On Monday, June 17, SIVB held an oral presentation competition for post-doctoral scientists. The top three contestants had been chosen to deliver talks based on the quality of their abstracts. All the presentations were good, and the contestants each fielded questions from the audience and our judges. Since the scientific topics were diverse it was difficult to compare the topics and choose a winner; however, our judges Dr. Nancy Reichert, Dr. C. S. Prakash Kumar, and Dr. Lisa Lee were able to render a final decision. They ranked Rakesh Kumar Sinha from Agriculture and Agri-Food Canada for 3rd prize, Zhigang Li from Clemson University for 2nd prize, and Trudi Grant from the Ohio State University for 1st prize. Plaques and cash awards were made at our Plant Section Business Meeting. We encourage all qualified scientists to enroll in 2014’s competition.
Submitted by Hong Luo
First Place
Dissection of the Gmubi Promoter Intron Reveals Possible Regulatory Elements that Affect Promoter Activity and Transgene Expression
Trudi Grant
The soybean ubiquitin promoter, Gmubi, is an intron-containing polyubiquitin promoter that expresses at high levels in many different soybean tissues. Typically recognized for their function in messenger RNA processing and stability, introns may also contain enhancer elements that can affect gene expression. Removal of the intron from the Gmubi promoter resulted in reduced levels of gene expression, which suggest an important role for the Gmubi intron in promoter activity. Various intron derivatives were evaluated using transient expression of GFP in lima bean cotyledons. Tetrameric repeats of small intron fragments were placed upstream of a minimal CaMV35S core promoter, which was used to regulate the green fluorescent protein. Tetramers were also cloned within a modified, native intron, which was then placed downstream of Gmubi and CaMV35S core promoters. Intron derivative constructions were introduced into lima bean cotyledons via particle bombardment and GFP expression was evaluated at peak expression times. Intron fragments, used as tetramers upstream of minimal promoters, regulated GFP expression at least two times higher than levels obtained with the CaMV35S core promoter, with some fragment tetramers yielding up to eighty times higher expression. Tetrameric intronic fragments, cloned within an intron, also demonstrated increased GFP expression up to four times higher than Gmubi alone and up to forty times CaMV35S alone. These intron fragments likely contain regulatory elements that could provide increased expression. The use of intron regulatory elements provides an additional tool for increasing transgene expression.
Trudi Grant. The Ohio State University, OARDC, 1680 Madison Avenue, Wooster, OH. In Vitro Cellular and Developmental Biology, 49:S33, 2013
Second Place
GmCPI1, a Soybean Cysteine Protease Inhibitor Is Involved in Plant Development and Response to Biotic Stress
Zhigang Li
Proteases as secreted extracellular proteolytic enzymes in many insects and pathogenic microorganisms play important roles in pathogenesis, and are essential for the maintenance and survival of their hosts. Cysteine protease inhibitors are among the effective antidigestive compounds produced in plants to fight against herbivory or pathogenic infection. We have cloned a soybean cysteine protease inhibitor gene GmCPI1 from a nematode-resistant genotype. Transgenic Arabidopsis plants overexpressing GmCPI1 exhibited dramatically enhanced resistance against pests. Transient essay using soybean root transformation demonstrated that compared to wild-type control plants, transgenic soybean roots overexpressing GmCPI1 had a 60% decrease in nematode infection. In addition, overexpression of GmCPI1 led to dramatically enhanced plant growth associated with modified global gene expression profiles. These data point to the great potential of using similar strategy to improve other food plants & economically important crops for enhanced pest and disease resistance as well as seed and biomass yield, contributing to agricultural production.
Zhigang Li. Department of Genetics and Biochemistry, Clemson University, 110 Biosystems Research Complex, Clemson, SC 29634. In Vitro Cellular and Developmental Biology, 49:S-33, 2013
Third Place
Isolated Microspore Culture in Cereals by Mediating Stresses and Nursing
Rakesh Kumar Sinha
Isolated microspore culture is a double haploid production platform instrumental in breeding programs. Development of microspore into embryo and green plant is dependent on a series of factors. An estimated 50% of the isolated microspore undergoes programme cell death within 24 hours of culture, and few microspores succeed to form scutellar stage embryo in wheat and triticale. Studies were conducted to reduce the frequency of microspore cell death during the early stage of culture, to nurse their embryogenic development and enhance the production of green plants while minimising albinism. Various groups of antioxidants, including reactive oxygen species scavenger dimethyl tyrosine group, and Phytosulfokine-alpha (PSK-) were evaluated in triticale and spring wheat genotypes. We report the number of embryo like structure and green plants were enhanced when induction medium was supplemented with proline (10 mM) or Glutathione (2mM). The use of dimethyl tyrosine labelled organelle targeting peptides, allowing mitochondrial and chloroplast targeted delivery, greatly enhanced frequency of microspore going through embryo like formation and plant production. Complementary to these treatments, we report a dose effect of the nursing PSK-on the number of embryos and the rate of green to albino plant formations, which resulted in an efficient doubled haploid production platform in wheat and triticale.
Rakesh Kumar Sinha. Agriculture and Agri-Food Canada, Lethbridge, T1J 4B1, Alberta, Canada. In Vitro Cellular and Developmental Biology, 49:S33-S34, 2013
