Updated October 30, 2017:
Little progress has been made in the last 6 months. To recap from the November 2011 report, transformed soybean cultivars containing silenced GmNDR a and b genes were inoculated in the greenhouse with two races of Phytophthora sojae, Rps1-k and Rps1-a. Transformed cultivars containing resistance to Rps1-k and Rps1-a were not affected in their reaction to these races. However, transformed cultivars susceptible to these races, proved to more susceptible. This was an opposite reaction to initial results which showed that silencing GmNDR or GmRIN improved the resistance to P. sojae. No further explanation of this opposite has been offered in any follow-up studies.
Problems have been overcome, since reported 6 months ago, on the transformation of soybean plants with over-expression for GmRINb and also with the two GmNDR genes. Constructs of both genes have been developed and vectors generated, that were in turn, inoculated into soybean plants in the greenhouse. However, the results are yet forthcoming.
Minor progress has been made in the sub-objective to study the interaction between GmRIN and GmNDR to Phytophthora sojae elicitors. A construct of Avr1b ( a Phytophthora sojae effector) was added to a plasmid vector with GmNDR proteins to determine if binding occurred. Initial results did not indicate binding. Later, a fluorescence complementation assay was done and found the interaction of the two proteins occur along the cell periphery and on the nuclear membrane, suggesting a possible signaling role for GmNDR. However, more follow-up will be needed to verify this effect. Work was begun on a unrelated objective, to verify, based on previous research done in their lab, that salicylic acid participates in soybean defense to Phytophthora sojae. They have begun to clone soybean genes participating in salicylic acid biosynthesis and viral vectors targeting these genes for silencing have been constructed with results still forthcoming.
This project is still in the middle of generating results that foster the development of improved tools for disease resistance. Yet, some of the results thus far are useful for laying the groundwork for research and development in this area.