Abstract
We studied the genetic variation in barley grain lipoxygenase (LOX) activity, developed a simple assay to estimate the LOX activity, and identified a new LOX-deficient mutant line. Grain LOX activity differed considerably by as much as 2.2-fold among 72 Japanese cultivars. Most of the cultivars with a high LOX activity had been released in the past, such as “Tochigi golden melon”. We developed a simple assay to estimate the barley LOX activity by modifying the soybean LOX isozyme detection system. By using this assay, we identified a LOX-deficient mutant line “Daikei LM1” from the 258 M3 lines derived from the sodium azide-treated, 6-row malting cultivar “Karl.” DNA sequence analysis of the Lox-1 gene of “Daikei LM1” revealed a single nucleotide substitution (C to T) at nucleotide 2005, which introduced an internal stop codon into the third exon of Lox-1.
