The volatile two-carbon hormone ethylene acts in concert with an array of signals to affect etiolated seedling development. From a chemical screen, we isolated a quinoline carboxamide designated ACCERBATIN (AEX) that exacerbates the 1-aminocyclopropane-1-carboxylic acid-induced triple response, typical for ethylene-treated seedlings in darkness. Phenotypic analyses revealed distinct AEX effects including inhibition of root hair development and shortening of the root meristem. Mutant analysis and reporter studies further suggested that AEX most probably acts in parallel to ethylene signaling. We demonstrated that AEX functions at the intersection of auxin metabolism and reactive oxygen species (ROS) homeostasis. AEX inhibited auxin efflux in BY-2 cells and promoted indole-3-acetic acid (IAA) oxidation in the shoot apical meristem and cotyledons of etiolated seedlings. Gene expression studies and superoxide/hydrogen peroxide staining further revealed that the disrupted auxin homeostasis was accompanied by oxidative stress. Interestingly, in light conditions, AEX exhibited properties reminiscent of the quinoline carboxylate-type auxin-like herbicides. We propose that AEX interferes with auxin transport from its major biosynthesis sites, either as a direct consequence of poor basipetal transport from the shoot meristematic region, or indirectly, through excessive IAA oxidation and ROS accumulation. Further investigation of AEX can provide new insights into the mechanisms connecting auxin and ROS homeostasis in plant development and provide useful tools to study auxin-type herbicides.

Centre for Environmental Sciences Hasselt University Agoralaan Building D 3590 Diepenbeek Belgium

Department of Botany and Plant Sciences Institute of Integrative Genome Biology University of California Riverside CA 92521 USA

Department of Plant Systems Biology VIB Technologiepark 927 B 9052 Ghent Belgium

Institute of Experimental Botany ASCR 16500 Praha 6 Czech Republic

Laboratory of Functional Plant Biology Department of Biology Faculty of Sciences Ghent University K L Ledeganckstraat 35 B 9000 Ghent Belgium

NMR and Structure Analysis Department of Organic Chemistry Krijgslaan 281 S4 B 9000 Ghent Belgium

Zobrazit více v PubMed

Abel S, Theologis A. 1996. Early genes and auxin action. Plant Physiology 111, 9–17. PubMed PMC

Abeles FB, Morgan PW, Saltveit ME. 1992. Ethylene in plant biology. San Diego: Academic Press.

Alonso JM, Stepanova AN, Leisse TJ et al. 2003. Genome-wide insertional mutagenesis of PubMed

An F, Zhang X, Zhu Z, Ji Y, He W, Jiang Z, Li M, Guo H. 2012. Coordinated regulation of apical hook development by gibberellins and ethylene in etiolated PubMed PMC

Beemster GT, Baskin TI. 1998. Analysis of cell division and elongation underlying the developmental acceleration of root growth in PubMed PMC

Benjamini Y, Drai D, Elmer G, Kafkafi N, Golani I. 2001. Controlling the false discovery rate in behavior genetics research. Behavioural Brain Research 125, 279–284. PubMed

Blakeslee JJ, Bandyopadhyay A, Lee OR et al. 2007. Interactions among PIN-FORMED and P-glycoprotein auxin transporters in PubMed PMC

Bleecker AB, Estelle MA, Somerville C, Kende H. 1988. Insensitivity to ethylene conferred by a dominant mutation in PubMed

Blilou I, Xu J, Wildwater M et al. 2005. The PIN auxin efflux facilitator network controls growth and patterning in PubMed

Blomster T, Salojarvi J, Sipari N, Brosche M, Ahlfors R, Keinanen M, Overmyer K, Kangasjarvi J. 2011. Apoplastic reactive oxygen species transiently decrease auxin signaling and cause stress-induced morphogenic response in Arabidopsis. Plant Physiology 157, 1866–1883. PubMed PMC

Böger P, Matthes B, Schmalfuß J. 2000. Towards the primary target of chloroacetamides – new findings pave the way. Pest Management Science 56, 497–508.

Büntemeyer K, Lüthen H, Böttger M. 1998. Auxin-induced changes in cell wall extensibility of maize roots. Planta 204, 515–519.

Burg SP, Burg EA. 1966. The interaction between auxin and ethylene and its role in plant growth. Proceedings of the National Academy of Sciences, USA 55, 262–269. PubMed PMC

Calderón Villalobos LI, Lee S, De Oliveira C et al. 2012. A combinatorial TIR1/AFB-Aux/IAA co-receptor system for differential sensing of auxin. Nature Chemical Biology 8, 477–485. PubMed PMC

Chae HS, Faure F, Kieber JJ. 2003. The PubMed PMC

Collett CE, Harberd NP, Leyser O. 2000. Hormonal interactions in the control of Arabidopsis hypocotyl elongation. Plant Physiology 124, 553–562. PubMed PMC

Cosgrove DJ. 2005. Growth of the plant cell wall. Nature Reviews. Molecular Cell Biology 6, 850–861. PubMed

Cutler SR, Ehrhardt DW, Griffitts JS, Somerville CR. 2000. Random GFP∷cDNA fusions enable visualization of subcellular structures in cells of PubMed PMC

Davletova S, Schlauch K, Coutlu J, Mittler R. 2005. The Zinc-finger protein Zat12 plays a central role in reactive oxygen and abiotic stress signaling in Arabidopsis. Plant Physiology 139, 847–856. PubMed PMC

Delbarre A, Muller P, Imhoff V, Guern J. 1996. Comparison of mechanisms controlling uptake and accumulation of 2,4-dichlorophenoxy acetic acid, naphthalene-1-acetic acid, and indole-3-acetic acid in suspension-cultured tobacco cells. Planta 198, 532–541. PubMed

De Rybel B, Audenaert D, Vert G et al. 2009. Chemical inhibition of a subset of PubMed PMC

De Vylder J, Vandenbussche F, Hu Y, Philips D, Van Der Straeten D. 2012. Rosette tracker: an open source image analysis tool for automatic quantification of genotype effects. Plant Physiology 160, 1149–1159. PubMed PMC

Dharmasiri N, Dharmasiri S, Estelle M. 2005. The F-box protein TIR1 is an auxin receptor. Nature 435, 441–445. PubMed

Dobrev PI, Vankova R. 2012. Quantification of abscisic acid, cytokinin, and auxin content in salt-stressed plant tissues. Methods in Molecular Biology 913, 251–261. PubMed

Doerner P, Jorgensen JE, You R, Steppuhn J, Lamb C. 1996. Control of root growth and development by cyclin expression. Nature 380, 520–523. PubMed

Dong CH, Jang M, Scharein B, Malach A, Rivarola M, Liesch J, Groth G, Hwang I, Chang C. 2010. Molecular association of the PubMed PMC

Ellison CT, Vandenbussche F, Van Der Straeten D, Harmer SL. 2011. PubMed PMC

Gadjev I, Vanderauwera S, Gechev TS et al. 2006. Transcriptomic footprints disclose specificity of reactive oxygen species signaling in Arabidopsis. Plant Physiology 141, 436–445. PubMed PMC

Gälweiler L, Guan C, Müller A, Wisman E, Mendgen K, Yephremov A, Palme K. 1998. Regulation of polar auxin transport by AtPIN1 in PubMed

Gendron JM, Haque A, Gendron N, Chang T, Asami T, Wang ZY. 2008. Chemical genetic dissection of brassinosteroid-ethylene interaction. Molecular Plant 1, 368–379. PubMed PMC

Grossmann K. 2003. Mediation of herbicide effects by hormone interactions. Journal of Plant Growth Regulation 22, 109–122.

Grossmann K. 2010. Auxin herbicides: current status of mechanism and mode of action. Pest Management Science 66, 113–120. PubMed

Grossmann K, Kwiatkowski J. 1995. Evidence for a causative role of cyanide, derived from ethylene biosynthesis, in the herbicidal mode of action of quinclorac in barnyard grass. Pesticide Biochemistry and Physiology 51, 150–160.

Grossmann K, Kwiatkowski J, Tresch S. 2001. Auxin herbicides induce H PubMed

Grossmann K, Scheltrup F. 1998. Studies on the mechanism of selectivity of the auxin herbicide quinmerac. Pesticide Science 52, 111–118.

Hagen G, Guilfoyle T. 2002. Auxin-responsive gene expression: genes, promoters and regulatory factors. Plant Molecular Biology 49, 373–385. PubMed

Harper RM, Stowe-Evans EL, Luesse DR, Muto H, Tatematsu K, Watahiki MK, Yamamoto K, Liscum E. 2000. The PubMed PMC

Hayashi K, Tan X, Zheng N, Hatate T, Kimura Y, Kepinski S, Nozaki H. 2008. Small-molecule agonists and antagonists of F-box protein-substrate interactions in auxin perception and signaling. Proceedings of the National Academy of Sciences, USA 105, 5632–5637. PubMed PMC

He J, Duan Y, Hua D, Fan G, Wang L, Liu Y, Chen Z, Han L, Qu LJ, Gong Z. 2012. DEXH box RNA helicase-mediated mitochondrial reactive oxygen species production in PubMed PMC

He WR, Brumos J, Li HJ et al. 2011. A small-molecule screen identifies L-kynurenine as a competitive inhibitor of TAA1/TAR activity in ethylene-directed auxin biosynthesis and root growth in PubMed PMC

Hoagland RE, Boyette CD, Vaughn KC. 2011. Interactions of quinclorac with a bioherbicidal strain of

Hošek P, Kubeš M, Laňková M et al. 2012. Auxin transport at cellular level: new insights supported by mathematical modelling. Journal of Experimental Botany 63, 3815–3827. PubMed PMC

Hu Y, Callebert P, Vandemoortel I, Nguyen L, Audenaert D, Verschraegen L, Vandenbussche F, Van Der Straeten D. 2014. TR-DB: an open-access database of compounds affecting the ethylene-induced triple response in PubMed

Isaacs JT, Pili R, Qian DZ, Dalrymple SL, Garrison JB, Kyprianou N, Bjork A, Olsson A, Leanderson T. 2006. Identification of ABR-215050 as lead second generation quinoline-3-carboxamide anti-angiogenic agent for the treatment of prostate cancer. Prostate 66, 1768–1778. PubMed

Ivanchenko MG, den Os D, Monshausen GB, Dubrovsky JG, Bednarova A, Krishnan N. 2013. Auxin increases the hydrogen peroxide (H PubMed PMC

Irizarry RA, Hobbs B, Collin F, Beazer-Barclay YD, Antonellis KJ, Scherf U, Speed TP. 2003. Exploration, normalization, and summaries of high density oligonucleotide array probe level data. Biostatistics 4, 249–264. PubMed

Ju C, Yoon GM, Shemansky JM et al. 2012. CTR1 phosphorylates the central regulator EIN2 to control ethylene hormone signaling from the ER membrane to the nucleus in PubMed PMC

Kai K, Horita J, Wakasa K, Miyagawa H. 2007. Three oxidative metabolites of indole-3-acetic acid from PubMed

Knight L, Rose R, Crocker W. 1910. Effect of various gases and vapors upon etiolated seedlings of the sweet pea. Science 31, 635–636.

Kowalczyk M, Sandberg G. 2001. Quantitative analysis of indole-3-acetic acid metabolites in Arabidopsis. Plant Physiology 127, 1845–1853. PubMed PMC

Le J, Vandenbussche F, Van Der Straeten D, Verbelen JP. 2001. In the early response of Arabidopsis roots to ethylene, cell elongation is up- and down-regulated and uncoupled from differentiation. Plant Physiology 125, 519–522. PubMed PMC

Lee S, Sundaram S, Armitage L, Evans JP, Hawkes T, Kepinski S, Ferro N, Napier RM. 2014. Defining binding efficiency and specificity of auxins for SCF PubMed PMC

Lehman A, Black R, Ecker JR. 1996. PubMed

Li H, Johnson P, Stepanova A, Alonso JM, Ecker JR. 2004. Convergence of signaling of differential cell growth pathways in the control in PubMed

Lin LC, Hsu JH, Wang LC. 2010. Identification of novel inhibitors of 1-aminocyclopropane-1-carboxylic acid synthase by chemical screening in PubMed PMC

Ljung K, Hull AK, Celenza J, Yamada M, Estelle M, Normanly J, Sandberg G. 2005. Sites and regulation of auxin biosynthesis in Arabidopsis roots. The Plant Cell 17, 1090–1104. PubMed PMC

Lohse M, Nunes-Nesi A, Kruger P et al. 2010. Robin: an intuitive wizard application for R-based expression microarray quality assessment and analysis. Plant Physiology 153, 642–651. PubMed PMC

Lovelace ML, Talbert RE, Hoagland RE, Scherder EF. 2007. Quinclorac absorption and translocation characteristics in quinclorac- and propanil-resistant and -susceptible barnyardgrass

Lutman PJW, Sweet J, Berry K, Law J, Payne R, Simpson E, Walker K, Wightman P. 2008. Weed control in conventional and herbicide tolerant winter oilseed rape (

Maere S, Heymans K, Kuiper M. 2005. BiNGO: a Cytoscape plugin to assess overrepresentation of gene ontology categories in biological networks. Bioinformatics 21, 3448–3449. PubMed

Masucci JD, Schiefelbein JW. 1994. The PubMed PMC

Morreel K, Saeys Y, Dima O, Lu F, Van de Peer Y, Vanholme R, Ralph J, Vanholme B, Boerjan W. 2014. Systematic structural characterization of metabolites in Arabidopsis via candidate substrate-product pair networks. The Plant Cell 26, 929–945. PubMed PMC

Mravec J, Kubes M, Bielach A et al. 2008. Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development. Development 135, 3345–3354. PubMed

Muday GK, Brady SR, Argueso C, Deruere J, Kieber JJ, DeLong A. 2006. RCN1-regulated phosphatase activity and EIN2 modulate hypocotyl gravitropism by a mechanism that does not require ethylene signaling. Plant Physiology 141, 1617–1629. PubMed PMC

Muday GK, Rahman A, Binder BM. 2012. Auxin and ethylene: collaborators or competitors?Trends in Plant Science 17, 181–195. PubMed

Nagashima A, Uehara Y, Sakai T. 2008. The ABC subfamily B auxin transporter AtABCB19 is involved in the inhibitory effects of N-1-naphthyphthalamic acid on the phototropic and gravitropic responses of PubMed

Nagata T, Nemoto Y, Hasezawa S. 1992. Tobacco BY-2 cell-line as the “HeLa” cell in the cell biology of higher plants. International Review of Cytology 132, 1–30.

Nakamoto D, Ikeura A, Asami T, Yamamoto KT. 2006. Inhibition of brassinosteroid biosynthesis by either a PubMed PMC

Narayan Acharya B, Thavaselvam D, Parshad Kaushik M. 2008. Synthesis and antimalarial evaluation of novel pyridine quinoline hybrids. Medicinal Chemistry Research 17, 487–494.

Neljubov D. 1901. Uber die horizontale Nutation der Stengel von

Nemhauser JL, Hong F, Chory J. 2006. Different plant hormones regulate similar processes through largely nonoverlapping transcriptional responses. Cell 126, 467–475. PubMed

Noh B, Murphy AS, Spalding EP. 2001. PubMed PMC

Okushima Y, Mitina I, Quach HL, Theologis A. 2005. a. AUXIN RESPONSE FACTOR 2 (ARF2): a pleiotropic developmental regulator. The Plant Journal 43, 29–46. PubMed

Okushima Y, Overvoorde PJ, Arima K et al. 2005. b. Functional genomic analysis of the PubMed PMC

Olmedo G, Guo H, Gregory BD, Nourizadeh SD, Aguilar-Henonin L, Li H, An F, Guzman P, Ecker JR. 2006. PubMed PMC

Ostin A, Kowalyczk M, Bhalerao RP, Sandberg G. 1998. Metabolism of indole-3-acetic acid in Arabidopsis. Plant Physiology 118, 285–296. PubMed PMC

Park SY, Fung P, Nishimura N et al. 2009. Abscisic acid inhibits type 2C protein phosphatases via the PYR/PYL family of START proteins. Science 324, 1068–1071. PubMed PMC

Passardi F, Penel C, Dunand C. 2004. Performing the paradoxical: how plant peroxidases modify the cell wall. Trends in Plant Science 9, 534–540. PubMed

Pasternak T, Potters G, Caubergs R, Jansen MA. 2005. a. Complementary interactions between oxidative stress and auxins control plant growth responses at plant, organ, and cellular level. Journal of Experimental Botany 56, 1991–2001. PubMed

Pasternak T, Rudas V, Potters G, Jansen M. 2005. b. Morphogenic effects of abiotic stress: reorientation of growth in seedlings. Environmental and Experimental Botany 53, 299–314.

Peer WA, Cheng Y, Murphy AS. 2013. Evidence of oxidative attenuation of auxin signalling. Journal of Experimental Botany 64, 2629–2639. PubMed

Pencik A, Simonovik B, Petersson SV et al. 2013. Regulation of auxin homeostasis and gradients in PubMed PMC

Petrášek J, Cerna A, Schwarzerova K, Elckner M, Morris DA, Zazimalova E. 2003. Do phytotropins inhibit auxin efflux by impairing vesicle traffic?Plant Physiology 131, 254–263. PubMed PMC

Petrášek J, Zažímalová E. 2006. The BY-2 cell line as a tool to study auxin transport. In: Nagata T, Matsuoka K, Inzé D, eds. Tobacco BY-2 cells: from cellular dynamics to omics. Berlin, Heidelberg: Springer, 107–117.

Pitts RJ, Cernac A, Estelle M. 1998. Auxin and ethylene promote root hair elongation in PubMed

Prigge MJ, Greenham K, Zhang YI et al. 2016. The PubMed PMC

Rahman A, Hosokawa S, Oono Y, Amakawa T, Goto N, Tsurumi S. 2002. Auxin and ethylene response interactions during Arabidopsis root hair development dissected by auxin influx modulators. Plant Physiology 130, 1908–1917. PubMed PMC

Rakusova H, Gallego-Bartolome J, Vanstraelen M, Robert HS, Alabadi D, Blazquez MA, Benkova E, Friml J. 2011. Polarization of PIN3-dependent auxin transport for hypocotyl gravitropic response in PubMed

Raynes K, Foley M, Tilley L, Deady LW. 1996. Novel bisquinoline antimalarials: synthesis, antimalarial activity, and inhibition of haem polymerisation. Biochemical Pharmacology 52, 551–559. PubMed

Raz V, Ecker JR. 1999. Regulation of differential growth in the apical hook of Arabidopsis. Development 126, 3661–3668. PubMed

Raz V, Koornneef M. 2001. Cell division activity during apical hook development. Plant Physiology 125, 219–226. PubMed PMC

Rigas S, Ditengou FA, Ljung K, Daras G, Tietz O, Palme K, Hatzopoulos P. 2013. Root gravitropism and root hair development constitute coupled developmental responses regulated by auxin homeostasis in the PubMed

Rojas-Pierce M, Titapiwatanakun B, Sohn EJ et al. 2007. Arabidopsis P-glycoprotein19 participates in the inhibition of gravitropism by gravacin. Chemistry & Biology 14, 1366–1376. PubMed

Růžička K, Ljung K, Vanneste S, Podhorská R, Beeckman T, Friml J, Benková E. 2007. Ethylene regulates root growth through effects on auxin biosynthesis and transport-dependent auxin distribution. The Plant Cell 19, 2197–2212. PubMed PMC

Savaldi-Goldstein S, Baiga TJ, Pojer F et al. 2008. New auxin analogs with growth-promoting effects in intact plants reveal a chemical strategy to improve hormone delivery. Proceedings of the National Academy of Sciences, USA 105, 15190–15195. PubMed PMC

Schreiber KJ, Nasmith CG, Allard G, Singh J, Subramaniam R, Desveaux D. 2011. Found in translation: high-throughput chemical screening in PubMed

Schwark A, Schierle J. 1992. Interaction of ethylene and auxin in the regulation of hook growth I the role of auxin in different growing regions of the hypocotyl hook of

Shivaraj Y, Naveen MH, Vijayakumar GR, Kumar DBA. 2013. Design, synthesis and antibacterial activity studies of novel quinoline carboxamide derivatives. Journal of the Korean Chemical Society 57, 241–245.

Smet D, Žádníková P, Vandenbussche F, Benková E, Van Der Straeten D. 2014. Dynamic infrared imaging analysis of apical hook development in PubMed

Stepanova AN, Robertson-Hoyt J, Yun J, Benavente LM, Xie DY, DoleZal K, Schlereth A, Jurgens G, Alonso JM. 2008. TAA1-mediated auxin biosynthesis is essential for hormone crosstalk and plant development. Cell 133, 177–191. PubMed

Stepanova AN, Yun J, Likhacheva AV, Alonso JM. 2007. Multilevel interactions between ethylene and auxin in Arabidopsis roots. Plant Cell 19, 2169–2185. PubMed PMC

Surpin M, Rojas-Pierce M, Carter C, Hicks GR, Vasquez J, Raikhel NV. 2005. The power of chemical genomics to study the link between endomembrane system components and the gravitropic response. Proceedings of the National Academy of Sciences, USA 102, 4902–4907. PubMed PMC

Suttle JC. 1988. Effect of ethylene treatment on polar IAA transport, net IAA uptake and specific binding of N-1-naphthylphthalamic acid in tissues and microsomes isolated from etiolated pea epicotyls. Plant Physiology 88, 795–799. PubMed PMC

Suzumori N, Burns KH, Yan W, Matzuk MM. 2003. RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome degradation pathway. Proceedings of the National Academy of Sciences, USA 100, 550–555. PubMed PMC

Tan X, Calderón Villalobos LI, Sharon M, Zheng C, Robinson CV, Estelle M, Zheng N. 2007. Mechanism of auxin perception by the TIR1 ubiquitin ligase. Nature 446, 640–645. PubMed

Tanimoto M, Roberts K, Dolan L. 1995. Ethylene is a positive regulator of root hair development in PubMed

Tognolli M, Penel C, Greppin H, Simon P. 2002. Analysis and expression of the class III peroxidase large gene family in PubMed

Trott O, Olson AJ. 2010. AutoDock Vina: improving the speed and accuracy of docking with a new scoring function, efficient optimization and multithreading. Journal of Computational Chemistry 31, 455–461. PubMed PMC

Tsukagoshi H, Busch W, Benfey PN. 2010. Transcriptional regulation of ROS controls transition from proliferation to differentiation in the root. Cell 143, 606–616. PubMed

Ulmasov T, Hagen G, Guilfoyle TJ. 1997. ARF1, a transcription factor that binds to auxin response elements. Science 276, 1865–1868. PubMed

Van de Poel B, Van Der Straeten D. 2014. 1-Aminocyclopropane-1-carboxylic acid (ACC) in plants: more than just the precursor of ethylene!Frontiers in Plant Science 5, 640. PubMed PMC

Vandenbussche F, Callebert P, Zadnikova P, Benkova E, Van Der Straeten D. 2013. Brassinosteroid control of shoot gravitropism interacts with ethylene and depends on auxin signaling components. American Journal of Botany 100, 215–225. PubMed

Vandenbussche F, Petrasek J, Zadnikova P et al. 2010. The auxin influx carriers AUX1 and LAX3 are involved in auxin-ethylene interactions during apical hook development in PubMed

Vandenbussche F, Suslov D, De Grauwe L, Leroux O, Vissenberg K, Van Der Straeten D. 2011. The role of brassinosteroids in shoot gravitropism. Plant Physiology 156, 1331–1336. PubMed PMC

Van Eerd LL, Stephenson GR, Kwiatkowski J, Grossmann K, Hall JC. 2005. Physiological and biochemical characterization of quinclorac resistance in a false cleavers ( PubMed

Verbelen JP, De Cnodder T, Le J, Vissenberg K, Baluska F. 2006. The root apex of PubMed PMC

Woznica Z, Nalewaja JD, Messersmith CG, Milkowski P. 2003. Quinclorac efficacy as affected by adjuvants and spray carrier water. Weed Technology 17, 582–588.

Wu G, Cameron JN, Ljung K, Spalding EP. 2010. A role for ABCB19-mediated polar auxin transport in seedling photomorphogenesis mediated by cryptochrome 1 and phytochrome B. The Plant Journal 62, 179–191. PubMed

Yang H, Murphy AS. 2009. Functional expression and characterization of Arabidopsis ABCB, AUX 1 and PIN auxin transporters in PubMed

Yang SF, Hoffman NE. 1984. Ethylene biosynthesis and its regulation in higher plants. Annual Review of Plant Physiology and Plant Molecular Biology 35, 155–189.

Zadnikova P, Petrasek J, Marhavy P et al. 2010. Role of PIN-mediated auxin efflux in apical hook development of PubMed

Zadnikova P, Smet D, Zhu Q, Van Der Straeten D, Benkova E. 2015. Strategies of seedlings to overcome their sessile nature: auxin in mobility control. Frontiers in Plant Science 6, 218. PubMed PMC

Zhao Y, Dai X, Blackwell HE, Schreiber SL, Chory J. 2003. SIR1, an upstream component in auxin signaling identified by chemical genetics. Science 301, 1107–1110. PubMed