Crop and Soil Sciences
Non Technical Summary
Potassium (K) is an essential macronutrient for plants. Since only a small fraction of the soil K content is plant available, plants must develop efficient strategies for its uptake from the soil. The most important strategy used by plants to acquire nutrients is the arbuscular mycorrhizal (AM) symbiosis, a mutualistic association between the majority of land plants and ubiquitous soil fungi. We have recently demonstrated that AM fungi can also have a positive impact on legume K nutrition, but the physiological and molecular mechanisms underpinning this symbiotic exchange are only poorly understood.The overall of this project is to (1) demonstrate the factors that affect K translocation through AM fungal hyphae, (2) characterize the significance of fungal K transport for the resource exchange processes between plants and AM fungi in laboratory and field experiments, (3) identify plant genes that are directly involved in mycorrhizal-dependent K nutrition, and (4) functionally characterize key candidate genes that control K flux from the soil to legume roots through the AM symbiosis.As land grant universities, North Carolina State University and South Dakota State University apply their research to benefit the economic, intellectual, and social endeavors of citizens. Our project will provide fundamental insights into the molecular mechanisms governing the symbiotic acquisition of K, and this is critical to developing new strategies to reduce the dependence on energy-intensive chemical fertilizers. Our project addresses the "Agricultural Microbiomes" area priority by investigating how the microbio-components of agricultural systems can be managed to improve crop productivity and resilience to low nutrient availability.
Animal Health Component
Research Effort Categories
Goals / Objectives
Demonstrate the direct transport of potassium from the soil to M. truncatula and soybean plants via AM fungi, and test the effect of environmental factors (drought, salinity) on this transport.Assess the carbon investment into fungal potassium transport and the significance of fungal potassium transport for biological nitrogen fixation of legumes.Identify plant genes that control the potassium uptake in mycorrhizal and non-mycorrhizal M. truncatula and soybean plants using gene expression networks and reverse genetics.Examine the impact of AM communities on potassium uptake of soybeans under field conditions.
- Study the uptake of K from the soil by the mycorrhizal fungus R.irregularis and the K transfer from the fungus to the host using Rb as K tracer. We will also determine if this transfer is affected by environmental changes (water availability and salinity), and the supply of other nutrients for the plant or the fungus.- Evaluate how the carbon supply from M. truncatula and soybean plants affects fungal K transport, and whether fungal K transport plays a significant role for the biological nitrogen fixation of root nodules.- Identify regulators of K nutrition in colonized or non-colonized plants of the model legume soybean using RNA-Seq and co-expression network studies comparable to the one we performed in M. truncatula, and (2) test the role of the predicted regulators in both M. truncatula and soybean plants using a reverse genetic approach.- Directly translate our findings to the field, and will test the applicability of our results to field grown soybean production systems with the goal to develop recommendations for growers and extension personnel.