SIVB held a formal poster competition during the 2014 World Forum on Biology in Savannah, Georgia. Poster authors who were interested submitted their work at the start of the meeting and the judges reviewed their posters during the poster session to determine prize winners. Rinnie Rodenius, of University of Florida won for 1st prize, Sarah Poynter, Wilfrid Laurier University 2nd prize, and Steven Samuels, Tuskegee University 3rd prize. Awards were presented at the SIVB Business Meeting.
Submitted by the Business Office
Effect of Pruning on Root Regrowth of In Vitro Cultured Dendrophylax Lindenii Seedlings
Dendrophylax lindenii, the ghost orchid, is a leafless epiphytic orchid. The species ranges from southern Florida, Cuba and the Caribbean and is noted for its striking white flowers. Morphologically, plants consist of photosynthetic roots attached to a reduced stem having highly reduced scale-like leaves. Plantlets have been observed to regenerate from broken or damaged roots but this is not well documented. Likewise, little is known of the root regeneration from the reduced stem of the ghost orchid. An experiment was designed to: 1) examine the effects of root pruning on subsequent root regrowth of Dendrophylax lindenii seedlings; 2) examine the anatomical origin of regenerated roots; and 3) compare the effects of two orchid media PhytoTechnology Laboratories P723 supplemented with 3% (w/w) banana powder and PhytoTechnology Laboratories P748 on root regrowth following pruning. Roots of the seedlings were pruned to 0.5 or 1.0 cm in length and cultured on the two media for 14 weeks. Ghost Orchid seedlings displayed the capacity to regenerate new roots from the central stem following pruning with maximum root regeneration and length observed on P723 medium. The results are useful for producing smaller roots on older seedlings which would facilitate root attachment to substrates during greenhouse acclimatization.
Rinnie Rodenius, University of Florida, PO Box 110675, Gainesville, FL 32611. In Vitro Cellular and Developmental Biology, 50:S31, 2014
The Innate Antiviral Effects of Extracellular Viral dsRNA in Rainbow Trout Cells
Almost all viruses produce double-stranded (ds) RNA sometime in their replicative cycle. Viral dsRNA is a potent trigger of innate immune responses in animals; activating the keystones of innate immunity, type I interferons (IFNs) and interferon stimulated genes (ISGs). DsRNA molecules produced in a cell during a virus infection are released into the extracellular environment during lytic viral infections. The effects of extracellular dsRNA in mammals are just beginning to be elucidated and almost nothing is known of its effects in fish. The present study uses both commercially available dsRNA (poly IC) and in vitro transcribed dsRNA molecules, based on the viral hemorrhagic septicemia virus (VHSV) genome sequence, as stimuli to investigate the effects of dsRNA on IFN/ISG production and antiviral effects in fish cells. Using an ISG reporter system, functional IFN assay, antiviral assay, and RT-PCR we have found that extracellular dsRNA, both synthetic and in vitro transcribed, are able to induce innate antiviral responses in the fish cell line, RTG-2. High- and low- molecular weight poly IC and different lengths of in vitro transcribed dsRNA were used to explore length effects. Consistent with previous studies done in mammalian cells we saw a greater magnitude of immune response when cells were stimulated with longer dsRNA molecules.
Saray Poynter, Wilfrid Laurier University, 139 Brighton Street, Waterloo, ON N2J2S7, CANADA. In Vitro Cellular and Developmental Biology, 50:S42, 2014
Engineering Sweetpotato [Ipomoea Batatas (L.) Lam] Expressing Synthetic Lytic Peptide for the Potential Inhibition of Human Immunodeficiency Virus Replication
The development of plants to produce therapeutic compounds can be used to supply low-cost drugs and vaccines for major diseases such as HIV to the developing world. Treatments of infectious diseases in humans and animals have traditionally been targeted by chemically synthesized drugs, with the majority of the burden of cost falling on the individual in need of treatment. With the new revolution of producing therapeutic compounds, such as peptides in plant based systems, the cost of production is dramatically decreased. The action of most antimicrobial peptides induces membrane defects such as phase separation or membrane thinning, pore formation, and bilayer disruption. Antimicrobial peptides have also been found to target intracellular molecules, such as DNA/RNA or enzymes. Synthetic lytic peptides jc41n and jc41nd, capable of inhibiting the progression of HIV have been developed at Tuskegee University and expressed in sweetpotato. Seven transgenic plantlets were PCR positive using primers specific for the JC genes, and primers targeting the 35S promoter and NOS terminator. The presence of the JC protein from plant extracts are currently being detected by Western blot using antibodies derived from injection of peptide protein in mice. To test efficacy and toxicity, crude and purified sweetpotato extracts showed minimal peptide cytotoxicity in dosing trials using Jurket cells in 4, 8, 12, and 18 hr treatments; prior to downstream dosing tests in mice. Further analysis using Southern blot on genomic DNA from PCR positive transformants, parental non transformed control, and JC plasmids will confirm stable integration of the transgene and gene insertion number by qPCR. Following verification of efficacy and dosing regiments for extracted proteins, confined field trials will test agronomic evaluation and performance to demonstrate plant merit. Successful development and approval of sweetpotato expressing this novel therapeutic compound can be both a powerful tool in treatment of the HIV epidemic, as well as a road map for future treatment of viral mediated diseases.
Steven Samuels, Tuskegee University, 601-C Dexter St, Tuskegee, AL 36088. In Vitro Cellular and Developmental Biology, 50:S64, 2014