Structural and expressional analysis of the B-hordein genes in Tibetan hull-less barley.
The B-hordein gene family was analyzed from two Tibetan hull-less barley cultivars Z09 and Z26 (Hordeum vulgare subsp. vulgare). Fourteen B-hordein genes, designated BZ09-2 to BZ09-5 (from Z09) and BZ26-1 to BZ26-10 (from Z26), were sequenced. Seven of them, similar to a previously reported BZ09-1 from Z09, were predicted to encode putative active proteins each with a signal peptide, a repetitive domain, and a C-terminal region; seven of them were predicted to be pseudogenes. The B-hordein gene family was analyzed using all known representatives of B-hordein sequences and two most similar LMW-GSs of Triticum aestivum. Alignment of these seven putative proteins with known B-hordeins and two most similar LMW-GSs of T. aestivum revealed that they shared a common motif. A large variation was observed between numbers of repeat units of predicted B-hordeins of Z26 and Z09. Phylogenetic analysis revealed that all BZ26 clones were clustered in a subgroup, and BZ09-1 formed another subgroup by itself in the putative eight active genes. In addition, six 5'-upstream regulatory sequences of the B-hordein genes were isolated from the two accessions by a single oligonucleotide nested PCR, and several different mutations were identified in the cis-acting element GLM and two distinctive sequences (Z09P-2 and Z26P-3). Phylogenetic analysis of 5'-upstream regulatory regions of the B-hordein genes showed that members from the same accession were clustered together except for two distinct members. Quantitative real time PCR analysis indicated distinct expression levels of B-hordein genes in four developing stages of developing grains in two accessions. These findings suggest B-hordein genes have intrinsic differences between accessions, and this knowledge will be useful for incorporating the B-hordeins protein in barley breeding programs.
College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
Zhaoxue
Z
Han
Fang
F
Wu
Guangbing
G
Deng
Gang
G
Qian
Maoqun
M
Yu
Yulin
Y
Jia
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D005983:Glutens / Q000737:chemistry* / Q000235:genetics*; D001467:Hordeum / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D012333:RNA, Messenger; D005983:Glutens