Regulatory Mechanism of Mediator Subunit MED25 on Multi-phytohormone Signaling Pathways

doi:10.13560/j.cnki.biotech.bull.1985.2018-0487

Abstract

Abstract: The multi-subunit mediators regulate gene expression by bridging RNA polymerase II and kinds of transcription factors into Pre-Initiation Complex to trigger specific transcriptional program. Mediator25（MED25）is one subunit of the plant mediator complex,implicated in regulating plant development and stress tolerance. MED25 participated in response of biotic and abiotic stresses by interacting with transcription activators（e.g.,MYCs,AP2/ERFs and ARFs）,repressors（e.g.,JAZs and Aux/IAAs）and other mediator subunits（e.g.,MED13 and MED16）,and regulation of phytohormone（JA,ABA,ethylene and IAA）signaling pathways. The target separation and functional identification of MED25 have been a hot topic in recent years. In this paper,the essential roles of MED25 in various hormone signaling pathways were reviewed and provide novel insights into how the plants pass hormone-specific regulatory signals and transcriptionally control physiological processes.

Key words: mediator complex, MED25, jasmonic acid, abscisic acid, auxin, ethylene

DOU Yue, LIU Mei-tong, LU An-na, WU Jia-jie, WANG Qun-qing, XU Qian. Regulatory Mechanism of Mediator Subunit MED25 on Multi-phytohormone Signaling Pathways[J]. Biotechnology Bulletin, 2018, 34(7): 40-47.

References

[1] Flanagan PM, Rd KR, Sayre MH, et al.A mediator required for activation of RNA polymerase II transcription in vitro[J]. Nature, 1991, 350(6317):436-438.
[2] Mathur S, Vyas S, Kapoor S, et al.The mediator complex in plants:structure, phylogeny, and expression profiling of representative genes in a dicot(Arabidopsis)and a Monocot(Rice)during reproduction and abiotic stress[J]. Plant Physiology, 2011, 157(4):1609-27.
[3] Allen BL, Taatjes DJ.The mediator complex:a central integrator of transcription[J]. Nature Reviews Molecular Cell Biology, 2015, 16(3):155-166.
[4] Samanta S, Thakur JK.Importance of mediator complex in the regulation and integration of diverse signaling pathways in plants[J]. Front Plant Sci, 2015, 6(7):388-394.
[5] Poss Z C, Ebmeier CC, Taatjes DJ.The mediator complex and transcription regulation[J]. Critical Reviews in Biochemistry & Molecular Biology, 2013, 48(6):575-608.
[6] Bäckström S, Elfving N, Nilsson R, et al.Purification of a plant mediator from Arabidopsis thaliana identifies PFT1 as the Med25 subunit[J]. Molecular Cell, 2007, 26(5):717.
[7] Cerdán PD, Chory J.Regulation of flowering time by light quality
[J]. Nature, 2003, 423(6942):881.
[8] Autran D, Jonak C, Belcram K, et al.Cell numbers and leaf development in Arabidopsis:a functional analysis of the STRUWWELPETER gene[J]. Embo Journal, 2002, 21(22):6036.
[9] Wang W, Chen X.HUA ENHANCER3 reveals a role for a cyclin-dependent protein kinase in thespecification of floral organ identity in Arabidopsis[J]. Development, 2004, 131(13):3147.
[10] Zheng W, Zhai Q, Sun J, et al.Bestatin, an inhibitor of aminopeptidases, provides a chemical genetics approach to dissect jasmonate signaling in Arabidopsis[J]. Plant Physiology, 2006, 141(4):1400-1413.
[11] Seguelaarnaud M, Smith C, Uribe MC, et al.The Mediator complex subunits MED25/PFT1 and MED8 are required for transcriptional responses to changes in cell wall arabinose composition and glucose treatment in Arabidopsis thaliana[J]. BMC Plant Biology, 2015, 15(1):1-13.
[12] Elfving N, Davoine C, Benlloch R, et al.The Arabidopsis thaliana Med25 mediator subunit integrates environmental cues to control plant development[J]. Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(20):8245.
[13] Kidd BN, Edgar CI, Kumar KK, et al.The mediator complex subunit PFT1 is a key regulator of jasmonate-dependent defense in Arabidopsis.[J]. Plant Cell, 2009, 21(8):2237-2252.
[14] Xu, Li.Control of final organ size by Mediator complex subunit 25 in Arabidopsis thaliana[J]. Development, 2011, 138(20):4545-4554.
[15] Xu R, Li Y.The Mediator complex subunit 8 regulates organ size in Arabidopsis thaliana[J]. Plant Signaling & Behavior, 2012, 7(2):182-183.
[16] Kazan K.The Multitalented MEDIATOR25[J]. Front Plant Sci, 2017, 8.
[17] Kidd B N, Cahill D M, Manners J M, et al.Diverse roles of the Mediator complex in plants.[J]. Seminars in Cell & Developmental Biology, 2011, 22(7):741-748.
[18] Larsson M, Uvell H, Sandström J, et al.Functional studies of the yeast med5, med15 and med16 mediator tail subunits.[J]. PLoS One, 2013, 8(8):e73137.
[19] Çevik V, Kidd B N, Zhang P, et al.MEDIATOR25 acts as an integrative hub for the regulation of jasmonate-responsive gene expression in Arabidopsis[J]. Plant Physiology, 2012, 160(1):541-555.
[20] Fernández-Calvo P, Solano R.The Arabidopsis bHLH transcription factors MYC3 and MYC4 are targets of JAZ repressors and act additively with MYC2 in the activation of jasmonate responses[J]. Plant Cell, 2011, 23(2):701-15.
[21] Zhang F, Yao J, Ke J, et al.Structural basis of JAZ repression of MYC transcription factors in jasmonate signalling[J]. Nature, 2015, 525(7568):269-73.
[22] Rival P, Press M O, Bale J, et al.The conserved PFT1 tandem repeat is crucial for proper flowering in Arabidopsis thaliana[J]. Genetics, 2014, 198(2):747-754.
[23] Yang Y, Li L, Qu L J.Plant Mediator complex and its critical functions in transcription regulation[J]. Journal of Integrative Plant Biology, 2016, 58(2):106-118.
[24] Dolan W L, Chapple C. Conservation and divergence of mediator structure and function:insights from plants[J]. Plant & Cell Physiology, 2016, 58(1):pcw176.
[25] Kazan, Kemal.Diverse roles of jasmonates and ethylene in abiotic stress tolerance[J]. Trends in Plant Science, 2015, 20(4):219-229.
[26] Kemal Kazan, John M.Manners. MYC2:the master in action[J]. Molecular Plant, 2013, 6(3):686-703.
[27] Kazan, Kemal, John M. JAZ repressors and the orchestration of phytohormone crosstalk[J]. Trends in Plant Science, 2012, 17(1):22-31.
[28] Boter M, Ruízrivero O, Abdeen A, et al.Conserved MYC transcription factors play a key role in jasmonate signaling both in tomato and Arabidopsis[J]. Genes Dev, 2004, 18(13):1577-1591.
[29] Lorenzo O, Chico JM, Sánchez-Serrano JJ, et al.JASMONATE-INSENSITIVE1 encodes a MYC transcription factor essential to discriminate between different jasmonate-regulated defense responses in Arabidopsis[J]. Plant Cell, 2004, 16(7):1938.
[30] Dombrecht B, Xue GP, Sprague SJ, et al.MYC2 differentially modulates diverse jasmonate-dependent functions in Arabidopsis[J]. Plant Cell, 2007, 19(7):2225-2245.
[31] Chen R, Jiang H, Li L, et al.The Arabidopsis mediator subunit MED25 differentially regulates jasmonate and abscisic acid signaling through interacting with the MYC2 and ABI5 transcription factors[J]. Plant Cell, 2012, 24(7):2898.
[32] Ou, Bin, Yin, et al. A high-throughput screening system for Arabidopsis transcription factors and its application to Med25-dependent transcriptional regulation[J]. Molecular Plant, 2011, 4(3):546-555.
[33] Riechmann JL, Heard J, Martin G, et al.Arabidopsis transcription factors:genome-wide comparative analysis among eukaryotes[J]. Science, 2000, 290(5499):2105.
[34] Gong W, Shen YP, Ma LG, et al.Genome-wide ORFeome cloning and analysis of Arabidopsis transcription factor genes[J]. Plant Physiology, 2004, 135(2):773-82.
[35] Nakano T, Suzuki K, Fujimura T, et al.Genome-wide analysis of the ERF gene family in Arabidopsis and rice[J]. Plant Physiology, 2006, 140(2):411.
[36] Kidd BN, Aitken EA, Schenk PM, et al.Plant mediator:mediating the jasmonate response[J]. Plant Signal Behav, 2010, 5(5):718-720.
[37] Zhang F, Ke J, Zhang L, et al.Structural insights into alternative splicing-mediated desensitization of jasmonate signaling[J]. Proceedings of the National Academy of Sciences of the United States of America, 2017, 114(7):1720.
[38] Zhu Y, Mengiste T.CYCLIN-DEPENDENT KINASE8 differentially regulates plant immunity to fungal pathogens through kinase-dependent and -independent functions in Arabidopsis[J]. Plant Cell, 2014, 26(10):4149-4170.
[39] Sela D, Buxdorf K, Shi J X, et al.Overexpression of AtSHN1/WIN1 provokes unique defense responses[J]. PLoS One, 2013, 8(7):e70146.
[40] 黄维娜, 康玉凡. 乙烯在幼苗根生长发育中调控作用的研究进展[J]. 中国农学通报, 2013(12):6-12.
[41] Rayagonzález J, Ortizcastro R, Ruízherrera L F, et al.PHYTOCHROME AND FLOWERING TIME1/MEDIATOR25 regulates lateral root formation via auxin signaling in Arabidopsis[J]. Plant Physiology, 2014, 165(2):880.
[42] Casimiro I, Beeckman T, Graham N, et al.Dissecting Arabidopsis, lateral root development[J]. Trends in Plant Science, 2003, 8(4):165-71.
[43] Hirota A, Kato T, Fukaki H, et al.The auxin-regulated AP2/EREBP Gene PUCHI is required for morphogenesis in the early lateral root primordium of Arabidopsis[J]. Plant Cell, 2007, 19(7):2156.
[44] Casimiro I, Marchant A, Bhalerao RP, et al.Auxin transport promotes Arabidopsis lateral root initiation.[J]. Plant Cell, 2001, 13(4):843.
[45] Himanen K, Boucheron E, Vanneste S, et al.Auxin-mediated cell cycle activation during early lateral root initiation[J]. Plant Cell, 2002, 14(10):2339-2351.
[46] Ito J, Fukaki H, Onoda M, et al.Auxin-dependent compositional change in mediator in ARF7- and ARF19-mediated transcription.[J]. Proceedings of the National Academy of Sciences of the United States of America, 2016, 113(23):6562.
[47] Muto H, Watahiki MK, Nakamoto D, et al.Specificity and similarity of functions of the Aux/IAA genes in auxin signaling of Arabidopsis revealed by promoter-exchange experiments among MSG2/IAA19, AXR2/IAA7, and SLR/IAA14[J]. Plant Physiology, 2007, 144(1):187-96.
[48] Bourras S, Mcnally KE, Ben-David R, et al.Multiple avirulence loci and allele-specific effector recognition control the Pm3 race-specific resistance of wheat to powdery mildew[J]. Plant Cell, 2015, 27(10):2991.
[49] Parlange F, Roffler S, Menardo F, et al.Genetic and molecular characterization of a locus involved in avirulence of Blumeria graminis, f. sp. tritici, on wheat Pm3, resistance alleles[J]. Fungal Genetics & Biology, 2015, 82:181-192.
[50] Duan X, Wang X, Fu Y, et al.TaEIL1, a wheat homologue of AtEIN3, acts as a negative regulator in the wheat-stripe rust fungus interaction[J]. Molecular Plant Pathology, 2013, 14(7):728.
[51] Liu J, Zhang T, Jia J, et al.The wheat mediator subunit TaMED25 interacts with the transcription factor TaEIL1 to negatively regulate disease resistance against powdery mildew[J]. Plant Physiology, 2016, 170(3):1799.
[52] Kazan K, Manners JM.Linking development to defense:auxin in plant-pathogen interactions[J]. Trends in Plant Science, 2009, 14(7):373-382.
[53] Carlos L, Romera FJ, García MJ, et al.Ethylene participates in the regulation of Fe deficiency responses in strategy I plants and in rice[J]. Front Plant Sci, 2015, 6(155):1056.
[54] Brumbarova, Tzvetina, Bauer, et al. Molecular mechanisms governing Arabidopsis iron uptake[J]. Trends in Plant Science, 2015, 20(2):124-133.
[55] Yang Y, Ou B, Zhang J, et al.The Arabidopsis Mediator subunit MED16 regulates iron homeostasis by associating with EIN3/EIL1 through subunit MED25[J]. Plant Journal, 2014, 77(6):838-51.
[56] Zhang Y, Wu H, Wang N, et al.Mediator subunit 16 functions in the regulation of iron uptake gene expression in Arabidopsis[J]. New Phytologist, 2014, 203(3):770-83.
[57] Bu QY, Li HM, Zhao QZ, et al.The Arabidopsis RING finger E3 ligase RHA2a is a novel positive regulator of abscisic acid signaling during seed germination and early seedling development[J]. Plant Physiology, 2009, 150(1):463-481.
[58] Li H, Jiang H, Bu Q, et al.The Arabidopsis RING finger E3 ligase RHA2b acts additively with RHA2a in regulating abscisic acid signaling and drought response[J]. Plant Physiology, 2011, 156(2):550-563.
[59] Lopez-Molina L, Mongrand S, Chua NH.A postgermination developmental arrest checkpoint is mediated by abscisic acid and requires the ABI5 transcription factor in Arabidopsis[J]. Proceedings of the National Academy of Sciences of the United States of America, 2001, 98(8):4782-4787.
[60] Lopezmolina L, Mongrand S, Mclachlin DT, et al.ABI5 acts downstream of ABI3 to execute an ABA-dependent growth arrest during germination[J]. Plant Journal, 2002, 32(3):317-328.
[61] Li J, Zhang K, Meng Y, et al.Jasmonic acid/Ethylene signaling coordinates hydroxycinnamic acid amides biosynthesis through ORA59 transcription factor[J]. Plant Journal for Cell & Molecular Biology, 2018, 95(3):444-457.
[62] Campos L, Lisón P, López-Gresa MP, et al.Transgenic tomato plants overexpressing tyramine N-hydroxycinnamoyltransferase exhibit elevated hydroxycinnamic acid amide levels and enhanced resistance to Pseudomonas syringae[J]. Mol Plant Microbe Interact, 2014, 27(10):1159-1169.
[63] Atsushi M, Kenji M, Takeshi S, et al.Acquired immunity of transgenic torenia plants overexpressing agmatine coumaroyltransferase to pathogens and herbivore pests[J]. Scientific Reports, 2012, 2(689):689.
[64] Canet J V, Dobã³N A, Tornero P. Non-recognition-of-BTH4, an Arabidopsis mediator subunit homolog, is necessary for development and response to salicylic acid[J]. Plant Cell, 2012, 24(10):4220-4235.
[65] Zhang X, Wang C, Zhang Y, et al.The Arabidopsis mediator complex subunit16 positively regulates salicylate-mediated systemic acquired resistance and jasmonate/ethylene-induced defense pathways[J]. Plant Cell, 2012, 24(10):4294.
[66] Caillaud M, Asai S, Rallapalli G, et al.A downy mildew effector attenuates salicylic acid-triggered immunity in arabidopsis by interacting with the host mediator complex[J]. PLoS Biology, 2013, 11(12):e1001732.
[67] Wang Y, Hu Z, Zhang J, et al.Silencing SlMED18, tomato mediator subunit 18 gene, restricts internode elongation and leaf expansion[J]. Scientific Reports, 2018, 8(1):3285.