Regulation of sucrose synthesis in water stressed leaves

Conference · Wed May 01 00:00:00 EDT 1991 · Plant Physiology, Supplement; (United States)

OSTI ID:5405589

Daie, J; Aloni, B ^[1]

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1. Rutgers, The State Univ. of New Jersey, New Brunswick (United States)

Alteration in carbon metabolism and carbohydrate partitioning occur in drought stressed plants. Some species accumulate large quantities of starch in the chloroplast, which may be used to support sucrose synthesis under conditions of limited carbon supply. The authors monitored chemical partitioning of carbon between sugars and starch and the activity of sucrose phosphate synthase (SPS) and fructose 1,6 bisphosphatase (FBPase) in the source leaves of water stressed tomatoes. Plants were stressed by withdrawing water for 10 days and rewatered for recovery. Water potential dropped from {minus}0.8 to {minus}2.2MPA in 10 days, but recovered to control level 2 days after rewatering. Photosynthetic rates as measured by the activity of Rubisco followed similar patterns to those of water potential. After 10 days, leaf starch levels decreased to less than 50% of control. Sucrose levels did not increase significantly, but hexose levels increased 3-4 fold during the stress period, and decreased to control levels 1 day after rewatering. FBPase activity decreased and SPS activity increased under stress conditions. Upon rewatering, the activity of FBPase and SPS returned to control levels. Presence of large quantities of hexose and activation of SPS in stressed leaves suggested that additional sucrose synthesized under stress was hydrolyzed to hexoses, presumably due to enhanced invertase activity.

• OSTI ID: 5405589
• Report Number(s): CONF-9107184-; CODEN: PPYSA
• Journal Information: Plant Physiology, Supplement; (United States), Vol. 96:1; Conference: Annual meeting of the American Society of Plant Physiology, Albuquerque, NM (United States), 28 Jul - 1 Aug 1991; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
DROUGHTS
ENVIRONMENTAL EFFECTS
LEAVES
BIOLOGICAL STRESS
METABOLISM
BIOLOGICAL EFFECTS
CARBOHYDRATES
CARBON
ENZYME ACTIVITY
PHOTOSYNTHESIS
RIBULOSE DIPHOSPHATE CARBOXYLASE
CARBON-CARBON LYASES
CARBOXY-LYASES
CHEMICAL REACTIONS
ELEMENTS
ENZYMES
LYASES
NONMETALS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PROTEINS
SYNTHESIS
540210* - Environment
Terrestrial- Basic Studies- (1990-)