Porphyrin metabolism in lead and mercury treated bajra (Pennisetum typhoideum) seedlings.
J Biosci
;
1990 Dec; 15(4): 271-279
Artigo
em Inglês
| IMSEAR
| ID: sea-160846
ABSTRACT
Lead and mercury inhibited porphyrin biosynthesis significantly in the germinating seeds of bajra (Pennisetum typhoideum). Both 5-aminolevulinic acid dehydratase and porphobilinogen deaminase activities were inhibited by these metals. A comparative study of the inhibition of these two enzymes under in vivo and in vitro conditions showed that 5-aminolevulinic acid dehydratase is the major site of action of heavy metals in porphyrin biosynthesis. Further, over-all production of porphyrins viz., protoporphyrin-IX, Mg-protoporphyrin (ester) and protochlorophyllide was repressed by lead and mercury in both light and dark grown seedlings. Similarly, chlorophyll a and chlorophyll b and total chlorophyll contents in dark-grown seedlings were also significantly decreased, suggesting the impairment of chlorophyll biosynthesis by lead and mercury in germinating seedlings.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Idioma:
Inglês
Revista:
J Biosci
Ano de publicação:
1990
Tipo de documento:
Artigo
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