title: Molecular characterization of lipoxygenase genes on chromosome 4BS in Chinese bread wheat (Triticum aestivum L.).
abstract: This study cloned two novel TaLox genes on chromosome of 4BS and developed a co-dominant marker, Lox-B23, in bread wheat that showed highly significant association with lipoxygenase activity. Lipoxygenase (Lox), a critical enzyme in the carotenoid biosynthetic pathway, significantly influences the color and processing quality of wheat-based products. Two novel Lox genes, designated TaLox-B2 and TaLox-B3, were cloned on chromosome 4BS of Chinese bread wheat. The deduced amino acid sequence showed that both TaLox-B2 and TaLox-B3 genes encoded an 861-aa protein and possessed a lipoxygenase superfamily domain at the 170-838 interval. Two different TaLox-B2 alleles, designated TaLox-B2a and TaLox-B2b, were subsequently discovered. A co-dominant marker, Lox-B23, was developed based on sequences of TaLox-B2a, TaLox-B2b, and TaLox-B3 genes to precisely distinguish these three alleles in Chinese bread cultivars. Among five allelic combinations of Lox genes at Lox-B1, Lox-B2, and Lox-B3 loci, wheat cultivars with TaLox-B1a/TaLox-B2a/TaLox-B3a combination exhibited the highest Lox activity, whereas those with TaLox-B1a/TaLox-B2b/TaLox-B3b combination significantly showed the lowest Lox activity. A RIL population was used to evaluate the influence of TaLox-B3a gene on Lox activity. Results showed that TaLox-B3a gene could significantly increase the Lox activity in bread wheat. Physical mapping indicated that both TaLox-B2 and TaLox-B3 genes were located on chromosome 4BS in bread wheat. This study provides useful information to further understand the molecular and genetic bases of Lox activity in bread wheat.
authors.affiliation: Collaborative Innovation Center of Henan Grain Crops, Zhengzhou, 450002, China, zhangfuyan704@163.com.
authors.forename: Fuyan
authors.initials: F
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Peipei
authors.initials: P
authors.lastname: Wu
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Dangqun
authors.initials: D
authors.lastname: Cui
mesh_terms: D000483:Alleles; D001483:Base Sequence; D002874:Chromosome Mapping; D027042:Chromosomes, Artificial, P1 Bacteriophage; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D008040:Genetic Linkage; D005819:Genetic Markers; D008084:Lipoxygenase / Q000235:genetics*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000201:enzymology / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers; D010940:Plant Proteins; D008084:Lipoxygenase