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Stanley J Roux Jr

Professor, Distinguished Teaching Professor Emeritus
Molecular Biosciences


Phone: 512-471-1074

Office Location

Postal Address
205 W 24TH ST
AUSTIN, TX 78712

Research Summary:

We are studying how the stimuli of light and gravity alter patterns of plant development. In our studies of light-induced responses we have found that certain apyrases (NTPDases), whose expression is strongly regulated by the photoreceptor phytochrome, can modulate the levels of extracellular ATP [eATP], and that, surprisingly, changes in [eATP] can influence hormone transport, the growth of plant cells and organs (including pollen tubes, root hairs, hypocotyls, roots and leaves), wound responses, and toxin resistance in Arabidopsis and other plants. This indicates that eATP, which is a physiological regulator in animals, also influences plant growth and development. For our gravitational studies we are using two model systems, Arabidopsis and spores of the fern Ceratopteris richardii. In these plants, we study how gravity-induced gradients of eATP help mediate gravity-induced growth patterns, such as root and shoot gravitropism in Arabidopsis and polarized growth in Ceratopteri spores. In both plants, the activity of apyrases plays a major role in regulating the [eATP] and cellular growth. Specific apyrases function both in the nucleus, where they impact nucleotide concentrations and gene expression, and in the wall, where they hydrolyze ATP, and thus help control the [eATP]. We are using genetic and biochemical approaches to document the signaling steps whereby apyrases and eATP regulate cell growth. Because this regulation includes promoting an expanded root system architecture and increased seed yield in crop plants, our current focus is elucidating the molecular mechanisms by which apyrases control these events. 


2020. McWhite C, Papoulas O, Drew K, Cox R, June V, Dong O, Kwon T, Wan C, Salmi M, Roux SJ, Browning K, Ronald P, Marcotte E. 2020. A pan-protein compex map reveals deep conservation and novel assemblies. Cell 181: 460-474.

2019. Veerappa R, Slocum RD, Siegenthaler A, Wang J, Clark G, Roux SJ. 2019. Ectopic expression of a pea apyrase enhances root system architecture and drought survival in Arabidopsis and soybean. Plant Cell Environ 42: 337-353. DOI: 10.1111/pce.13425.

2018. Clark G, Roux SJ. 2018. Role of Ca2+ in mediating plant responses to extracellular ATP and ADP. International J Molec. Sci 19, article number 3590. DOI: 10.3390/ijms19113590.

2018. Wang J, Song J, Clark G, Roux SJ. 2018. ANN1 and ANN2 function in post-phloem sugar transport in root tips to affect primary root growth. Plant Physiology 178: 390-401. DOI: 10.1104/pp.18.00713.

2018. Cannon AE, Salmi ML, Cantero A, Roux SJ. Generation of transgenic spores of the fern Ceratopteris richardii to anallyze Ca2+ transport dynamics during gravity-directed polarization. IN: Current Advances in Fern Research (Ed. Elena M. Fernandez Gonzalez), Springer International Publishing AG.

2017. Park J, Salmi ML, Wan Salim WWA, Rademacher A, Wickizer B, Schooley A, Benton J, Catero A, Argote PF, Ren M, Zhang M, Porterfield DM, Ricco AJ, Roux SJ, Rickus JL. An autonomous lab on a chip for space flight calibration of gravity-induced transcellular calcium polarization in single-cell fern spores. Lab on a Chip 17: 1095-1103.

2016. Tripathy M, Clark G, Roux SJ. 2016. Apyrase inhibitors enhance the ability of diverse fungicides to inhibit the growth of different plant pathogenic fungi. Molecular Plant Pathology. DOI : 10.1111/mpp.12458.

2016. Clark G, Russell J, Enyeart P, Gracia B, Wessel A, Jarmoskaite I, Polioudakis D, Stuart Y, Gonzalez T, MacKrell A, Rodenbusch S, Stovall GM, Beckham JT, Montgomery M, Tasneem T, Jones J, Simmons S, Roux S. 2016. Science Educational Outreach Programs That Benefit Students and Scientists. PLOS Biology. DOI:10.1371/journal.pbio.1002368.

2015. Vanegas DC, Clark G, Cannon AE, Roux S, Chaturvedi P, McLamore ES. 2015. A self-referencing biosensor for real-time monitoring of physiological ATP transport in plant systems. Biosens Bioelectron. 74: 37-44.

2015. Cannon AE, Salmi ML, Bushart TJ, Roux SJ. 2015. Studying molecular changes during gravity perception and response in a single cell. Methods Mol Biol. 1309:199-207.

2015. Chiu T-Y, Lao J, Manalansan B, Loqué, Roux SJ, Heazlewood JL. 2015. Biochemical characterization of Arabidopsis APYRASE family reveals their roles in regulating endomembrane NDP/NMP homeostasis. Biochem J. 472: 43-54.

2015. Wang X, Ma X, Wang H, Li B, Clark G, Guo Y, Roux S, Sun D, Tang W. 2015. Proteomic study of microsomal proteins reveals a key role for Arabidopsis Annexin 1 in mediating heat stress-induced increase in intracellular calcium levels. Molecular & Cellular Proteomics 14: 686-694.

2015. Yang X, Wang B, Farris B, Clark G, Roux SJ. 2015. Modulation of root skewing in Arabidopsis by apyrases and extracellular ATP.  Plant & Cell Physiol. 56: 2197-2206.

2014 Lim MH, Wu J, Yao JC, Gallardo IF, Dugger JW, Webb LJ, Huang J, Salmi ML, Song J, Clark G, Roux SJ, Apyrase suppression raises extracellular ATP levels and induces gene expression and cell wall changes characteristic of stress responses. Plant Physiol 164: 2054-2067

2013 Bushart TJ, Cannon AE, Ul Haque A, San Miguel P, Mostajeran K, Clark GB, Porterfield DM, Roux SJ, RNA-seq analysis identified potential modulators of gravity response in spores of Ceratopteris (Parkeriaceae): Evidence for modulation by calcium pumps and apyrase activity, Am J Bot 100: 161-174

2012 Liu X, Wu J, Clark G, Lundy S, Lim M, Arnold D, Chan J, Tang W, Muday GK, Gardner G, Roux SJ, Role for apyrases in polar auxin transport in Arabidopsis, Plant Physiol 160: 1985-95

2011 Salmi M, ul Haque A, Bushart TJ, Stout SC, Roux SJ, Porterfield DM, Changes in gravity rapidly alter the magnitude and direction of a cellular calcium current, Planta 233: 911-920

2011 Clark G, Fraley D, Steinebrunner I, Cervantes A, Onyirimba J, Liu A, Torres T, Tang W, Kim J, Roux SJ, Extracellular nucleotides and apyrases regulate stomatal aperture in Arabidopsis1, Plant Physiology 156: 1740-53 view

2010 Clark G, Torres J, Finlayson S., Guan X, Handley C, Lee J, Kays J, Chen ZJ, Roux SJ, Apyrase (NTPDase) and extracellular nucleotides regulate cotton fiber elongation in cultured ovules, Plant Physiology 152: 1073-83