Inhibition of chlorophyll biosynthesis by mercury in excised etiolated maize leaf segments during greening: effect of 2-oxoglutarate.
Indian J Exp Biol
;
2004 Apr; 42(4): 419-23
Article
in English
| IMSEAR
| ID: sea-56760
ABSTRACT
Mercury (0.01-1.0 mM) inhibited chlorophyll formation in greening maize leaf segments. However, supplementing incubation medium with 2-oxoglutarate, maintained substantially higher level of chlorophyll in absence of metal after an initial period of 8 hr. On preincubation of leaf segments with HgCl2, per cent inhibition of chlorophyll synthesis by metal was same in the presence and absence of 2-oxoglutarate. Supply of 2-oxoglutarate (0.1-10.0 mM) exerted concentration dependent effect on chlorophyll formation in absence or presence of metal. Increase in delta-amino levulinic acid dehydratase as well as NADH-glutamate synthase activity and decrease in NADH-glutamate dehydrogenase activity by 2-oxoglutarate in the presence of Hg suggested that glutamate for delta-amino levulinic acid synthesis could be made available from NH4+ assimilation via., glutamine synthetase/glutamate synthase pathway during mercury toxicity.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Photosynthesis
/
Radiation-Protective Agents
/
Chlorophyll
/
Plant Leaves
/
Glutamic Acid
/
Zea mays
/
Dose-Response Relationship, Drug
/
Glutamate Synthase
/
Aminolevulinic Acid
/
Porphobilinogen Synthase
Language:
English
Journal:
Indian J Exp Biol
Year:
2004
Type:
Article
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