ISSN:
1432-2048
Keywords:
Acetolactate synthase
;
Amino acid (branched chain)
;
Arabidopsis
;
Feedback regulation
;
Mutant
;
Valine resistance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A valine-resistant mutant line, VAL-2, of Arabidopsis thaliana (L.) Heynh. was identified by screening M 2 populations of ethylmethane-sulfonate-mutagenized seeds. The resistance was found to be due to a single, dominant, nuclear gene mutation. Assay of acetolactate synthase (ALS) indicated that the valine resistance in this mutant is caused by decreased sensitivity of ALS to the branched-chain amino acids, valine, leucine and isoleucine. A two fold decrease in apparent K m value for pyruvate of the mutant ALS enzyme was detected compared with that of the wild type. The sensitivity of the ALS enzyme to sulfonylurea, imidazolinone and triazolopyrimidine herbicides was not altered in the mutant. At the plant growth level the mutant was also resistant to valine plus leucine, but was sensitive to leucine or isoleucine alone. The mutant gene, var1, maps, or is very closely linked, to CSR1, the gene encoding acetolactate synthase in Arabidopsis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00194459
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