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M ETABOLISM O F PLANT C E L L S IN CULTURE
AMYLOLYTICENZYMES IN CULTUREDCELLSOFCEREALSEEDS
A.A.Khakimzhanov, V.A.Kuzovlev, T.G.Krivtsun, R.K.Karakeeva, O.V.Fursov
M.A .Aytkhozhin Institute o fmolecularbiology and biochemistry, theRepublic o f
Kakhkstan, Almaty, 480012, Dosmukhamedov (Michurin) st., 86.
The
in vitro
cultures out of tissues of cereal seeds are very convenient
object fo r studies in the range of amylolytic enzymes regulation. The
hydrolases biosynthesis in sprouting kernel is known to be concentrated in
scutellum epithelium and aleuronic layer. The cell cultures o f isolated rice
scutellum o f the variety Marzhan (Oryza sativa L.) and maize (Zea mays)
Uzbek variety, obtained on MS nutrient medium (2 mg/l 2,4-D), were of high
a-amylase-producing capability. The ceils o f suspension culture actively
secreted enzyme (20-30% o fthe total protein amount) into cultured medium.
The physical and chemical properties o f the isolated enzyme have been
s tud ied . The e le c trop ho re tic com position o f aam y lase has been
heterogeneous and present in three groups o f components, as well as in
sprouting seeds. Isoenzymes with high and low pl had almost (42-44 kD)
and differed in their specificity to various cyclodextrins and affinity to Con-A-
sepharose. The revealed feature in the properties o f aamylase isoforms can
indicate at the presence of differences in their posttranslational modification
and secretion ways.
The research concerned the effect o f exogenous GA and ABA on the
growth o f callus mass and the level of a-amylase synthesis. A negative GA
effect on these parameters in the given auxin-dependent culture was shown.
On the contrary, ABA and 2,4-D in their mutual action caused a cooperative
effect, resulting in the increase of amylase activity.
O f some interest are studies on both metabolic regulation (changes in
the nutrient medium) for a-amylase induction to cultivated cells, and
regulation of activity by hormones, Ca2+ ions and external temperature.
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