2015
Development of novel soybean germplasm for improving soybean for SDS resistance
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Contributor/Checkoff:
Iowa Soybean Association
Category:
Sustainable Production
Keywords:
GeneticsGenomics
Parent Project:
Development of novel soybean germ plasm for improving soybean for SDS resistance
Lead Principal Investigator:
Madan Bhattacharyya, Iowa State University
Co-Principal Investigators:
Silvia Cianzio, Iowa State University
Project Code:
Contributing Organization (Checkoff):
Iowa Soybean Association
(n/a)
Institution Funded:
Iowa State University
(n/a)
Brief Project Summary:

Soybean sudden death syndrome is a major threat to soybean production. It is caused by a fungal pathogen, Fusarium virguliforme. The goal of this project is to express soybean and F. virguliforme genes in transgenic soybean plants, and then determine if expression of any of these genes enhances resistance to the SDS pathogen. The genes will be selected based on prior information that most likely these genes play major roles in disease resistance. Then, work will generate transgenic soybean lines with polyamine oxidase for enhancing SDS resistance and introgress the genes created into elite soybean lines.

Key Benefactors:
farmers, agronomists, Extension agents, soybean breeders, seed companies

Information And Results
Final Project Results

1. Progenies of the transgenic soybean lines carrying selected fusion genes from the four classes of soybean genes and one F. virguliforme gene will be evaluated for responses to F. virguliforme infection.
Progress: Last year we harvested seeds of several transgenic soybean lines generated from transformation of soybean with 11 fusion genes. The fusion genes were developed from four soybean genes that are suppressed by F. virguliforme infection and three promoters that up-regulate expression of genes during infection. We have observed that when we forced the expression of soybean genes, GmSAMT1, GmARP1, and GmDS1 during F. virguliforme infection by altering their promoters, we were able to enhance SDS resistance among the transgenic soybean lines.
We observed that transgenic soybean plants with induced expression of GmDS1 showed a broad-spectrum resistance not only against the fungal pathogen, F. virguliforme, but also against the oomycete pathogen, Phytophthora sojae, soybean cyst nematodes (SCN), soybean aphids and spider mites. We also observed that a F. virguliforme gene, FvPO1, enhances foliar as well as root resistance to the SDS pathogen in transgenic soybean plants.

2. Suitable transgenic lines showing enhanced SDS resistance will be crossed to elite soybean lines.
Progress: This summer 2015, we grew R1 and some R¬1 plants in the field for seed increase as well to evaluate for SDS resistance. We are now doing molecular analysis for the selection of homozygous lines that will be crossed to an elite soybean line.

3. We expect that the first backcross generation for introgression of the desirable genes for SDS resistance into elite lines will be generated and selected by conducting molecular analyses.
Progress: We received an APHIS permit to grow transgenic lines in the field for evaluation of SDS resistance. Fifty-four transgenic lines carrying four soybean genes and one F. virguliforme FvPO1 gene were brought to the field for evaluation of SDS resistance. These include 12 lines carrying GmARP1, 17 lines with GmSAMT1, 18 lines carrying GmDS1, four with GmDS1, and three for FvPO1. Each transgenic line was grown in two replications and F. virguliforme inoculum was added to the soil during sowing. Results are summarized below.
- For GmSAMT1, from the 12 lines evaluated, 11 showed more than 70% of plants resistant to F. virguliforme and one line had only 40% resistant plant.
- For GmARP1, six lines were evaluated. All six lines shown to carry more than 70 % SDS resistant plants.
- For GmDS1, 13 lines were evaluated. Of the 13 lines, 11 lines shown to contain more than 55% of resistant plants.
- For GmSEO1, four lines were evaluated; three lines shown to carry >64% resistant plants and one line only 20% resistant plants.
We are now conducting molecular analysis of these resistant and susceptible plants to correlate the copy number of the transgenes to the resistant phenotype. We are behind this objective, and crosses will be possible to make only after the desirable transgenic plants are identified.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.