Akms. Alam et al., Changes in sucrose synthase and sucrose phosphate synthase activities, andsugar distribution in autumn-harvested asparagus, ACTA HORT, (506), 1999, pp. 109-114
Changes in sucrose synthase (SS), sucrose phosphate synthase (SPS) activiti
es and distribution of sugar content were investigated in asparagus (Aspara
gus officinalis L. cv. E414 and Green Tower) spears subjected to selected f
ertilizer treatments applied in the early-harvest (September) and harvestin
g (October) season. The results suggest that fertilizer application in the
early-harvest and harvesting season had no impact on the enzyme activities,
sugar distribution and spear weight. In the top portion of the spears in b
oth cultivars, SS activity gradually decreased with time with a concomitant
increase in the accumulation of sucrose producing a significant negative c
orrelation. This indicated that in the vigorously growing tissues, as in th
e top portion of the asparagus spears, SS is responsible for sucrose breakd
own. In the bottom portion of the two cultivars, however, SS remained const
ant. SPS activity remained constant in both portions of the two cultivars.
SS and SPS showed higher activities in the bottom than in the top portion o
f the spear but sucrose content increased gradually with time in both porti
ons of the two cultivars, and fructose concentrations were always higher th
an glucose.