James N. Siedow

Professor Emeritus of Biology

130 Science Drive, 3105 French Science Centre, Durham, NC 27708
Campus Box: 
Duke Box 90338, Department of Biology, Durham, NC 27708
(919) 684-5445
Physiological, biochemical and molecular studies of plant oxidative processes. I suspended the operation of my laboratory about eight years ago. Historically, the research in my laboratory looked at metabolic processes related to aerobic respiration in plants and fungi. Specifically, this research involves isolating and characterizing the structural and regulatory features of the cyanide-resistant "alternative" oxidase associated with all plant and many fungal mitochondria. The mechanism of action of a regulatory sulfhydryl-disulfide system on the alternative oxidase and its interplay with the activating effects of alpha-keto acids are currently under study, as is the characterization of structural features of the alternative protein and its active site. Comparative studies of the plant and fungal alternative oxidases have indicated a common structural framework but distinctly different regulatory features. This research involves the application of standard biochemical approaches, including chemical cross-linking, immunochemical technologies, and electrochemical methodologies. These approaches are further complemented by the use of site-directed mutagenesis of the alternative oxidase expressed in both the bacterium E. coli and transgenic Arabidopsis thaliana. Transformed Arabidopsis having over- and underexpressed wild-type, as well as altered forms of the alternative oxidase lacking normal regulatory control have been developed and are being used to characterize the role played by the alternative oxidase in response to different developmental and environmental circumstances, including extremes of temperature, pathogen infection, and nutrient limitations.


  • Ph.D., Indiana University at Indianapolis 1972

  • B.A., University of Texas, Austin 1969

Siedow, J. N. “ATP Synthesis: Mitochondrial Cyanide-Resistant Terminal Oxidases.” In Encyclopedia of Biological Chemistry: Second Edition, 145–48, 2013. https://doi.org/10.1016/B978-0-12-378630-2.00285-1. Full Text

Wu, Feihua, Yuan Chi, Zhonghao Jiang, Yuanyuan Xu, Ling Xie, Feifei Huang, Di Wan, et al. “Hydrogen peroxide sensor HPCA1 is an LRR receptor kinase in Arabidopsis.Nature 578, no. 7796 (February 19, 2020): 577–81. https://doi.org/10.1038/s41586-020-2032-3. Full Text

Jiang, Zhonghao, Xiaoping Zhou, Ming Tao, Fang Yuan, Lulu Liu, Feihua Wu, Xiaomei Wu, et al. “Plant cell-surface GIPC sphingolipids sense salt to trigger Ca2+ influx.Nature 572, no. 7769 (August 2019): 341–46. https://doi.org/10.1038/s41586-019-1449-z. Full Text

Liu, Lulu, Zhonghao Jiang, Shu Zhang, Hongyan Zhao, Weiguang Yang, James N. Siedow, and Zhen-Ming Pei. “Both NaCl and H2O2 Long-Term Stresses Affect Basal Cytosolic Ca2+ Levels but Only NaCl Alters Cytosolic Ca2+ Signatures in Arabidopsis.Frontiers in Plant Science 9 (January 2018): 1390. https://doi.org/10.3389/fpls.2018.01390. Full Text

Yuan, F., H. Yang, Y. Xue, D. Kong, R. Ye, C. Li, J. Zhang, et al. “Corrigendum: OSCA1 mediates osmotic-stress-evoked Ca(2+) increases vital for osmosensing in Arabidopsis.Nature, February 2015.

Yuan, Fang, Huimin Yang, Yan Xue, Dongdong Kong, Rui Ye, Chijun Li, Jingyuan Zhang, et al. “OSCA1 mediates osmotic-stress-evoked Ca2+ increases vital for osmosensing in Arabidopsis.Nature 514, no. 7522 (October 2014): 367–71. https://doi.org/10.1038/nature13593. Full Text

Wu, Xiaomei, Fei-Hua Wu, Xiaoqiang Wang, Lilin Wang, James N. Siedow, Weiguo Zhang, and Zhen-Ming Pei. “Molecular evolutionary and structural analysis of the cytosolic DNA sensor cGAS and STING.Nucleic Acids Res 42, no. 13 (July 2014): 8243–57. https://doi.org/10.1093/nar/gku569. Full Text

Florez-Sarasa, Igor, Jaume Flexas, Allan G. Rasmusson, Ann L. Umbach, James N. Siedow, and Miquel Ribas-Carbo. “In vivo cytochrome and alternative pathway respiration in leaves of Arabidopsis thaliana plants with altered alternative oxidase under different light conditions.Plant, Cell & Environment 34, no. 8 (August 2011): 1373–83. https://doi.org/10.1111/j.1365-3040.2011.02337.x. Full Text

Møller, Ian M., Allan G. Rasmusson, James Jim N. Siedow, and Greg C. Vanlerberghe. “The product of the alternative oxidase is still H2O.Archives of Biochemistry and Biophysics 495, no. 1 (March 2010): 93–94. https://doi.org/10.1016/j.abb.2009.12.027. Full Text

Rhoads, David M., Ann L. Umbach, Chalivendra C. Subbaiah, and James N. Siedow. “Mitochondrial reactive oxygen species. Contribution to oxidative stress and interorganellar signaling.Plant Physiology 141, no. 2 (June 2006): 357–66. https://doi.org/10.1104/pp.106.079129. Full Text

Umbach, Ann L., Vicki S. Ng, and James N. Siedow. “Regulation of plant alternative oxidase activity: a tale of two cysteines.Biochimica Et Biophysica Acta 1757, no. 2 (February 2006): 135–42. https://doi.org/10.1016/j.bbabio.2005.12.005. Full Text


Selected Grants

High-performance Computing System for Bioinformatics awarded by National Institutes of Health (Advisor). 2009 to 2010

Studies of the Cyanide-Resistant Alternative Oxidase awarded by National Science Foundation (Principal Investigator). 1997 to 2005

Iain Hamilton Sculpture Events awarded by The Mary Duke Biddle Foundation (Principal Investigator). 2002 to 2003

Oxygen Isotope Fractionation by the Cyanide-Resistant Oxidase in Plants awarded by Cooperative State Research Service (CSRS) (Principal Investigator). 1999 to 2002

BioTerrorism Workshop awarded by Army Research Office (Principal Investigator). 2002

Acquisition of Growth Chambers for the National Phytotron awarded by National Science Foundation (Co-Principal Investigator). 1994 to 1999

Oxygen Isotype Fractionation in Plant Mitochondria awarded by Cooperative State Research Service (CSRS) (Principal Investigator). 1994 to 1999

Continuation of Operations of the National Phytotron awarded by National Science Foundation (Co-Principal Investigator). 1995 to 1999

Studies of the Plant Cyanide - Resistant Alternative Oxidase awarded by National Science Foundation (Principal Investigator). 1997 to 1998

Studies of the Cyanide-resistant Respiratory Pathways awarded by National Science Foundation (Principal Investigator). 1994 to 1997