Genetic study of glutamate oxaloacetic transaminase in soybean

A four-band electrophoretic zymogram for glutamate oxaloacetic transaminase (GOT, EC 2.6.1.1) is observed in mature soybean (Glycine max (L.) Merr.) seed. The zymogram pattern has a cluster of three bands (Rf's of 0.26, 0.29, and 0.32) and a single band. No variation was observed in the cluster of three bands. The fourth band has three variants that are controlled by a single locus, Got, with three alleles. They are designated as Got-a (Rf = 0.52), Got-b (Rf = 0.54), and Got-c (Rf = 0.57), respectively. In the wild soybean, G. soja (Sieb. & Zucc), the Got-a allele was found in four accessions from South Korea (PI 407.194, PI 407.269, PI 407.270, and PI 504.286; frequency 4/187). The Got-c allele also was found in four G. soja accessions from South Korea (PI 407.184, PI 407.207, PI 407.222, and PI 407.225; frequency 4/187). All other G. soja accessions examined carry the Got-b allele (frequency 179/187). All the G. max cultivars and accessions examined are homozygous for the Got-b allele (frequency 320/321) except for cv. Hardee, in which two seeds were homozygous for the Got-c allele. Linkage tests show that the Got locus segregates independently of the Ap, Dia1, Dia2, Idh1, Pgd2, and W1 loci. No linkage was detected when isozyme loci other than Got were tested (Am3–W1, Ap–W1, Dia1–W1, Pgd–W1, Dia1–Idh1, Pgd2–Idh1, and Ap–Idh2). Key words: soybean, glutamate oxaloacetic transaminase, GOT, electrophoresis, isozymes.