Department of Biological Sciences


Biological Sciences 


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Faculty Research

John Gray

Associate Professor
Ph.D.: Purdue University, 1992
Postdoc: University of Missouri - Columbia
Undegraduate: University College Cork, Ireland


Office:        WO 3232 
Phone No:  419.530.1537 


Currently, there are two main research foci in my laboratory.  The first project has a plant nutritional focus and the second has a regulomics focus.  In these projects we utilize the model plant systems of Arabidopsis thaliana and Corn (Zea mays).  The Arabidopsis model system provides an excellent means by which we can accelerate the discovery and investigation of traits that would be otherwise difficult or slow to study in crop systems.  The corn model system is of course important because it is the main economic crop in the U.S. and the State of Ohio. Underlying both of the main projects is an interest in elucidating the molecular mechanisms by which plants respond to biotic and abiotic stresses in the environment. 

Plant Nutrition 

Asa result of nutrient deficiencies, plants develop economically undesirable symptoms such as chlorotic or dead plant parts.  Ultimately, this translates into economic losses when plants are discarded.  Plants under stress from nutrient deficiencies exhibit internal changes prior to the display of visual symptoms (the “Hidden Hunger” phenomenon).

The figure above demonstrates the effect of removing the micronutrient boron during growth of the popular horticultural plant Pelargonium (widely known as Geranium)

The main goal of our nutritional research, is to identify molecular markers indicative of a nutrient imbalance using genomics (global analysis of gene expression using microarrays) and proteomics.  Monitoring these markers will permit a plan of nutrient correction before the plants show visual symptoms (and thus help avoid commercial losses).

Arabidopsis thaliana at various stages of growth in a hydroponic system that permits precise control of nutrients available to the root system.

Since the micronutrient Boron (B) was identified as being commonly deficient amongst area growers our first studies have focused on analyzing plant responses to boron stress.  We have adopted a research strategy which utilizes the model plant Arabidopsis thaliana for the discovery of biomarkers linked to boron stress.

This knowledge will then be translated to Pelargonium for which molecular biology resources have never been developed.  This work is conducted in collaboration with Dr. Scott Heckathorn in the Environmental Sciences Department at the University of Toledo and is funded by the U.S.D.A.

Grass Regulomics

Recently our laboratory has embarked on a new and exciting collaborative project funded by the National Science Foundation Plant Genome Research Project (NSF-PGRP).  There are a large group of genes known as transcription factors (TFs) that govern the switching on and off of different pathways in metabolism in different cell types.  This three year project will focus on studying corn (Zea mays) but also other crops including rice, sorghum and sugarcane.  This project has the following main objectives:


1:     Build resources for establishing regulatory networks in the grasses by establishing a grasses TF orfeome collection.

2:Generate antibodies against select maize, sorghum, rice, and sugarcane TFs, and identify direct targets on a genome-wide scale

3:Develop GRASSIUS into a public grass regulatory information service.


GRASSIUS is a publicly accessible database will facilitate the free dissemination of the knowledge gained in this project.  The website can be accessed at


This project also has an undergraduate research component that involves the students enrolled in BIOL 3020 Molecular Genetics Laboratory.  Students use up-to-date Gateway® cloning technology to clone PCR amplified open reading frames of corn TFs into the pENTR/D-TOPO vector.  They annotate the clones with the aid of VectorNTI Advantage ® software and they write individualized lab reports for each clone.  Select students have opportunities to continue this work as undergraduate honors projects in my laboratory.  The goal of this effort is to Foster the Integration of Research with Education (F.I.R.E.)

The corn regulomics project is a collaborative project with Erich Grotewold and Ramana Davuluri at The Ohio State University and is funded by the National Science Foundation (NSF).

Other Interests


Cell Death and Lesion mimic mutations:

I also study a set of mutations in corn and arabidopsis named disease lesion mimic mutations. These mutations cause disease-like symptoms on leaves in the absence of pathogens. At present, not much is known about the mechanism of action of these genes, but they appear to offer a unique opportunity for studying how plants maintain and regulate the integrity of cells. Study of such genes should lead to improved strategies in the development of improved crop varieties.


The use of computers to access and analyze large volumes of DNA sequence data is an important tool for modern molecular biologists.  I employ Database search tools, multiple sequence alignment programs and phylogenetic tree software to construct phylogenetic trees that reveal gene relationships and evolution across species.  Although I use this approach predominantly with plant genes, the universality of this approach has permitted me to interact with other departmental researchers that studying human and nematode genes (see most recent publications). 

  Laboratory location

The PI's laboratory is located in Wolfe Hall - a $23 million addition to the Bowman-Oddy Life Sciences building at the University of Toledo.  In addition to having a modern well equipped molecular biology laboratory the PI has full access to the Plant Science Research Center (PSRC) on the fourth floor of Wolfe Hall.  The PSRC houses modern greenhouse, plant growth chamber and plant tissue culture equipment that facilitate the study of plants year round.  Through the assistance of the Northwest Ohio OARDC research farm located 35 miles south of Toledo a summer maize genetics nursery is maintained each summer.


Publications (Peer reviewed):

Rossig C, Reinbothe C, Gray J, Valdes O, von Wettstein D, Reinbothe S. New functions of the chloroplast Preprotein and Amino acid Transporter (PRAT) family members in protein import. Plant Signal Behav. 2014 Jan 29;9(1). pii: e27693. [Epub ahead of print] Review.

Komuniecki R, Law WJ, Jex A, Geldhof P, Gray J, Bamber B, Gasser RB. Monoaminergic signaling as a target for anthelmintic drug discovery: receptor conservation among the free-living and parasitic nematodes. Mol Biochem Parasitol. 2012 May;183(1):1-7. doi: 10.1016/j.molbiopara.2012.02.001. Epub 2012 Feb 11. Review.

Gray J, Caparrós-Ruiz D, Grotewold E. Grass phenylpropanoids: regulate before using! Plant Sci. 2012 Mar;184:112-20. doi: 10.1016/j.plantsci.2011.12.008. Epub 2011 Dec 20. Review.

He J, Gray J, Leisner S. A Pelargonium ARGONAUTE4 gene shows organ-specific expression and differences in RNA and protein levels. J Plant Physiol. 2010 Mar 1;167(4):319-25. doi: 10.1016/j.jplph.2009.10.004. Epub 2009 Oct 31.

Smith, K.A., Komuniecki, R.W., Ghedin, E., Spiro D., and Gray J. (2007) “Genes encoding putative biogenic amine receptors in the parasitic nematode Brugia malayi”. In Press Invertebrate Neuroscience

Wragg, R.T.,
Hapiak, V.,
Miller, S., B.
Harris, G., P.
Gray, J., 
Komuniecki, P.R.,
 and Komuniecki, R.W.  (2007) Tyramine and octopamine independently inhibit serotonin-stimulated aversive behaviors in Caenorhabditis elegans through two novel amine receptors In press Journal of Neuroscience

Olszewski, M.A., Gray J., and Vestal D.J. (2006) In Silico Genomic Analysis of the Human and Murine Guanylate-Binding Protein (GBP) Gene Clusters (2006) Journal of Interferon and Cytokine Research 26:328–352

Gray J., Wardzala E., Yang M, Reinbothe S., Haller S., and Pauli F. (2004) A small family of LLS1-related non-heme oxygenases in plants with an origin amongst oxygenic photosynthesizers.  Plant Mol. Biol.,.  54(1) 39-54

Yang M., Wardzala E., Johal G.S., and Gray J.  (2004) The wound-inducible Lls1 gene from maize is an ortholog of the Arabidopsis Acd1 gene, and the LLS1 protein is present in non-photosynthetic tissues.  Plant Mol. Biol., 54(2) 175-191

Reinbothe S., Quigley F., Gray J., Schemenewitz A., and Reinbothe C.  (2004) Identification of plastid envelope proteins required for the import of protochlorophyllide oxidoreductase (POR) A into the chloroplast of barley.  Proc. Natl. Acad. Sci. USA, 101(7) 2197-2202

Gray, J., Janick-Buckner, D., Buckner, B., Close, P., and G.S. Johal.  (2002) "Light-dependent death of maize lls1 cells is mediated by mature chloroplasts.  Plant Physiology 130: 1894-1907

Multani, D.S., Meeley, R.B., Patterson, A.H., Gray, J., Briggs, S.P., and G.S. Johal.  (1998)  Plant-pathogen micro-evolution: molecular basis for the recent origin of a fungal disease in maize.  Proc. Natl.Acad. Sci. USA. 95:1186-1191

Buckner B., Janick-Buckner, D., Gray, J., and G.S. Johal.  (1998)  Cell-death mechanisms in maize.  Trends in Plant Science 3: 218-223.

Gray J., Close, P.S., Briggs, S.P., and G.S. Johal.  (1997).  A novel suppressor of cell death in plants encoded by the Lls1 gene of maize. Cell 89: 25-31.

Gray, J., Gelvin S.B., Meilan, R., and R.O. Morris.  (1996) tRNA is the source of extracellular isopentenyladenine in a Ti-plasmidless strain of Agrobacterium tumefaciens.  Plant Physiology. 110:431-438

Johal, G.S., Gray J., Gruis D., and S.P. Briggs.  (1995) Convergent insights into mechanisms determining disease and resistance response in plant-fungal interactions.  Can. J. Bot.  73 (suppl.1): 468-474.

Lichter, A, Manulis, S., Sagee, O., Gafni,Y.,Gray, J., Meilan, R., Morris, R.O., and I. Barash.  (1995)  Production of cytokinins by Erwinia herbicola pv. gypsophilae and isolation of a cytokinin biosynthetic gene.  Mol. Microbe Plant Interact.  1:114-121

Morris, R.O., Blevins, D.G., Dietrich, J.T., Durley, R.C., Gelvin, S.B., Gray, J., Hommes, N.G., Kaminek, M., Matthews, L.J., Meilan, R., Reinbott, T.M., and L. Sayavedra-Soto.,  (1993) Cytokinins in plant pathogenic bacteria and developing cereal grains.  Aust. Jour. of Plant Physiology 20:261-87

Gray, J., Wang, J., and S.B. Gelvin. (1992) Mutation of the miaA gene of Agrobacterium tumefaciens results in reduced vir gene expression.  J. Bacteriology 174:1086-1098.

Book Chapters

E.Grotewold and J. Gray (2008)  Maize Transcription Factors. In The Maize Handbook Volume 2 – Domestication, Genetics and Genomics. Bennetzen, J. and Hake, S eds., (In Press, Anticipated publication in Mid-2008)

Gray J.  (2003) Paradigms of the Evolution of Programmed Cell Death.  In Programmed Cell Death in Plants.  (Gray J., ed,) Blackwell Publishing, Oxford, UK.

Gray J., and G.S. Johal.  (1998) Programmed Cell Death in Plants, In Arabidopsis. Ann. Plant Reviews Vol I. Anderson M., and J.A. Roberts eds., Sheffield Academic Press. Sheffield, UK

Book Editorship:  Volume editor on review book entitled “Programmed Cell Death in Plants, (Gray J., ed,) Biol. Sci. Series, Roberts, J.A. Usherwood, P.N.R. Series eds. Blackwell Publishing, Oxford, UK. Published 2004.Editorship included writing a peer reviewed book/chapter outline, selecting and inviting chapter authors, editing chapters, writing book introduction and making the book index.

Current Students

Graduate Students:

Tina Agarwal

Rao Xu

Last Updated: 8/16/18