| Summary: | 碩士 === 國立臺灣大學 === 農藝學系 === 82 === The aim of this thesis was to study the effects of cadmium on
the growth of etiolated rice seedlings and on the changes of
ethylene production, NH4+, proline and polyamine levels in leaf
segments and roots of etiolated seedlings of rice. The possible
role of ethylene production, NH4+, proline and polyamine in the
growth inhibition induced by cadmium was investigated.The main
results are outlined as follows: 1.Cadmium inhibited the growth
of the root of rice seedlings. 2.Cadmium chloride was found to
be less effective than cadmium sulfate in inhibiting root
growth of rice seedlings. 3.Glutathione (reduced form), L-
glutamic acid and L-cysteine were able to recover the growth
inhibition of roots by cadmium chloride, whereas BSO, enhanced
the growth inhibition of roots induced by cadmium chloride.
4.Cadmium chloride treatment reduced ethylene production of
rice seedlings, increased proline level and ionically bound
peroxidase activity in the roots of rice seedlings. 5.Ethylene
production, proline level and ionically bound peroxid- ase
activity in detached leaves were found to be promoted by
cadmium chloride at low concentration under light condition.
6.Cadmium induced ethylene production was observed in detached
leaves of Indica type rice, but not in those of Japonica type
rice. 7.Cadmium inhibited ethylene production was reducted in
detached leaves from heat shock seedlings. 8. Pretreatment of
detached leaves with ABA, MJ and IAA prior cadmium stress
caused reduction in ethylene production. 9. At high
concentration, heavy metals were able to promote the
accumulation of proline in deatched rice leaves.
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