Abstract
Common wheat (2n = 6x = 42, genome formula AABBDD) accumulates benzoxazinones (Bxs) as defensive compounds. There are five Bx biosynthetic genes (TaBx1–TaBx5), and their homoeologous alleles are located on all three homoeologous chromosomes of the A, B and D genomes. Here the molecular structures of the TaBx3 and TaBx4 loci, both of which are located on chromosomes 5A, 5B and 5D, were revealed by sequencing transformation-competent artificial chromosome (TAC) clones. In all homoeologous chromosomes, TaBx3 existed downstream of TaBx4 in a tail-to-head manner, and the two genes were separated from each other by 9.0 kb in 5A, 7.3 kb in 5B and 11.3 kb in 5D. Among the three homoeologs of TaBx3 and TaBx4, the promoter sequences were less conserved than the coding sequences. The promoter sequences of TaBx3 and TaBx4 were highly similar to those of their respective orthologs in the diploid progenitors of common wheat, but were not similar to those of the maize orthologs. Sequence similarity was found between the TaBx3 and TaBx4 coding sequences, but not between their promoter sequences despite their similar transcription pattern at the seedling stage. Some putative cis-elements were found to be shared by all TaBx3 and TaBx4 promoter regions. These results imply that stage-specific transcription of TaBx3 and TaBx4 is not controlled by global sequence similarity of their promoters but by some essential cis-elements. The promoter activity measured by transient assays in wheat protoplasts was similar among the three homoeologs of TaBx3 and TaBx4 in spite of their differential transcript levels in wheat seedlings.
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References
An CI, Sawada A, Fukusaki E, Kobayashi A (2003) A transient RNA interference assay using Arabidopsis protoplasts. Biosci Biotechnol Biochem 67:2674–2677
Bottley A, Xia GM, Koebner RMD (2006) Homoeologous gene silencing in hexaploid wheat. Plant J 47:897–906
Chiu W, Niwa Y, Zeng W, Hirano T, Kobayashi H, Sheen J (1996) Engineered GFP as a vital reporter in plants. Curr Biol 6:325–330
Dubouzet JG, Morishige T, Fujii N, An CI, Fukusaki E, Ifuku K, Sato F (2005) Transient RNA silencing of scoulerine 9-O-methyltansferase expression by double stranded RNA in Coptis japonica protoplasts. Biosci Biotechnol Biochem 69:63–70
Ebisui K, Ishihara A, Hirai N, Iwamura H (1998) Occurrence of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and a β-glucosidase specific for its glucoside in maize seedlings. Z Naturforsch 53c:793–798
Feldman M, Levy AA (2005) Allopolyploidy - a shaping force in the evolution of wheat genomes. Cytogenet Genome Res 109:250–258
Frey M, Kliem R, Saedler H, Gierl A (1995) Expression of a cytochrome P450 gene family in maize. Mol Gen Genet 246:100–109
Frey M, Chomet P, Glawischnig E, Stettner C, Grün S, Winklmair A, Eisenreich W, Bacher A, Meeley RB, Briggs SP, Simcox K, Gierl A (1997) Analysis of a chemical plant defense mechanism in grasses. Science 277:696–699
Frey M, Stettner C, Paré PW, Schmelz EA, Tumlinson JH, Gierl A (2000) An herbivore elicitor activates the gene for indole emission in maize. Proc Natl Acad Sci USA 97:14801–14806
Gachon CMM, Langlois-Meurinne M, Henry Y, Saindrenan P (2005) Transcriptional co-regulation of secondary metabolism enzymes in Arabidopsis: functional and evolutionary implications. Plant Mol Biol 58:229–245
Gantet P, Memelink J (2002) Transcription factors: tools to engineer the production of pharmacologically active plant metabolites. Trends Pharmacol Sci 23:563–569
Grace ML, Chandrasekharan MB, Hall TC, Crowe AJ (2004) Sequence and spacing of TATA box elements are critical for accurate initiation from the β-phaseolin promoter. J Biol Chem 279:8102–8110
Grün S, Frey M, Gierl A (2005) Evolution of the indole alkaloid biosynthesis in the genus Hordeum: Distribution of gramine and DIBOA and isolation of the benzoxazinoids biosynthesis genes from Hordeum lechleri. Phytochemistry 66:1264–1272
Huang S, Sirikhachornkit A, Faris JD, Su X, Gill BS, Haselkorn R, Gornicki P (2002a) Phylogenetic analysis of the acetyl-CoA carboxylase and 3-phosphoglycerate kinase loci in wheat and other grasses. Plant Mol Biol 48:805–820
Huang S, Sirikhachornkit A, Su X, Faris J, Gill B, Haselkorn R, Gornicki P (2002b) Genes encoding plastid acetyl-CoA carboxylase and 3-phosphoglycerate kinase of the Triticum/Aegilops complex and the evolutionary history of polyploid wheat. Proc Natl Acad Sci USA 99:8133–8138
Jin H, Martin C (1999) Miltifunctionality and diversity within the plant MYB-gene family. Plant Mol Biol 41:577–585
Kato N, Dubouzet E, Kokabu Y, Yoshida S, Taniguchi Y, Dubouzet JG, Yazaki K, Sato F (2007) Identification of a WRKY protein as a transcriptional regulator of benzylisoquinoline alkaloid biosynthesis in Coptis japonica. Plant Cell Physiol 48:8–18
Lescot M, Déhais P, Thijs G, Marchal K, Moreau Y, Van de Peer Y, Rouzé P, Rombauts S (2002) PlantCARE, a database of plant cis-acting regulatory elements and a portal to tools for in silico analysis of promoter sequences. Nucl Acids Res 30:325–327
Liu Y-G, Nagaki K, Fujita M, Kawaura K, Uozumi M, Ogihara Y (2000) Development of an efficient maintenance and screening system for large-inserted genomic DNA libraries of hexaploid wheat in a transformation-competent artificial chromosome (TAC) vector. Plant J 23:687–695
Melanson D, Chilton M-D, Masters-Moore D, Chilton WS (1997) A deletion in an indole synthase gene is responsible for the DIMBOA-deficient phenotype of bxbx maize. Proc Natl Acad Sci USA 94:13345–13350
Menkens AE, Schindler U, Cashmore AR (1995) The G-box: a ubiquitous regulatory DNA element in plants bound by the GBF family of bZIP proteins. Trends Biochem Sci 20:506–510
Nakagawa E, Amano T, Hirai N, Iwamura H (1995) Non-induced cyclic hydroxamic acids in wheat during juvenile stage of growth. Phytochemistry 38:1349–1354
Niemeyer HM (1988) Hydroxamic acids (4-hydroxy-1,4-benzoxazin-3-ones): defence chemicals in the Gramineae. Phytochemistry 27:3349–3358
Nomura T, Ishihara A, Imaishi H, Endo TR, Ohkawa H, Iwamura H (2002) Molecular characterization and chromosomal localization of cytochrome P450 genes involved in the biosynthesis of cyclic hydroxamic acids in hexaploid wheat. Mol Genet Genomics 267:210–217
Nomura T, Ishihara A, Imaishi H, Ohkawa H, Endo TR, Iwamura H (2003) Rearrangement of the genes for the biosynthesis of benzoxazinones in the evolution of Triticeae species. Planta 217:776–782
Nomura T, Ishihara A, Yanagita RC, Endo TR, Iwamura H (2005) Three genomes differentially contribute to the biosynthesis of benzoxazinones in hexaploid wheat. Proc Natl Acad Sci USA 102:16490–16495
Nomura T, Ishihara A, Iwamura H, Endo TR (2007) Molecular characterization of benzoxazinone-deficient mutation in diploid wheat. Phytochemistry 68:1008–1016
Orozco BM, Ogren WL (1993) Localization of light-inducible and tissue-specific regions of the spinach ribulose bisphosphate carboxylase/oxygenase (rubisco) activase promoter in transgenic tobacco plants. Plant Mol Biol 23:1129–38
Ren X-Y, Fiers MWEJ, Stiekema WJ, Nap J-P (2005) Local coexpression domains of two to four genes in the genome of Arabidopsis. Plant Physiol 138:923–934
Rombauts S, Florquin K, Lescot M, Marchal K, Rouzé P, Van de Peer Y (2003) Computational approaches to identify promoters and cis-regulatory elements in plant genomes. Plant Physiol 132:1162–1176
Sarhan F, Cesar D (1988) High yield isolation of mesophyll protoplasts from wheat, barley and rye. Physiol Plant 72:337–342
Shitsukawa N, Tahira C, Kassai K, Hirabayashi C, Shimizu T, Takumi S, Mochida K, Kawaura K, Ogihara Y, Murai K (2007) Genetic and epigenetic alteration among three homoeologous genes of a class E MADS box gene in hexaploid wheat. Plant Cell 19: 1723–1737
Sicker D, Frey M, Schulz M, Gierl A (2000) Role of natural benzoxazinones in the survival strategy of plants. Int Rev Cytol 198:319–346
Sue M, Ishihara A, Iwamura H (2000) Purification and characterization of a β-glucosidase from rye (Secale cereale L.) seedlings. Plant Sci 155:67–74
Urao T, Yamaguchi-Shinozaki K, Urao S, Shinozaki K (1993) An Arabidopsis myb homolog is induced by dehydration stress and its gene product binds to the conserved MYB recognition site. Plant Cell 5:1529–1539
Vom Endt D, Kijne JW, Memelink J (2002) Transcription factors controlling plant secondary metabolism: what regulates the regulators? Phytochemistry 61:107–114
Wray GA, Hahn MW, Abouheif E, Balhoff JP, Pizer M, Rockman MV, Romano LA (2003) The evolution of transcriptional regulation in eukaryotes. Mol Biol Evol 20:1377–1419
Zhan S, Horrocks J, Lukens LN (2006) Islands of co-expressed neighbouring genes in Arabidopsis thaliana suggest higher-order chromosome domains. Plant J 45:347–357
Acknowledgments
We thank Dr. Ei-ichiro Fukusaki (Osaka University, Japan) for providing pPluc and phRluc vectors. We also acknowledge Dr. Yasuo Niwa (University of Shizuoka, Japan) for a gift of CaMV35S-sGFP (S65T)-NOS plasmid. This work was supported by a Grant-in-Aid for Scientific Research (No. 16000377) from the Japan Society for the Promotion of Science (to T.N.). Contribution No. 594 from the Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University, Japan.
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Communicated by E. Guiderdoni.
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Supplemental Table 4 Putative cis-regulatory elements in the promoter sequences shared by all TaBx3, but not all TaBx4, homoeologs and orthologs in common wheat and its diploid progenitors. (+) and (−) indicate strands on which each element is present (doc 95 KB)
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Nomura, T., Nasuda, S., Kawaura, K. et al. Structures of the three homoeologous loci of wheat benzoxazinone biosynthetic genes TaBx3 and TaBx4 and characterization of their promoter sequences. Theor Appl Genet 116, 373–381 (2008). https://doi.org/10.1007/s00122-007-0675-1
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DOI: https://doi.org/10.1007/s00122-007-0675-1