Carbon allocation in developing spruce needles. Enzymes and intermediates of sucrose metabolism

Abstract

Effenberger. S. and Einig. W. 1994. Carbon allocation in developing spruce needles. Enzymes and intermediates of sucrose metabolism. -Physiol. Plant. 90: 299-306. In lyophilized needles of Norway spruce {Picea abies [L.] Karsten) and starting from bud break, we determined enzyme activities (sucrose phosphate synthase [SPS: EC 2.4.1.14). sucrose synthase [SS: EC 2.4.1.13]. acid invertase [AI: EC 3.2.1.26]) and intermediates (starch, sucrose, glucose, fructose: fructose 6-phosphate, fructose 2,6bisphosphate [F26BP1) of carbohydrate metabolism together with needle weight, shoot length, chlorophyll and protein.For up to 110 days after bud break, samples were taken twice a week from about 25-year-old trees under field conditions. At least three periods can be distinguished during needle maturation. During the first period (up to 45 days after bud break) Al showed the highest escractable activity. This coincided with terj high levels of F26BP (up to II pmoi [mg dry weight] ') and a transient increase of starch in parallel to a decrease of sucrose. The interval between 45 and 70 days after bud break was characterized by high SS activity (ratio of fructose/glucose >11, much decreased le\els of F26BP (down to below 1 pmol [mg dr> weight] '). and a pronounced increase in the dry w-eight/fresh weighl ratio. In parallel, starch declined and soluble carbohydrates increa.sed. Finally, needle maturation was characterized by decreasing SS and continuously increasing SPS acti\ities, so that the ratio of SPS/SS increased more than 6-fold. ,\l. however did not decline with maturation. Changes in poo) siz.es of metabolites and enzyme acti\'iiies (AI, SPSi are consisteni with current concepts on sink/.source transition. SS is obviously important with regard to the synthesis of structural polysaccharides.

The GAOLAOZHUANGREN1 Gene Encodes a Putative Glycosyltransferase that is Critical for Normal Development and Carbohydrate Metabolism

“…The resulting samples were incubated at room temperature for 25 min with occasional vortexes, followed by centrifugation at 10,000×g for 10 min. The supernatants were used for soluble sugar assays with an enzymic method (Hampp et al 1994). The absorbance was recorded by a microplate reader system (Sunrise, Phenix, Candler, NC, U.S.A.).…”

The effect of sulphite on chlorophyll fluorescence and sucrose metabolism in poplar leaves

“…A reciprocal dependence exists between Fru2,6BP and SuSy activity. In general, an increase in SuSy activity occurs if Fru2,6BP levels decrease (Hampp et al 1994). In the present study the reciprocal dependence between Fru2,6BP and SuSy seems to exist in leaves fed with < 5.0 mM of sulphite, where a decrease in the activity of SuSy coincided with an increase in Fru2,6BP content ( Figure B and F).…”

Activities of enzymes of starch metabolism in developing Norway spruce [Picea abies (L.) Karst.] needles

“…In a first attempt to characterize carbohydrate metabolism during the development of Norway spruce needles for up to 100 days after bud break (Hampp et al 1994), we distinguished three different metabolic stages which were characterized by (a) high levels of acid invertase activity, an increased pool size of fructose 2,6-bisphosphate (F26BP), and a transient increase of starch, all indicative of sucrose import and conversion into starch, (b) an intermediary stage, dominated by increased rates of sucrose synthase activity, decreased pool sizes of F26BP, as well as a pronounced increase in the ratio of dry weight/fresh weight and, finally (c) a sharp rise in the ratio of activities of sucrose phosphate synthase versus sucrose synthase, indicative for sink/source transition. In parallel, we detected considerable fluctuations in starch which was high shortly after bud break and declined to very low levels at the end of the experimental period.…”