in defoliated plants relative to the controls. In contrast defoliation had no effect on the activities of sucrose synthase, cytosolic fructose bisphosphatase, and UDP-glucose pyrophosphorylase. The rate of sucrose formation in the dark was apparently limited by the rate of starch mobilization, and could not be increased by short-term changes in the demand for sucrose.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 247-252 |
| Number of pages | 6 |
| Journal | Plant Science Letters |
| Volume | 34 |
| Issue number | 3 |
| DOIs | |
| State | Published - 1984 |
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Keywords
- Assimilate demand in dark
- Diurnal rhythm
- Glycine max (L.) Merr
- Starch mobilization
- Sucrose phosphate synthase
Cite this
Effects of canopy defoliation in the dark on the activity of sucrose phosphate synthase. / Rufty, Thomas W.; Huber, Steven C; Kerr, Phillip S.
In: Plant Science Letters, Vol. 34, No. 3, 1984, p. 247-252.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of canopy defoliation in the dark on the activity of sucrose phosphate synthase
AU - Rufty, Thomas W.
AU - Huber, Steven C
AU - Kerr, Phillip S.
PY - 1984
Y1 - 1984
N2 - Short-term experiments were conducted with vegetative soybean plants (Glycine max L. Merrill, cv. 'Ransom') to determine whether source-sink manipulations in the dark affected the apparent rate of starch mobilization and the activities of several enzymes involved in sucrose metabolism. When 'demand' for sucrose from a particular source leaf was increased in the dark by defoliation of all other source leaves, leaf sucrose-content was reduced initially, but the rate of starch mobilization was unaffected relative to intact controls. Defoliation altered the magnitude of the diurnal rhythm in sucrose phosphate synthase (SPS) activity such that the activity of SPS was markedly greater in defoliated plants relative to the controls. In contrast defoliation had no effect on the activities of sucrose synthase, cytosolic fructose bisphosphatase, and UDP-glucose pyrophosphorylase. The rate of sucrose formation in the dark was apparently limited by the rate of starch mobilization, and could not be increased by short-term changes in the demand for sucrose.
AB - Short-term experiments were conducted with vegetative soybean plants (Glycine max L. Merrill, cv. 'Ransom') to determine whether source-sink manipulations in the dark affected the apparent rate of starch mobilization and the activities of several enzymes involved in sucrose metabolism. When 'demand' for sucrose from a particular source leaf was increased in the dark by defoliation of all other source leaves, leaf sucrose-content was reduced initially, but the rate of starch mobilization was unaffected relative to intact controls. Defoliation altered the magnitude of the diurnal rhythm in sucrose phosphate synthase (SPS) activity such that the activity of SPS was markedly greater in defoliated plants relative to the controls. In contrast defoliation had no effect on the activities of sucrose synthase, cytosolic fructose bisphosphatase, and UDP-glucose pyrophosphorylase. The rate of sucrose formation in the dark was apparently limited by the rate of starch mobilization, and could not be increased by short-term changes in the demand for sucrose.
KW - Assimilate demand in dark
KW - Diurnal rhythm
KW - Glycine max (L.) Merr
KW - Starch mobilization
KW - Sucrose phosphate synthase
UR - http://www.scopus.com/inward/record.url?scp=58149373165&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=58149373165&partnerID=8YFLogxK
U2 - 10.1016/S0304-4211(84)80003-6
DO - 10.1016/S0304-4211(84)80003-6
M3 - Article
AN - SCOPUS:58149373165
VL - 34
SP - 247
EP - 252
JO - Plant Science
JF - Plant Science
SN - 0168-9452
IS - 3
ER -