Professor of Biology
B.S Virginia Polytechnic Institute and State University (1984)
Ph.D. Purdue University (1989)
Postdoctoral Research, Sandoz Agro Inc. (1991)
41 Winston Hall
Current Research Projects
Areas of Interest
Hormone physiology, biochemistry, and molecular biology
The emphasis of research in the Muday lab is the understanding of the hormone signaling and action in two different systems. We are interested in the role of the plant hormone, auxin, in plant growth, development, and response to the environment and the mammalian adipokines, leptin and adiponectin, in control of lipid metabolism. We are interested in the biochemical mechanisms by which these hormones control growth and metabolism and we explore these questions using approaches including genetics, molecular biology, microscopy, and biochemistry. Our interests are not just in the hormonal signaling mechanisms, but also on the physiological consequences of the action of these hormones. We are interested in the role of auxin in controlling root and shoot branching and gravity response. The impact of leptin on metabolism and weight homeostasis as a function of age and gender are of particular interest.
Auxin transport: Auxins reach plant tissues by a unique cell to cell polar transport system. Auxin transport is carefully regulated to allow growth, development, and responses to light and gravity to be precisely controlled. The biochemical mechanisms of auxin transport and the role of transport in plant growth are one focus of research in the laboratory. We are particularly interested in the regulatory mechanisms that allow changes in auxin transport in response to light and gravity vectors in both the plant genetic model, Arabidopsis thaliana, and the crop model of tomato. The regulatory mechanisms of particular interest include phosphorylation signaling, synthesis of endogenous auxin transport inhibitors of the flavonoid class, and interactions between auxin and ethylene signaling.
Leptin signaling: Leptin is an adipokine, which is a signaling molecule secreted by adipocytes that regulates lipid metabolism and controls eating behavior. In most mammals, this hormone is at significantly higher levels in females. We are exploring the molecular mechanisms that lead to this sexual dimorphism and how aging and changing estrogen levels affect leptin levels. We are interested in how estrogen affects leptin synthesis and signaling including the abundance and localization of leptin receptors.
see also [Pubmed List of Papers]
(bold-type-face names are students)
Maloney GS, DiNapoli KT, Muday GK. 2014. The anthocyanin reduced tomato mutant demonstrates the role of flavonols in tomato lateral root and root hair development. Plant Physiol. 2014 Jul 8. pii: pp.114.240507.
Watkins JM, Hechler PJ, Muday GK. 2014. Ethylene-induced flavonol accumulation in guard cells suppresses reactive oxygen species and moderates stomatal aperture. Plant Physiol. 2014 Apr;164(4):1707-17. doi: 10.1104/pp.113.233528.
Lewis DR, Olex AL, Lundy SR, Turkett WH, Fetrow JS, Muday GK. 2013. A Kinetic Analysis of the Auxin Transcriptome Reveals Cell Wall Remodeling Proteins That Modulate Lateral Root Development in Arabidopsis. Plant Cell. 2013 Sep 17.
Sukumar P, Maloney GS, Muday GK. 2013. Localized induction of the ATP-binding cassette B19 auxin transporter enhances adventitious root formation in arabidopsis. Plant Physiol. 2013 Jul;162(3):1392-405.
Muday GK, Rahman A, Binder BM. 2012. Auxin and ethylene: Collaborators or Competitors? Trends in Plant Science, 17: 181-195.
Miller GD, Jenks MZ, Vendela M, Norris JL, Muday GK (2012) Influence of weight loss, body composition, and lifestyle behaviors on plasma adipokines: a randomized weight loss trial in older men and women with symptomatic knee osteoarthritis. J Obes. 2012;2012:708505. doi: 10.1155/2012/708505. Epub 2012 Dec 26.
Chae K, Isaacs CG, Reeves PH, Maloney GS, Muday GK, Nagpal P, Reed JW. 2012. Arabidopsis SMALL AUXIN UP RNA63 promotes hypocotyl and stamen filament elongation. Plant J. 2012 Aug;71(4):684-97.
Grunewald W, De Smet I, Lewis DR, Löfke C, Jansen L, Goeminne G, Vanden Bossche R, Karimi M, De Rybel B, Vanholme B, Teichmann T, Boerjan W, Van Montagu MC, Gheysen G, Muday GK, Friml J, Beeckman T. 2012. Transcription factor WRKY23 assists auxin distribution patterns during Arabidopsis root development through local control on flavonol biosynthesis. Proc Natl Acad Sci U S A. 2012 Jan 31;109(5):1554-9.
Fernandez-Marcos M, Sanz L., Lewis DL, Muday GK, Lorenzo O. 2011. Nitric oxide causes root apical meristem defects and growth inhibition while reducing PIN1-dependent acropetal auxin transport. PNAS 1108644108
Lewis DR, Negi S, Sukumar P, Muday GK. 2011. Ethylene inhibits lateral root development and enhances IAA transport by altered expression and localization of auxin transport proteins. Development 138: 3485-3495.
Lewis DR, Ramirez MV, Miller ND, Keith R, Helm R, Winkel BSJ, Muday GK. 2011. Auxin and ethylene induce distinct flavonol accumulation patterns through independent transcriptional networks: Plant Physiol. 156: 144-164
Zheng X, Miller ND, Lewis DR, Muday GK, Spalding EP, Vierstra RD. 2011. The F-box protein AUXIN-UPREGULATED1 regulates the cross talk between auxin transport and cytokinin signaling during plant root growth. Plant Physiol. 156: 1878-1893.
Negi S, Sukumar P, Liu X, Cohen JD, Muday GK. 2010. Genetic dissection of the role of ethylene in regulating auxin dependent lateral and adventitious root formation in tomato. Plant Journal 61: 3-15
Baskin TI, Peret B, Baluška F, Benfey PN, Bennett M, Forde BG, Gilroy S, Helariutta Y, Hepler PK, Leyser O, Masson PH, Muday GK, Murphy AS, Poethig S, Rahman A, Roberts K, Scheres B, Sharp RE, Somerville C. Shootward and rootward: peak terminology for plant polarity. Trends Plant Sci. 2010 Nov;15(11):593-4.
Chen Z, Noir S, Kwaiitaal M, Hartmann HA, Wu M-J, Mudgel Y, Sukumar P, Muday GK, Panstruga R, Jones AM. 2009. Two seven-transmembrane domain MLO proteins co-function in root Thigmomorphogenesis. Plant Cell: 21:1972-1991.
Lewis DR and Muday GK. 2009. Measurement of auxin transport in Arabidopsis thaliana Nature Protocols: 4: 437-451.
Sukumar, P, Edwards, KS, Rahman, A, and DeLong, A, and Muday, GK. 2009. PINOID kinase regulates root gravitropism through modulation of PIN2-dependent basipetal auxin transport in Arabidopsis thaliana. Plant Physiol: 150: 722-735.
Negi S, Ivanchenko MG, Muday GK. 2008. Ethylene regulates lateral root formation and auxin transport in Arabidopsis thaliana. Plant J. 55: 175-187
Ivanchenko MG, Muday GK, Dubrovsky JG. 2008. Ethylene-auxin interactions regulate lateral root initiation and emergence in Arabidopsis thaliana. Plant J. 55: 335-347
Buer CS, Muday GK, Djordjevic MA. 2008. Implications of long-distance flavonoid movement in Arabidopsis thaliana. Plant Signaling and Behavior: 3: 415-417
Muday GK and Rahman A. 2007. Auxin transport and the integration of gravitropic growth. In Plant Tropisms: eds Gilroy, S and Masson, P, Blackwell Publishing pp 47-78.
Buer CS, Muday, GK, Djordjevic MA. 2007. Flavonoids are transported long distances in Arabidopsis. Plant Physiol. 145: 478-490.
Muday GK, Brady, SR, Argueso, C., Deruère, J, Kieber, JJ, and 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
Buer CS, Sukumar P, and Muday GK. 2006. Ethylene induced flavonoid synthesis modulates root gravitropism. Plant Physiology: 140: 1384-1396
Sibout R, Sukumar P, Hettiarachchi C, Holm M, Muday GK and Hardtke CS. 2006. Opposite root growth phenotypes of hy5 vs. hy5 hyh correlate with increased constitutive auxin signaling. Plos Genetics: In press
Sieberth, LE, Muday, GK, King, EJ, Benton, G, Kim, S, Metcalf, KE, Myers, L, and Seamen, E (2006) Scarface encodes an ARF-GAP that is required for normal auxin efflux and vein patterning in Arabidopsis. Plant Cell 18: 1396-1411
Perera IY, Hung C-Y, Brady S, Muday GK, Boss WF (2006) A universal role for inositol 1,4,5-trisphosphate-mediated signaling in plant gravitropism. Plant Physiol. 140: 746-760.
Nadella V, Shipp MJ, Muday GK, Wyatt SE. 2006. Evidence for altered polar and lateral auxin transport in the gravity persistent signal (gps) mutants of Arabidopsis. Plant, Cell and Environ. 29: 682-690
Poupart J, Rashotte AM, Muday GK, Waddell CS. 2005. The rib1 mutant of Arabidopsis has alterations in IBA transport, hypocotyl elongation and root architecture. Plant Physiol. 139: 1460-1471
Buer CS and Muday GK. 2004. The transparent testa4 mutation prevents flavonoid synthesis and alters auxin transport and the response of Arabidopsis roots to gravity and light. Plant Cell, 16:1191-1205
Sun H, Basu S, Brady SR, Luciano RL, and Muday GK. 2004. Interactions between auxin transport and the actin cytoskeleton in developmental polarity of Fucusdistichus embryos in response to light and gravity. Plant Physiol.: 135:266-278
Boa F, Shen J, Brady SR, Muday GK, Asami T, and Yang Z. 2004. Brassinosteroids interact with auxin to promote lateral root development in Arabidopsis. Plant Physiol. 134:1624-1631