PreMiEr������������������s microbiome engineering framework will enable the development of a wide range of transformative technologies that solve societal challenges at the interface of health and the environment. However, the dissemination of these same technologies is not without risk as it relies on the responsible development and societal acceptance of microbiome engineering approaches. Thus, in this research core, we will consider the ethical, societal, and policy implications of PreMiEr������������������s evolving microbiome engineering discoveries. There have been national calls for cross-disciplinary and integrated work to better understand the social implications of microbiome science and engineering [1]. In parallel, there is increasing awareness that challenges at the nexus of human- and natural-world coupled systems cannot be solved by technology alone. Through the research and deliberative engagement approaches described below, PreMiEr research will embrace the concept of responsible research and innovation and its elements of anticipation, deliberation, reflexivity, and responsiveness [6]. Particular areas of inquiry will be on social equity of microbiome engineering, ownership and privacy of microbiome data and information, and ethical implications including informed consent, consumer and patient autonomy, beneficence, non-malfeasance, and procedural justice. Core B will also work with the natural scientists and engineers in other thrusts and cores to help identify and address policy and societal questions associated with risk governance and analysis, oversight of microbiome engineering, and equitable distribution of risks and benefits.

Success in establishment, growth vigor and biomass production for fiber crops heavily relies on symbiotic associations with mycorrhizal fungi. These beneficial associations improve nutrient acquisition, enhance crop performance especially under nutrient-limiting conditions, and increase resistance to abiotic and biotic stresses. However, the impact of symbiotic fungi on cotton K nutrition is largely understudied. The central objective of this proposal is to improve our understanding of the physiological and molecular bases for and the regulation of K transport mediated by arbuscular mycorrhizal fungi (AMF) in cotton as well as assessing the impact of AMF association in cotton���s tolerance to drought. We have recently shown that mycorrhizal fungi are able to allocate K to colonized plants and protect their host plant against drought in other model plants and crops (see preliminary data). Therefore, we hypothesize that the association between mycorrhizal fungi and cotton plants will enhance cotton productivity and sustainability, especially under low input and stressful conditions. In this project, we propose to (1) evaluate the impact of AMF on K acquisition and drought tolerance of multiple cotton cultivars commonly grown in North Carolina, (2) identify and characterized cotton genes and proteins that are directly involved in mycorrhiza-mediated K nutrition and/or drought tolerance on the most responsive cultivars, and (3) use rubidium as a proxy to track the transport of K from mycorrhizal fungi to colonized cotton plants under well-watered and water-limited conditions. This research is crucial to optimize nutrient uptake and biomass production for fiber crops under field conditions, to minimize the environmental impact of crop production with a reduction of our dependency on K fertilizers, and to harness soil beneficial fungi for cotton production. Objective 1: Investigate the impact of AMF on K nutrition and drought tolerance in ten cotton cultivars. We propose to investigate study the uptake of K from the soil by AMF and the K transfer from these fungi to the host plants using rubidium as analog tracer. We will also determine if this transfer is affected by soil water availability and salinity and map the supply of other nutrients (phosphorus and nitrogen) for the fungi and the host plant. Objective 2: Demonstrate that AMF can directly transport K to cotton seedlings and evaluate the host plant carbon investment. We propose to study the uptake of K from the soil by AMF and its transfer to three colonized cotton cultivars using rubidium as an analog tracer. We plan to determine if this transfer is affected by water availability. We will also track the carbon allocation from the host to the associated AMF depending on their ability to provide K to their host and under drought or well-watered conditions.

We will investigate the carryover effects of P fertilization on loblolly pine plantations and the effects on the soil microbial community.

We propose a quantum spin technology to image biochemical pathways in the rhizosphere with unprecedented chemical detail and sensitivity. Specifically, the proposed technology transfers the quantum entangled nuclear spin order of hydrogen gas, to metabolites, including nitrate, amino acids, nitrogen and pyruvate, to enable molecular imaging of their metabolic transformations without any penetration depth limitations such that molecular turnover and metabolism can be observed directly in soil.

Potassium (K) is an essential macronutrient for plants, and its availability strongly affects biomass production, tolerance to stress, and yield. 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. A better understanding of the strategies used by legumes to acquire K will be crucial to improving future crop productivity and environmental sustainability of crop production. The increasing demand for food and the development of alternative strategies for enhancing crop yields while reducing the use of chemical fertilizers represents a critical research priority. The overall of this project is to (1) confirm that AM fungi can transport K from the soil to the host legumes Medicago truncatula and soybean (2) understand how environmental factors (especially water limitation), nutrient availability, and carbon transport from the host to the AM fungus affects the symbiotic transport of K, and (3) identify and characterize the molecular mechanisms used by non-mycorrhizal and mycorrhizal legume plants in response to K deficiency.

More than a third of crop yields are currently lost due to abiotic and biotic stressors such as drought, pests, and disease. These stressors are expected to worsen in a warmer, drier future, resulting in crop yields further declining ~25%; however, breeding is only expected to rescue 7-15% of that loss [1]. The plant microbiome is a new avenue of plant management that may help fill this gap. All plants have fungi living inside their leaves (����������������foliar fungal endophytes���������������). This is an ancient and intimate relationship in which the fungi affect plant physiology, biotic and abiotic stress tolerance, and productivity. For example, some foliar fungi prevent or delay onset of major yield-limiting diseases caused by pathogens such as Fusarium head blight [2]. Foliar endophytes also reduce plant water loss by up to half and delay wilting by several weeks [3, 4]. Endophyte effects on plants occur via diverse genes and metabolites, including genes involved in stress responses and plant defense [5]. Genes and metabolites also predict how interactions in fungal consortia affect host stress responses, which is important for developing field inoculations [6]. Because newly emergent leaves lack fungi, endophytes are also an attractive target for manipulation (particularly compared to soils, where competition with the existing microbial community inhibits microbial additives). We propose to address the role of endophytic ����������������mycobiomes��������������� in stress tolerance of five North Carolina food, fiber, and fuel crops (corn, hemp, soybean, switchgrass, wheat), and to develop tools that can push this field beyond its current limits. Our major objectives (Fig. 1) are to: 1. Identify key microbiome scales to optimally manage endophytes 2. Determine fungal mechanisms via greenhouse tests, modeling, and genetic engineering 3. Build tools for field detection of endophytes 4. Understand the regulatory environment and engage diverse stakeholders Results of these objectives will allow us to make significant progress in both understanding the basic biology of plant-fungal interactions and managing those interactions in real-world settings. Our extension efforts will also bring these ideas to the broader community. Finally, we will also be well positioned to pursue several future research endeavors supported by federal granting agencies.

Arbuscular mycorrhiza (AM) are soil-borne fungi that form intimate symbiotic associations with the roots of most land plants. AM fungi act as extensions of the root system, increasing the root ����������������uptake area��������������� more than 1000-fold and considerably improving the plant's ability to acquire water and nutrients from the soil. AM fungi therefore substantially improve the host plant������������������s access to macronutrients including phosphorous (P), potassium (K) and nitrogen (N), and micronutrients. This proposal describes a project to understand the genetics controlling the association between corn and AM fungi. If successful, this will facilitate the increased used of AM fungi in corn cultivation and help reduce the expensive and ecologically-damaging use of fertilizers.

Potassium is an essential macronutrient for plants, and its availability strongly affects biomass production, tolerance to stress, and yield. Since only a small fraction of the soil potassium content is plant available, plants must develop efficient strategies for the uptake of potassium 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. AM fungi play an important role for plant and soil health. These beneficial fungi take up nutrients and water from the soil and deliver them to the plant. Although most studies have been done on the acquisition of phosphorus and nitrogen, we have recently demonstrated that AM fungi also have a positive impact on the potassium nutrition in legumes. A better understanding of the strategies used by legumes, and particularly soybean, to acquire potassium will be crucial to improving future crop productivity and environmental sustainability of crop production. The increasing demand for food and the development of alternative strategies for enhancing crop yields while reducing the use of chemical fertilizers represents a critical priority. We propose here to test if similar benefits provided by AM fungi can be observed in soybean in the field and in greenhouse, and to quantify the actual transport of K from the soil to mycorrhizal soybean roots in laboratory condition. The proposed project will allow us to determine whether AM fungi affect the yield, nutrient content, and productivity of soybean under different K regimes. Disseminating these results within the North Carolina Soybean Producers Association will help local soybean growers and producers to breed and select varieties that are able to interact more efficiently with mycorrhizal fungi, and to reduce the use of potash without affecting soybean growth and yield.