Abstract
Secondary wall formation requires coordinated transcriptional regulation of the genes involved in the biosynthesis of the components of secondary wall. Transcription factor (TF) MYB46 (At5g12870) has been shown to function as a central regulator for secondary wall formation in Arabidopsis thaliana, activating biosynthetic genes as well as the TFs involved in the pathways. Recently, we reported that MYB46 directly regulates secondary wall-associated cellulose synthase (CESA4, CESA7, and CESA8) and a mannan synthase (CSLA9) genes. However, it is not known whether MYB46 directly activates the biosynthetic genes for hemicellulose and lignin, which are the other two major components of secondary wall. Based on the observations that the promoter regions of many of the secondary wall biosynthetic genes contain MYB46-binding cis-regulatory motif(s), we hypothesized that MYB46 directly regulates the genes involved in the biosynthesis of the secondary wall components. In this report, we describe several lines of experimental evidence in support of the hypothesis. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis showed that MYB46 directly binds to the promoters of 13 genes involved in lignin and xylan biosynthesis. We then used steroid receptor-based inducible activation system to confirm that MYB46 directly activates the transcription of the xylan and lignin biosynthetic genes. Furthermore, ectopic up-regulation of MYB46 resulted in a significant increase in xylose and a small increase in lignin content based on acetyl bromide soluble lignin measurements in Arabidopsis. Taken together, we conclude that MYB46 function as a central and direct regulator of the genes involved in the biosynthesis of all three major secondary wall components.
Similar content being viewed by others
References
Albersheim P, Nevins DJ, English PD, Karr A (1967) A method for the analysis of sugars in plant cell wall polysaccharides by gas–liquid chromatography. Carbohydr Res 5:340–345
Aoyama T, Chua NH (1997) A glucocorticoid-mediated transcriptional induction system in transgenic plants. Plant J 11(3):605–612. doi:10.1046/j.1365-313X.1997.11030605.x
Baucher M, Halpin C, Petit-Conil M, Boerjan W (2003) Lignin: genetic engineering and impact on pulping. Crit Rev Biochem Mol Biol 38(4):305–350. doi:10.1080/10409230390242443
Boerjan WW, Ralph JJ, Baucher MM (2003) Lignin biosynthesis. Ann Rev Plant Biol 54:519–546. doi:10.1146/annurev.arplant.54.031902.134938
Brown DM, Zhang Z, Stephens E, Dupree P, Turner SR (2009) Characterization of IRX10 and IRX10-like reveals an essential role in glucuronoxylan biosynthesis in Arabidopsis. Plant J 57:732–746. doi:10.1111/j.1365-313X.2008.03729.x
Chang XF, Chandra R, Berleth T, Beatson RP (2008) Rapid, microscale, acetyl bromide-based method for high-throughput determination of lignin content in Arabidopsis thaliana. J Agric Food Chem 56:6825–6834. doi:10.1021/jf800775f
Demura T, Ye ZH (2010) Regulation of plant biomass production. Curr Opin Plant Biol 13:299–304. doi:10.1016/j.pbi.2010.03.002
Foster CE, Martin TM, Pauly M (2010a) Comprehensive compositional analysis of plant cell walls (Lignocellulosic biomass) part I: lignin. J Vis Exp 37. doi:10.3791/1745
Foster CE, Martin TM, Pauly M (2010b) Comprehensive compositional analysis of plant cell walls (Lignocellulosic biomass) part II: carbohydrares. J Vis Exp 37. doi:10.3791/1837
Goicoechea M, Lacombe E, Legay S, Mihaljevic S, Rech P, Jauneau A, Lapierre C, Pollet B, Verhaegen D, Chaubet-Gigot N, Grima-Pettenati J (2005) EgMYB2, a new transcriptional activator from eucalyptus xylem, regulates secondary cell wall formation and lignin biosynthesis. Plant J 43:553–567. doi:10.1111/j.1365-313X.2005.02480.x
Keppler B, Showalter AM (2010) IRX14 and IRX14-LIKE, two glycosyl transferases involved in glucuronoxylan biosynthesis and drought tolerance in Arabidopsis. Mol Plant 3:834–841. doi:10.1093/mp/ssq028
Kim WC, Ko JH, Han KH (2012) Identification of a cis-acting regulatory motif recognized by MYB46, a master transcriptional regulator of secondary wall biosynthesis. Plant Mol Biol 78:489–501. doi:10.1007/s11103-012-9880-7
Kim WC, Ko JH, Kim JY, Kim JM, Bae HJ, Han KH (2013a) MYB46 directly regulates the gene expression of secondary wall-associated cellulose synthases in Arabidopsis. Plant J 73:26–36. doi:10.1111/j.1365-313x.2012.05124.x
Kim WC, Kim JY, Ko JH, Kim JM, Han KH (2013b) Transcription factor MYB46 is an obligate component of the transcriptional regulatory complex for functional expression of secondary wall-associated cellulose synthases in Arabidopsis thaliana. J Plant Physiol. doi:10.1016/j.jplph.2013.04.012
Kim WC, Reca I-B, Kim YS, Park S, Thomashaw MF, Keegstra K, Han K-H (2014) Transcription factors that directly regulate the expression of CSLA9 encoding mannan synthase in Arabidopsis thaliana. Plant Mol Biol 84:577–587. doi:10.1007/s11103-013-0154-9
Ko JH, Beers EP, Han KH (2006) Global comparative transcriptome analysis identifies gene network regulating secondary xylem development in Arabidopsis thaliana. Mol Genet Genomics 276:517–531. doi:10.1007/s00438-006-0157-1
Ko JH, Yang SH, Park AH, Lerouxel O, Han KH (2007) ANAC012, a member of the plant-specific NAC transcription factor family, negatively regulates xylary fiber development in Arabidopsis thaliana. Plant J 50:1035–1048. doi:10.1111/j.1365-313X.2007.03109.x
Ko JH, Kim WC, Han KH (2009) Ectopic expression of MYB46 identifies transcriptional regulatory genes involved in secondary wall biosynthesis in Arabidopsis. Plant J 60(4):649–665. doi:10.1111/j.1365-313X.2009.03989.x
Ko J-H, Kim H-T, Han K-H (2011) Biotechnological improvement of lignocellulosic feedstock for enhanced biofuel productivity and processing. Plant Biotech Rep 1–7. doi:10.1007/s11816-010-0159-7
Ko JH, Kim WC, Kim JY, Ahn SJ, Han KH (2012) MYB46-mediated transcriptional regulation of secondary wall biosynthesis. Mol Plant 5(5):961–963. doi:10.1093/mp/sss076
Kubo M, Udagawa M, Nishikubo N, Horiguchi G, Yamaguchi M, Ito J, Mimura T, Fukuda H, Demura T (2005) Transcription switches for protoxylem and metaxylem vessel formation. Genes Dev 19:1855–1860. doi:10.1101/gad.1331305
Lee C, Teng Q, Zhong R, Ye ZH (2011) Molecular dissection of xylan biosynthesis during wood formation in poplar. Mol Plant 4:730–747. doi:10.1093/mp/ssr035
McCarthy RL, Zhong R, Ye ZH (2009) MYB83 is a direct target of SND1 and acts redundantly with MYB46 in the regulation of secondary cell wall biosynthesis in Arabidopsis. Plant Cell Physiol 50(11):1950–1964. doi:10.1093/pcp/pcp139
Mitsuda N, Seki M, Shinozaki K, Ohme-Takagi M (2005) The NAC transcription factors NST1 and NST2 of Arabidopsis regulates secondary wall thickening and are required for anther dehiscence. Plant Cell 17:2993–3006. doi:10.1105/tpc.105.036004
Mitsuda N, Iwase A, Yamamoto H, Yoshida M, Seki M, Shinozaki K, Ohme-Takagi M (2007) NAC transcription factors, NST1 and NST3, are key regulators of the formation of secondary walls in woody tissues of Arabidopsis. Plant Cell 19:270–280. doi:10.1105/tpc.106.047043
Novaes E, Kirst M, Chiang V, Winter-Sederoff H, Sederoff R (2010) Lignin and biomass: a negative correlation for wood formation and lignin content in trees. Plant Physiol 154:555–561. doi:10.1104/pp.110.161281
Ohman D, Demedts B, Kumar M, Gerber L, Gorzsás A, Goeminne G, Hedenström M, Ellis B, Boerjan W, Sundberg B (2012) MYB103 is required for FERULATE-5-HYDROXYLASE expression and syringyl lignin biosynthesis in Arabidopsis stems. Plant J 73:63–76. doi:10.1111/tpj.12018
Patzlaff A, McInnis S, Courtenay A, Surman C, Newman LJ, Smith C, Bevan MW, Mansfield S, Whetten RW, Sederoff RR, Campbell MM (2003a) Characterization of a pine MYB that regulates lignification. Plant J 36:743–754. doi:10.1046/j.1365-313X.2003.01916.x
Patzlaff A, Newman LJ, Dubos C, Whetten RW, Smith C, McInnis S, Bevan MW, Sederoff RR, Campbell MM (2003b) Characterization of PtMYB1, an R2R3-MYB from pine xylem. Plant Mol Biol 53:597–608. doi:10.1023/B:PLAN.0000019066.07933.d6
Pena MJ, Zhong R, Zhou G-K, Richardson EA, O’Neill MA, Darvill AG, York WS, Ye Z-H (2007) Arabidopsis irregular xylem8 and irregular xylem9: implications for the complexity of glucuronoxylan biosynthesis. Plant Cell 19:549–563. doi:10.1105/tpc.106.049320
Raes J, Rohde A, Christensen JH, Van de Peer Y, Boerjan W (2003) Genome-wide characterization of the lignification toolbox in Arabidopsis. Plant Physiol 133:1051–1071. doi:10.1104/pp.103.026484
Sheen J (2001) Signal transduction in maize and Arabidopsis mesophyll protoplasts. Plant Physiol 127(4):1466–1475. doi:10.1104/pp.010820
Steiner-Lange S, Unte US, Eckstein L, Yang C, Wilson ZA, Schmelzer E, Dekker K, Saedler H (2003) Disruption of Arabidopsis thaliana MYB26 results in male sterility due to non-dehiscent anthers. Plant J 34:519–528. doi:10.1046/j.1365-313X.2003.01745.x
Vanholme R, Cesarino I, Rataj K, Xiao Y, Sundin L, Goeminne G, Kim H, Cross J, Morreel K, Araujo P, Welsh L, Haustraete J, McClellan C, Vanholme B, Ralph J, Simpson GG, Halpin C, Boerjan W (2013) Caffeoyl shikimate esterase (CSE) is an enzyme in the lignin biosynthetic pathway in Arabidopsis. Science 341(6150):1103–1106. doi:10.1126/science.1241602
Wang HZ, Dixon RA (2012) On–off switches for secondary cell wall biosynthesis. Mol Plant 5:297–303. doi:10.1093/mp/ssr098
Wang Y, Chantreau M, Sibout R, Hawkins S (2013) Plant cell wall lignification and monolignol metabolism. Front Plant Sci 4:220. doi:10.3389/fpls.2013.00220
Yamaguchi M, Kubo M, Fukuda H, Demura T (2008) Vascular-related NAC-DOMAIN7 is involved in the differentiation of all types of xylem vessels in Arabidopsis roots and shoots. Plant J 55:652–664. doi:10.1111/j.1365-313X.2008.03533.x
Yang C, Xu Z, Song J, Conner K, Vizcay-Barrena G, Wilson ZA (2007) Arabidopsis MYB26/MALE STERILE35 regulates secondary thickening in the endothecium and is essential for anther dehiscence. Plant Cell 19:534–548. doi:10.1105/tpc.106.046391
Yoshida K, Sakamoto S, Kawai T, Kobayashi Y, Sato K, Ichinose Y, Yaoi K, Akiyoshi-Endo M, Sato H, Takamizo T, Ohme-Takaki M, Mitsuda N (2013) Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation. Front Plant Sci. doi:10.3389/fpls.2013.00383
Zhao Q, Dixon RA (2011) Transcriptional networks for lignin biosynthesis: more complex than we thought? Trends Plant Sci 16:227–233. doi:10.1016/j.tplants.2010.12.005
Zhao Q, Wang H, Yin Y, Xu Y, Chen F, Dixon RA (2010) Syringyl lignin biosynthesis is directly regulated by a secondary cell wall master switch. PNAS 107:14496–14501. doi:10.1073/pnas.1009170107
Zhong R, Ye ZH (2012) MYB46 and MYB83 bind to the SMRE sites and directly activate a suite of transcription factors and secondary wall biosynthetic genes. Plant Cell Physiol 53(2):368–380. doi:10.1093/pcp/pcr185
Zhong R, Pena MJ, Zhou GK, Nairn CJ, Wood-Jones A, Richardson EA, Morrison WH 3rd, Darvill AG, York WS, Ye ZH (2005) Arabidopsis fragile fiber8, which encodes a putative glucuronyltransferase, is essential for normal secondary wall synthesis. Plant Cell 17:3390–3408. doi:10.1105/tpc.105.035501
Zhong R, Demura T, Ye Z-H (2006) SND1, a NAC domain transcription factor, is a key regulator of secondary wall synthesis in fibers of Arabidopsis. Plant Cell 18:3158–3170. doi:10.1105/tpc.106.047399
Zhong R, Richardson EA, Ye ZH (2007) The MYB46 transcription factor is a direct target of SND1 and regulates secondary wall biosynthesis in Arabidopsis. Plant Cell 19(9):2776–2792. doi:10.1105/tpc.107.053678
Zhong R, Lee C, Zhou J, McCarthy RL, Ye ZH (2008) A battery of transcription factors involved in the regulation of secondary cell wall biosynthesis in Arabidopsis. Plant Cell 20:2763–2782. doi:10.1105/tpc.108.061325
Zhou J, Lee C, Zhong R, Ye ZH (2009) MYB58 and MYB63 are transcriptional activators of the lignin biosynthetic pathway during secondary cell wall formation in Arabidopsis. Plant Cell 21:248–266. doi:10.1105/tpc.108.063321
Zhu X, Pattathil S, Mazumder K, Brehm A, Hahn MG, Dinesh-Kumar SP, Joshi CP (2010) Virus-induced gene silencing offers a functional genomics platform for studying plant cell wall formation. Mol Plant 3:818–833. doi:10.1093/mp/ssq023
Acknowledgments
This work was funded by the DOE Great Lakes Bioenergy Research Center (DOE Office of Science BER DR-FC02-07ER64494), in part a Grant to J-H Ko by Basic Science Research Program through the National Research Foundation of Korea (NRF) (2011-0008840) and a Grant to J-H Ko from the Korea Forest Service (S111213L080110), and a Grant to HS Kang by Mid-Career Researcher Program through the National Research Foundation of Korea (2011-0017357).
Author information
Authors and Affiliations
Corresponding author
Additional information
Won-Chan Kim and Joo-Yeol Kim have contributed equally and are considered co-first authors.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Kim, WC., Kim, JY., Ko, JH. et al. Identification of direct targets of transcription factor MYB46 provides insights into the transcriptional regulation of secondary wall biosynthesis. Plant Mol Biol 85, 589–599 (2014). https://doi.org/10.1007/s11103-014-0205-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11103-014-0205-x