About

Kevin Garcia is an Associate Professor in the Department of Crop and Soil Sciences at NC State University. His research focuses on deciphering the molecular basis of bi-directional nutrient fluxes between plant roots and soil microbes, with particular emphasis on arbuscular mycorrhizal and ectomycorrhizal associations. His work explores how mycorrhizal fungi improve plant nutrition and aims to utilize these natural symbioses to reduce fertilizer use in agricultural and agroforestry practices. Dr. Garcia's research employs physiological, biochemical, molecular, genetic, and transcriptomic approaches to identify the molecular players involved in nutrient allocation within these plant-microbe associations. His contributions aim to harness plant-microbe interactions to enhance nutrient use efficiency and tolerance to environmental changes in agroecosystems.

Research topics

• Biology
• Botany
• Cell biology
• Genetics
• Biochemistry
• Chemistry
• Ecology

Selected publications

• Nodulation Is Maintained and Salinity Tolerance Enhanced in Two Soybean Cultivars Inoculated With <scp> <i>Sinorhizobium fredii</i> </scp> Under Brackish Water

  Physiologia Plantarum · 2025-09-01

  articleOpen accessSenior authorCorresponding

  Salinity is an increasing threat to agriculture, particularly in coastal regions affected by seawater intrusion and sea-level rise. This study evaluated the halotolerance and symbiotic potential of Sinorhizobium fredii USDA 208 in two soybean cultivars (includer and excluder) under three salinity levels-low (freshwater), moderate (brackish water), and high (seawater). The results demonstrated that S. fredii not only tolerates but also exhibits enhanced growth under moderate salinity. Nodulation was successfully established when salinity and inoculation occurred simultaneously. Nodulation was also maintained when salinity occurred after the inoculation, particularly in fresh and brackish water. Root development declined with increasing salinity, but the includer cultivar showed better root system architecture plasticity in brackish water, while the excluder cultivar exhibited higher shoot and root biomass across salinity levels. Bacterial inoculation improved shoot phosphorus uptake, the potassium: sodium ratio, and carotenoid retention, particularly in the includer cultivar, suggesting an enhanced physiological tolerance to moderate salinity. Inoculation also resulted in higher shoot nitrogen and maintained pigment content. Using a seawater recipe provides a better understanding of salinity than traditional NaCl-based studies and highlights the role of S. fredii USDA 208 in supporting soybean performance when salts accumulate in coastal agricultural soils.

  PublisherOA PDFDOI

• Mutualistic Relationships Between Roots and Soil Microbes Facilitate Plant Potassium Acquisition

  Progress in botany · 2025-01-01 · 2 citations

  book-chapterSenior author
  PublisherDOI

• The external potassium availability determines the effect of the arbuscular mycorrhizal fungus Rhizophagus irregularis on salinity tolerance in soybeans

  Symbiosis · 2025-06-01 · 3 citations

  articleOpen accessSenior author

  Abstract Arbuscular mycorrhizal (AM) fungi improve water and nutrient acquisition of most land plants. Additionally, they can help plants to alleviate abiotic stresses, such as salinity which causes a major threat for many crop species. Potassium (K + ) plays a major role in plant tolerance to salinity, and we recently demonstrated, by using rubidium (Rb + ) as a proxy, that AM fungi can directly transfer K + to their host plant. Here, we first investigated the impact of K + availability on soybean root development upon salinity. Then, using two-compartment systems, we also inoculated soybean plants with the AM fungus Rhizophagus irregularis , grew them in various K + and sodium (Na + ) regimes, and used Rb + to track K + movements. Root development parameters, biomass, colonization rate, and nutrient concentrations were assessed in AM and non-mycorrhizal plants. Our results show that soybean root development was significantly affected by NaCl treatments, rather than K + availability. Additionally, although the AM symbiosis was drastically reduced by high salinity, it improved K + concentrations and prevented Na + accumulation in inoculated plants, mainly under limiting K + conditions. Rb + transport was observed only when the plants were in demand for K + , but was inhibited by high salinity. Finally, we also show that the addition of NaCl slightly influences the availability of K + and Rb + . This report shows the combined impact of K + availability and AM symbiosis on soybean tolerance to salinity and discusses the limitations of using Rb + as a proxy for K + upon increasing salinity conditions.

  PublisherOA PDFDOI

• Endomycorrhizal inoculant evaluation on soybean in North Carolina under varying potassium levels

  Agronomy Journal · 2025-09-01

  articleSenior author

  Abstract Potassium (K + ) is a key macronutrient for plant growth. While arbuscular mycorrhizal (AM) fungi have been shown to enhance K + uptake in model legumes like barrel medic ( Medicago truncatula ), their effect on crop legumes such as soybean [ Glycine max (L.) Merr.] is not well documented. A 2‐year field study across three North Carolina regions assessed the impact of AM inoculation on soybean growth, nutrient uptake, yield, and seed quality. Trials targeted soils low in phosphorus and K + , using K + chloride to establish high (67 kg ha −1 ) and low (0 kg ha −1 ) K + environments. Three commercially available soybean cultivars (maturity groups IV, V, and VI) were either inoculated with AM fungi or left untreated. Measurements at 10 and 16 weeks post‐planting included chlorophyll content estimation, shoot biomass, and tissue nutrient concentrations. Results indicated that environmental conditions and cultivar maturity group had the strongest influence on biomass, K + uptake, yield, protein, and oil content. AM inoculation had limited impact across treatments. These findings, consistent with previous studies, suggest that AM inoculation offers minimal practical benefit for soybean K + nutrition under field conditions in North Carolina. Growers should critically evaluate product claims and use caution when adopting AM inoculants expecting significant yield improvements.

  PublisherDOI

• Establishment of a rapid split-root assay in hydroponic conditions for eight upland cotton varieties

  MethodsX · 2025-11-09

  articleOpen accessSenior authorCorresponding

  L.) is a major crop in the United States. Understanding how cotton roots develop and respond to abiotic and biotic factors is crucial for improving nutrient acquisition, enhancing crop resilience under stress, and optimizing overall crop production. Split-root techniques have been developed for numerous plant species, providing a controlled framework for monitoring root development, and investigating systemic and local plant responses to various environmental factors. However, a standardized cotton-specific protocol optimized for laboratory studies has yet to be established. This protocol facilitates the rapid establishment of split-root systems in eight upland cotton varieties within four weeks after germination. This is accomplished by cutting the primary root and immediately transplanting the seedlings into hydroponic conditions to promote lateral root growth, after which the root system can be divided equally into separate compartments. Once established, each compartment can be subjected to different, independent treatments. This method was validated across all eight varieties by quantifying the difference in root dry weight between the two halves of each plant's root system and analyzing those differences across varieties. Statistical analysis was performed and Kruskal-Wallis and Wilcoxon signed-rant tests confirmed no significant difference between the roots of the two sides for any cultivar, thus confirming this method's reliability.-We developed a standardized split-root protocol tailored for upland cotton using hydroponics.-This protocol was performed on eight varieties within four weeks after germination.-We validated the method by comparing root biomass distribution between compartments to confirm reliability.

  PublisherDOI

• X-ray fluorescence and XANES spectroscopy revealed diverse potassium chemistries and colocalization with phosphorus in the ectomycorrhizal fungus Paxillus ammoniavirescens

  Fungal Biology · 2024-08-08 · 4 citations

  articleSenior authorCorresponding
  PublisherDOI

• Pinus taeda carryover phosphorus availability on the lower Atlantic Coastal Plain

  Forest Ecology and Management · 2024-01-31 · 1 citations

  article
  PublisherDOI

• Using microdialysis to assess soil diffusive P and translocated sap flow P concentrations in Southern Pinus taeda plantations

  Plant and Soil · 2024-01-05 · 1 citations

  articleSenior author
  PublisherDOI

• Fungal biomass and ectomycorrhizal community assessment of phosphorus responsive Pinus taeda plantations

  Frontiers in Fungal Biology · 2024-05-28

  articleOpen access

  Ectomycorrhizal fungi and non-ectomycorrhizal fungi are responsive to changes in environmental and nutrient availabilities. Although many species of ectomycorrhizas are known to enhance the uptake of phosphorus and other nutrients for Pinus taeda , it is not understood how to optimize these communities to have tangible effects on plantation silviculture and P use efficiency. The first step of this process is the identification of native fungi present in the system that are associated with P. taeda and influence P uptake efficiency. We used sand-filled mesh bags baited with finely ground apatite to sample ectomycorrhizal and non-ectomycorrhizal fungi associated with the rhizosphere of P-responsive P. taeda under several field conditions. Mesh bags were assessed for biomass accumulation over three years using a single three-month burial period pre-harvest and three six-month burial periods post-planting. Amplicon sequencing assessed ectomycorrhizal and non-ectomycorrhizal communities between phosphorus treatments, sites, mesh bags, and the rhizosphere of actively growing P. taeda in the field. We found biomass accumulation within the mesh bags was inversely related to increasing phosphorus fertilization (carryover) rates from pre-harvest to post-planting. Up to 25% increases in total biomass within the bags were observed for bags baited with P. Taxonomic richness was highest in Alfisol soils treated with phosphorus from the previous rotation and lowest in the Spodosol regardless of phosphorus treatment.

  PublisherOA PDFDOI

• The ectomycorrhizal fungus <i>Paxillus ammoniavirescens</i> influences the effects of salinity on loblolly pine in response to potassium availability

  Environmental Microbiology · 2024-03-01 · 8 citations

  articleOpen accessSenior authorCorresponding

  Abstract Salinity is an increasing problem in coastal areas affected by saltwater intrusion, with deleterious effects on tree health and forest growth. Ectomycorrhizal (ECM) fungi may improve the salinity tolerance of host trees, but the impact of external potassium (K + ) availability on these effects is still unclear. Here, we performed several experiments with the ECM fungus Paxillus ammoniavirescens and loblolly pine ( Pinus taeda L.) in axenic and symbiotic conditions at limited or sufficient K + and increasing sodium (Na + ) concentrations. Growth rate, biomass, nutrient content, and K + transporter expression levels were recorded for the fungus, and the colonization rate, root development parameters, biomass, and shoot nutrient accumulation were determined for mycorrhizal and non‐mycorrhizal plants. P. ammoniavirescens was tolerant to high salinity, although growth and nutrient concentrations varied with K + availability and increasing Na + exposure. While loblolly pine root growth and development decreased with increasing salinity, ECM colonization was unaffected by pine response to salinity. The mycorrhizal influence on loblolly pine salinity response was strongly dependent on external K + availability. This study reveals that P. ammoniavirescens can reduce Na + accumulation of salt‐exposed loblolly pine, but this effect depends on external K + availability.

  PublisherOA PDFDOI

Frequent coauthors

• Sabine Zimmermann

  77 shared

• Geneviève Conéjéro

  Université de Montpellier

  52 shared

• Adeline Becquer

  Ecologie fonctionnelle & biogéochimie des sols & des agro-systèmes

  41 shared

• Amandine Delteil

  Laboratoire des Symbioses Tropicales et Méditerranéennes

  41 shared

• Claude Plassard

  Centre de Coopération Internationale en Recherche Agronomique pour le Développement

  38 shared

• Hervé Sentenac

  Centre National de la Recherche Scientifique

  36 shared

• Carmen Guerrero‐Galán

  25 shared

• Gabriella Houdinet

  North Carolina State University

  25 shared

Education

• Ph.D. in Integrative Plant Biology, B&PMP

  Université de Montpellier

  2013

• M.S. in Functional Biology of Plants

  Université de Montpellier

  2010

• B.S. in Biology of Organisms

  Université Jean Monnet Saint-Etienne

  2008