title: Cloning and characterization of boron transporters in Brassica napus.
abstract: Six full-length cDNA encoding boron transporters (BOR) were isolated from Brassica napus (AACC) by rapid amplification of cDNA ends (RACE). The phylogenic analysis revealed that the six BORs were the orthologues of AtBOR1, which formed companying with the triplication and allotetra-ploidization process of B. napus, and were divided into three groups in B. napus. Each group was comprised of two members, one of which was originated from Brassica rapa (AA) and the other from Brassica oleracea (CC). Based on the phylogenetic relationships, the six genes were named as BnBOR1;1a, BnBOR1;1c, BnBOR1;2a, BnBOR1;2c, BnBOR1;3a and BnBOR1;3c, respectively. The deduced BnBOR1 s had extensive similarity with other plant BORs, with the identity of 74-96.8% in amino acid sequence. The BnBOR1;3a and BnBOR1;3c resembled AtBOR1 in number and positions of the 11 introns, but the others only have 9 introns. After the gene duplication, there was evidence of purifying selection under a divergent selective pressure. The expression patterns of the six BnBOR1 s were detected by semi-quantitative RT-PCR. The BnBOR1;3a and BnBOR1;3c showed a ubiquitous expression in all of the investigated tissues, whereas the other four genes showed similar tissue-specific expression profile. Unlike the non-transcriptional regulation of AtBOR1, the expression of BnBOR1;1c and BnBOR1;2a were obviously induced by boron deficiency. This study suggested that the BOR1 s had undergone a divergent expression pattern in the genome of B. napus after that the B. napus diverged from Arabidopsis thaliana.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zhang
authors.forename: Fangsen
authors.initials: F
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D017920:Antiporters / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D001896:Boron Compounds / Q000378:metabolism*; D029688:Brassica napus / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D040461:Gene Components; D020440:Gene Duplication; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013045:Species Specificity
chemical_list: D017920:Antiporters; D029681:Arabidopsis Proteins; C469216:BOR1 protein, Arabidopsis; D001896:Boron Compounds; D018076:DNA, Complementary