Characterization of symbiosis genes in maize

Symbiotic relationships between plants and microbes are essential to plant productivity, but are complex and depend on many plant genes for normal function. A common symbiosis between plants and arbuscular mycorrhizal fungi (AMF) is required for normal nutrient uptake in many land plants, including important crop species such as maize. Previous work suggests that nodulin-protein encoding gene relatives may affect mycorrhizal interactions. Candidate nodulin-protein encoding gene relatives were selected from the maize genome. For each candidate gene, seed stock was ordered that had a transposon mutation expected to knock-out function of the gene. Seed stocks were grown in AMF-inoculated soil to determine if the candidate gene knock out affected AMF symbiosis and plants were genotyped to determine if one or both copies of the gene were mutated. It is expected that the mutant plants will have a reduced amount of AMF-root colonization as well as reduced height and stem width. Next, two to three stocks with mutations of significant effect will be self- fertilized. These seeds will be grown to measure links between genotype, gene expression, and phenotypes. Determination and characterization of plant genes involved in symbiosis highlight gene targets for breeding efforts to reduce fertilizer dependence and the environmental impacts of crop production.