Forster C, North H, Afzal N, Domoney C, Hornostaj A, Robinson D S, Casey R
John Innes Centre, Norwich Research Park, UK.
Plant Mol Biol. 1999 Apr;39(6):1209-20. doi: 10.1023/a:1006173313548.
A mutant line of Pisum fulvum was identified that lacked seed lipoxygenase-2 (LOX-2). The mutant phenotype was introgressed into a standard Pisum sativum cv. Birte to provide near-isogenic lines with or without seed LOX-2. Genetic analyses showed the mutation to behave as a single, recessive Mendelian gene. Northern and dot-blot analyses showed a large reduction in LOX-2 mRNA from developing seeds of the LOX-2-null mutant. A restriction fragment length polymorphism associated with the 5' end of the LOX-2 gene(s) co-segregated with the null phenotype, indicating that the reduction of LOX-2 mRNA was neither a consequence of deletion of the LOX genes nor a consequence of the action of a genetically distant regulatory gene. Analysis of the 5'-flanking sequences of LOX-2 genes from Birte and the near-isogenic LOX-2-null mutant revealed a number of insertions, deletions and substitutions within the promoter from the LOX-2-null mutant that could be responsible for the null phenotype. Incubation of crude seed LOX preparations from Birte and the LOX-2-null mutant showed that the latter generated relatively less 13-hydroperoxides and also produced relatively more hydroxy- and ketoacid compounds that have implications for the fresh-frozen pea industry.
已鉴定出一种缺乏种子脂氧合酶-2（LOX-2）的野生型豌豆突变系。该突变表型被导入标准栽培种豌豆cv. Birte中，以提供有或无种子LOX-2的近等基因系。遗传分析表明该突变表现为单个隐性孟德尔基因。Northern杂交和斑点杂交分析显示，LOX-2基因缺失突变体发育种子中的LOX-2 mRNA大幅减少。与LOX-2基因5'端相关的限制性片段长度多态性与缺失表型共分离，表明LOX-2 mRNA的减少既不是LOX基因缺失的结果，也不是遗传距离较远的调控基因作用的结果。对Birte和近等基因LOX-2基因缺失突变体的LOX-2基因5'侧翼序列分析表明，LOX-2基因缺失突变体启动子内存在一些插入、缺失和替换，可能是导致缺失表型的原因。对Birte和LOX-2基因缺失突变体的粗种子LOX制剂进行孵育表明，后者产生的13-氢过氧化物相对较少，还产生了相对较多的对鲜冻豌豆产业有影响的羟基和酮酸化合物。
