Location: Corn Insects and Crop Genetics Research
2023 Annual Report
Objectives
Objective 1. Conduct research to identify and characterize novel genes, markers, and molecular networks in the NPGS soybean collection that contribute to increased abiotic stress tolerance, and work with other researchers to develop soybeans with improved yield through tolerance to traits such as iron and phosphate deficiency.
Sub-Objective 1A. Conduct comprehensive phenotyping of a soybean iron stress panel.
Sub-Objective 1B: Conduct whole genome expression analyses of the soybean iron stress panel.
Sub-Objective 1C: Build gene regulatory network (GRN) for iron stress.
Sub-Objective 1D: Characterize iron stress regulators using VIGS and genome editing.
Sub-Objective 1E: Couple grafting with RNA-seq to study iron stress root and shoot signaling.
Objective 2: Conduct research to identify and characterize novel genes, markers, and molecular networks in the NPGS soybean collection that confer or enhance disease resistance, and work with other researchers to use the information to develop soybeans with improved resistance or tolerance to diseases such as Asian soybean rust, Phytophthora rot, and brown stem rot.
Sub-Objective 2A: Conduct whole genome expression analyses of a Rpp (Resistance to P. pachyrhizi) panel.
Sub-Objective 2B: Conduct whole genome expression analyses of candidate effector overexpression transgenic lines.
Sub-Objective 2C: Build gene regulatory network (GRN) for resistance to P. pachyrhizi.
Sub-Objective 2D: Characterize P. pachyrhizi defense and immunity regulators using VIGS and genome editing.
Approach
Improving crop yields and mitigating losses to biotic and abiotic stress is critical to global food security. While crop production must sustain population growth, we must minimize our dependence on supplemental nutrients and reduce the impact of pathogens on crop quantity and quality. The overarching goal of this project is to develop gene regulatory networks for soybean abiotic and biotic stress responses, using our long history of research in iron deficiency stress and Phakopsora pachyrhizi disease resistance as models. By leveraging the soybean germplasm collection, extensive phenotyping, gene expression and protein interaction studies, we will identify the major signaling genes regulating these networks. Virus induced gene silencing and genome editing will be used to characterize their function and the networks they control. Successful completion of the objectives will result in validated genes and markers for improving soybean stress responses. Results will be added to publicly available databases, for use by the legume research community. The knowledge generated will accelerate breeding programs and enable the engineering of new and improved traits for soybean.
Progress Report
In support of Sub-objective 1.A: Conduct comprehensive phenotyping of a soybean iron stress panel.
Characterization of a soybean iron stress panel. Iron deficiency chlorosis (IDC) is a global crop production problem, significantly impacting yield. While various genetic approaches have been used to identify genes involved in iron stress tolerance from model species, few studies have focused on agronomically important crop species or within multiple lines within a crop. In collaboration with scientists at Iowa State University, we previously identified 18 soybean genotypes with a range of iron stress tolerances. Seeds from these lines were requested from the USDA-ARS Germplasm Resources Information Network (GRIN). In Spring of 2023, seed were planted in Ames, Iowa, to provide sufficient seed quantity for conducting comprehensive phenotyping, whole genome expression analyses, virus induced gene silencing and genome editing.
In support of Sub-objective 2.A: Conduct whole genome expression analyses of Rpp (Resistance to Phakopsora pachyrhizi) panel.
Whole genome expression analyses of the Rpp (Resistance to Phakopsora pachyrhizi) panel. Soybean rust, caused by the fungus Phakopsora pachyrhizi, is an economically important disease that negatively impacts soybean production throughout the world. While most soybean germplasm is susceptible, seven genetic regions have been identified that provide resistance to P. pachyrhizi (Rpp1 to Rpp7). For each Rpp gene, we have requested seed from two nearly identical soybean lines, one resistant and one susceptible to P. pachyrhizi. Seed will be increased in our green house in the Fall/Winter of 2023 to provide sufficient seed quantity for conducting comprehensive phenotyping, whole genome expression analyses, virus induced gene silencing and genome editing
Accomplishments
