Tim Sherman's Research Area


I am a broadly trained plant physiologist/cell biologist having worked with algal nitrogen metabolism, herbicide mode of action and acquired herbicide resistance, and developmental biology and physiology of parasitic plants.

My current research involves the cell biology and physiology in marine systems, especially of freshwater and marine plants and algae. These organisms are the source of most carbon and nitrogen that is added to food chains in the coastal and freshwater areas. Macroalgae and higher plant representatives of these groups have the additional role of serving as sanctuary for the young of many animal species that share their habitat. In spite of their importance in these ecosystems, there are many gaps in our knowledge regarding their physiology and interaction between these and other organisms in these environments.

I am particularly interested in:

  • molecular interaction between seagrasses and pathogens that have led to massive die-off of seagrass beds in temperate areas around the world,
  • molecular mechanisms of stress tolerance in halophytic algae
  • nitrogen and carbon uptake and metabolism in marine algae and the plant species forming the large off-shore seagrass beds that line the coastal regions of the Gulf of Mexico, and difference between non-indigenous species (NIS) and the native species
  • cellular events involved in interactions between parasitic plants and their plant hosts

Selected Publications

(* indicate undergraduate authors)


Molly M. Miller, Adair L. Raybon, Justin T. Roberts, Valeria M. King, Meghan A. Dean, Caroline J. Polska, Dominika Houserova, Aline Crucello, Emmaline C. Barnhill, Matthew K. Chapman, Alexandra E. Chittams, Adam V. Daniel, Willie N. Dunnam, Angela K. Longo, Marie E. McElyea, Victoria R. Pickle, Aaron T. Realista, Amir N. Sahori, Carlyle G. Smith, Cody M. Stevanus, Anna L. Taylor, Katelyn T. Woddail, Timothy D. Sherman, and Glen M. Borchert. (2018) Identification of microRNAs and simple repeats in the submerged aquatic plant species Hydrilla verticillata and Vallisneria neotropicalis. In review. Aquatic Botany.

Justin T. Roberts, Dillon G. Patterson, Valeria M. King, Shivam V. Amin, Caroline J. Polska, Dominika Houserova, Aline Crucello, Emmaline C. Barnhill, Molly M. Miller, Timothy D. Sherman and Glen M. Borchert (2018). ADAR Mediated RNA Editing Modulates MicroRNA Targeting in Human Breast Cancer Processes 2018, 6, 42; doi:10.3390/pr6050042

G. Borchert, D. Patterson, J. Roberts, V. King, D. Houserova, E. Barnhill, A. Crucello*, C. Polska*, L. Brantley*, G. Kaufman*, M. Nguyen*, M. Santana*, I. Schiller*, J.*, A. Zapata*, M. Miller, T. Sherman, R. Ma, Ho. Zhao, R. Arora*, A. Coley*, M. Zeidan*, M. Tan, and Y. Xi (2017) Human snoRNA-93 is processed into a microRNA-like RNA that promotes breast cancer cell invasion. NPJ Breast Cancer. 3: 25 10.1038/s41523-017-0032-8

D.L. Martin, Y. Chiari, E. Boone, T.D. Sherman, C. Ross, S. Wyllie- Echeverria, J.K. Gaydos, A.A. Boettcher (2016) Functional, Phylogenetic and Host-Geographic Signatures of Labyrinthula spp. Provide for Putative Species Delimitation and a Global-Scale View of Seagrass Wasting Disease.  Estuaries and Coasts39:1403–1421 10.1007/s12237-016-0087-z

A. Garrote-Moreno, A. McDonald, T.D. Sherman, J.L. Sánchez-Lizaso, K.L. Heck, Jr, & J. Cebrian (2015) Short-term impacts of salinity pulses on morphological and functional traits of the seagrasses Thalassia testudinum and Halodule wrightii. Aquatic Botany, 120: 315-321

B.K. Sullivan, T.D. Sherman, V.S. Damare, O. Lilje, and F.H. Gleason (2013) Potential roles of Labyrinthula spp. in global seagrass population declines. Fungal Ecology 6: 1-11

J. D. Husband, R. P. Kiene, T. D. Sherman (2012) Oxidation of dimethylsulfoniopropionate (DMSP) in response to oxidative stress in Spartina alterniflora and protection of a non-DMSP producing grass by exogenous DMSP + acrylate. Environmental and Experimental Botany 79: 44–48
D. J. Shafer, J. E. Kaldy, T. D. Sherman, K. M. Marko (2011) Effects of Salinity on Photosynthesis and Respiration of the Seagrass Zostera Japonica: A Comparison of Two Established Populations in North America. Aquatic Botany 95: 214-220 
D. J. Shafer, S. Wyllie-Echeverria, and T. D. Sherman (2008) The Potential Role of Climate in the Distribution and Growth of the Introduced Seagrass Zostera japonica in North America. Aquatic Botany  89: 297-302 
T. D. Sherman, A. J. Bowling, T. W. Barger and  K. C. Vaughn (2008) The Vestigial Root of Dodder (Cuscuta pentagona) Seedlings. Int. J. Plant Sci. 169(8):998–1012. 
D. J. Shafer, T. D. Sherman, and S. Wyllie-Echeverria, (2007) Do Desiccation Tolerances Control the Vertical Distribution of Intertidal Seagrasses?  Aquatic Botany 87(2): 161-166 
J. Lartigue  and T. D. Sherman (2005) Response of Enteromorpha sp. (Chlorophyceae) to a nitrate pulse: nitrate uptake, inorganic nitrogen storage, and nitrate reductase activity. Marine Ecology Progress Series 292: 147–157 
E. J. Boone, A. A. Boettcher, T. D. Sherman, and J. J. O’Brien (2004) What constrains the geographic and host range of the rhizocephalan Loxothylacus texanus in the wild?  Journal of Experimental Marine Biology and Ecology: 309: 129– 139
J.F. Valentine, E.F. Blythe, S. Madhavan, T.D. Sherman (2004) Effects of simulated herbivory on nitrogen enzyme levels, N-assimilation and N-allocation in Thalassia testudinum. Aquatic Botany: 79: 235–255
J. Lartigue and T. D. Sherman (2002) Field assays for measuring nitrate reductase activity in Enteromorpha sp. (Chlorophyceae), Ulva sp. (Chlorophyceae), and Gelidium sp. (Rhodophyceae), Journal Phycology, 38 (5): 971-982 
T. D. Sherman, W. T. Pettigrew, and K.C. Vaughn  (1999)  Structural and immunological characterization of the Cuscuta pentagona L. chloroplast.  Plant Cell Physiology.  40: 592-603


Current and Pending Funding:

  • NSF-DUE (2010-2012) Integrating genomics and bioinformatics into an ecology and evolution-based undergraduate curriculum  $199,496  [Funded]

Current Graduate Students:

Molly Miller (Ph.D. - Marine Sciences)  Molly's work is funded on an EPA-STAR graduate fellowship.  She is examining how anthropogenic nutrient input Influences plant competitive outcomes and its implications for habitat degradation and community shifts.  

Jeff Zabolotney (M.S. - Biology)  Jeff is finishing up his project, which involved the influence of magnetic fields on algal growth.

Undergraduate and Graduate Students Currently Working in the Lab:

Chi Tran - Chi's project involves creating axenic cultures of Dunaliella spp. These cultures will be used as general resources in collaborative work between my and Dr. Kelly Major's labs.  Chi will also be learning how to do protein isolations and 2-D gel electrophoresis with cultures.

Thomas Hughes - During his Biology Senior Thesis Program project, Thomas worked on the characterization of possible cell wall tunneling bacteria from the leaves of the seagrass Thalassia testudinum.  In this work, he isolated bacteria from the leaves of this seagrass collected from the Perdido Key area.  This work is related to the seagrass" wasting disease" and potential mechanisms of entry into the host leaf tissue used by the pathogen Labyrinthula sp.   He defended his thesis in the spring of 2012.  Thomas is now enrolled in the Juris Doctoral Program at Mississippi College School of Law.  He is interested in pursuing a career in environmental law.

Harmoni Neubert - Harmoni's work was based on the group project she was involved with when she took BLY342 with me.  Her project in my research lab (spring of 2012) examined the salinity tolerance and benzene induced expression of HSP70 in brine shrimp (Artemia).  Harmoni is planning to pursue graduate school doing some sort of medically-oriented research.

Catharine Weber - Catharine was very interested in pursing a career in science policy.  Her project during summer of 2011 allowed her  to delve into the policy and politics of handling an invasive marine plant along the Pacific coast of the U.S.  Her project was titled: "A Microcosm of Environmental Policy Development: Pacific Northwest reaction to Zostera japonica"   Catharine is currently working towards her M.S. in Agricultural Economics at the Univ. of Missouri.

Ashley Ulm - Ashley worked in the lab during the summer of 2010 as an NSF-REU student.  In her project, she worked on the development of a green fluorescent protein transformation system 
for the seagrass pathogen Labyrinthula sp. Ashley is currently working as a research assistant in the division of  Asthma Research in Cincinnati Children's Hospital Medical Center.

Previous Graduate Students:

Jackie Howell (M.S. - Biology) Species Distribution and Hybridization of Sarracenia at Splinter Hill Bog Preserve (2012)  [Co-chaired with Dr. Ashley Morris]

Simmi Yadav (M.S. - Biology)  Immunochemical Characterization of the Cell Wall of Thalassia Testudinum. (2011)

Fui Chi Yap (M.S. - Biology)  Activation of Endothelial Nitric Oxide Synthase Requires Calcium Entry From CaV3.1 (Α1G) T-Type Calcium Channel (2011) [Co-chaired with Dr. Songwei Wu]

Tamil Jones (M.S. Biology) The Role and Regulation of the Phosphohistidine Phosphatase SixA in the Starvation- Stress Response of Salmonella enterica Serovar Typhimurium (2011) [Co-chaired with Dr. Michael Spector]

Deborah Shafer (Ph.D. - Marine Sciences) The Invasive Seagrass Zostera japonica : Distribution, Autecology, and Potential for Expansion (2007)

Anna Penton (M.S. - Biology)  Anna's work centered on community structure across invasive and indigenous aquatic plants.  She will graduate in the fall of 2006 and will work in a medical research lab here at the Univ. of South Alabama. (2006)

Joe James (M.S. - Biology). Molecular Characterization of Diversity of Bacteria Associated with Seagrass Transplanting Units and Seagrass Bed Sediments. (2004)

Julien Lartigue (Ph.D. - Marine Sciences) Nitrate Uptake, Nitrogen Storage, and Nitrate Reductase Activity in Estuarine Enteromorpha Sp. (Chlorophyceae) (2002)

Fennel Blythe (M.S. - Biology) Nitrogen Uptake, Assimilation, and Translocation in the Seagrass,Thalassia Testudinum (1996)