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TO T IPO T EN CY AND M O R PH O G E N E SIS O F PLANT C E L L S
IN V IT R O
HORMONALREGULATIONOFCOMPETENCEOFMAIZETISSUES FOR
SOMATICEMBRYOGENESIS
Yu.I.Dolgikh, T.N.Pustovoitova, N.E.Zhdanova, S.L.Belyanskava
К.A.Timiryazev Institute ofPlantPhysiologyRASMoscow, 127276, Botanicheskaya 35,
Maize genotypes are known to differ in their ability to morphogenesis
in
vitro.
The degree o f competence fo r morphogenesis can depend on
concentration o f endogenous phytohormones in cells o f explants. Using
immunoassay the content o f free auxin, cytokinins and abscisic acid were
compared in: 1) immature embryos isolated at the optimal for callus induction
stage o f development from kernels o f regenerable (A188) and recalcitrant
(Gk26) maize lines; 2) mature and immature embryos o fA188 which differ in
the morphogenic ability. The analysis revealed the connection between the
frequency o f embryogenic callus formation and the concentration o f hormones
in explan t ce lls. The competent fo r som atic embryogenesis tissues
characterized by relatively low level o f IAA and CK and high concentration of
ABA. Inhibitors o f auxin synthesis, cofactors o f IAA oxydase and exogenous
ABA were used to temporally change the content o f endogenous hormones
in the isolated embryos. The treatment o f Gk26 embryos w ith ABA resulted
in ten fold increase o f frequency o f explants form ing embryogenic ca lli.
The work is supportedbyRFFI (grant№96-04-51029).
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