Update:
final results will be posted.
The soybean aphid is the most important arthropod pest of soybean in North America. The prevalence of the aphid in soybean fields has resulted in increased time spent on scouting and the increased use of insecticides as both seed treatments and foliar sprays leading to a significant increase in the cost of production. The current strategy to limit the economic losses caused by the aphid is to increase host plant resistance. The discovery of several aphid resistant genes in various cultivars have greatly aided the process. However, specific soybean aphid biotypes have already been identified around the country that specifically overcome the resistant genes. In order to overcome this adaptation, the goal of this work was to genetically manipulate an important soybean defense regulatory gene, PHYTOALEXIN DEFICIENT4 (PAD4) gene. The aim of the proposal was to develop stable soybean transgenic plants that over-express PAD4 with the aim of observing enhanced resistance against the soybean aphid. Towards this end, the PAD4 gene from soybean was identified based on amino acid sequence similarity to the previously identified PAD4 gene from the model plant Arabidopsis thaliana, primers were developed to isolate the PAD4 gene from soybean plants. The soybean PAD4 gene was isolated from RNA isolated from aphid infested soybean plants. The PAD4 gene was then cloned into a plant transformation vector, p1500GmUbi. The resulting plant transformation vector, pVN001 was isolated in sufficient quantities and sent to the Plant transformation facility run by Dr. John Finer at OARDC. At the plant transformation facility, particle bombardment was used to introduce the gene into soybean embryogenic tissue. Embryogenic tissue from the cultivar Jack was bombarded and 5 putative transformation events were obtained. The T0 transgenic seeds obtained from the plant transformation facility will be evaluated for soybean aphid resistance. Preliminary data obtained from this research has been presented at shop talks and also in regional, national and international conferences.