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)

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 
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-MRI: Acquisition of a light sheet microscope, PI: Tom Rich ($272,235)

Current Graduate Students:

Caroline Barnes (M.S. student) Caroline's research involves proteomic characterization of mechanisms that extremophilic algae use to survey in environments that are inhospitable to other algal species.  Extremophiles have the ability to grow under acidic or alkaline pH, high or low temperature, high light, or high metal concentrations.  Determination of mechanisms used by these hardy algae may allow for better stress resistant crop species.

Undergraduate and Graduate Students Currently Working in the Lab:

Kindall Calhoun (B.S. Senior Thesis program student) Kindall is using biochemical assays to examine thermal responses of marine fish species to subtle changes in environmental temperatures that are predicted by climate change models.  

Previous 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.  (2018)

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

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)