ISSN:
1573-4927
Keywords:
phosphogluconate dehydrogenase
;
isozymes
;
maize
;
gene dosage
;
tissue-specific expression
;
null alleles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Maize (Zea mays L.) cytosolic 6-phosphogluconate dehydrogenase isozymes (EC 1.1.1.44; 6-PGD) are encoded by unlinked lociPgd1 andPgd2. Two families from a Robertson's Mutator line were isolated which have no detectable expression ofPgd2. ThesePgd2-null mutants and aPgd1-null line were used to generate plants homozygous for null alleles at both cytosolic 6-PGD loci. The specific activity of 6-PGD in the double-null mutant was between 20 and 30% of wild-type levels in root extracts. The double-null mutant was reproductively viable in a moderate environment, suggesting that wild-type levels of cytosolic 6-PGD activity are not essential for growth. Isozyme dimer ratios in roots, leaves, and scutellum were binomial and reflected the wild-type gene copy number. 6-PGD isozymes showed tissue- and cell type-specific expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02396214
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