On March 17, 2025, Bill Errickson successfully defended his PhD dissertation, Physiological, Metabolic, and Molecular Regulation of Ethylene-Suppressing Rhizobacteria to Improve Turfgrass Tolerance to Drought Stress, at Rutgers University. Under the mentorship of Professor Bingru Huang, Bill’s research explored the potential of plant growth-promoting rhizobacteria (PGPR) to mitigate drought stress in cool-season turfgrass—a pressing issue for both sports turf management and water conservation efforts.
Besides Bingru Huang, Bill’s PhD committee included Ning Zhang (Rutgers), Jim White (Rutgers), and Yan Xu (Ramapo). Ning Zhang and Jim White played an important role in shaping Bill’s research, and the Paraburkholderia aspalathi endophytic bacteria used in his study were sourced from a collection preserved in Ning Zhang’s lab at Rutgers.
Bringing Extensive Experience to Turfgrass Research
Bill’s academic and professional journey reflects a deep commitment to sustainable agriculture and plant stress physiology. Before pursuing his PhD, he earned:
· M.S. in Natural Resources: Soil Science from the University of New Hampshire (2007)
· B.S. in Biology from Stockton University (2004)
Beyond academia, Bill has built an extensive career in agricultural extension and applied research. As County Agent III / Assistant Professor with Rutgers Cooperative Extension, he works closely with growers, landscape professionals, and turf managers to develop science-driven best practices. He has secured over $4.2 million in externally funded research grants, with significant contributions to projects on turfgrass water conservation, sustainable nursery practices, and stress-mitigating microbial inoculants.
He has also co-authored peer-reviewed journal articles, book chapters, and extension fact sheets on topics including plant-microbe interactions, soil health, and native plant propagation. His pending U.S. patent application (Huang, Zhang, Errickson, 2021) reflects his contributions to developing microbial-based strategies for improving plant stress tolerance. Bill’s impressive CV is appended at the bottom of this post.
Tackling Turfgrass Drought Stress with Microbes
Drought stress is a major challenge in turfgrass maintenance, leading to chlorosis, reduced growth, and canopy thinning. Bill’s research focused on Paraburkholderia aspalathi strains, particularly WSF23 and WSF14, which produce the enzyme ACC deaminase (ACCd). This enzyme breaks down 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor to ethylene—a phytohormone that exacerbates drought-induced senescence. By reducing ethylene levels, these bacteria help turfgrass maintain growth and improve recovery post-drought.
Key Findings from Controlled Studies
In greenhouse experiments with creeping bentgrass (Agrostis stolonifera cv. Penncross), inoculation with P. aspalathi led to several physiological and metabolic benefits, including:
· Higher turf quality and canopy density during drought stress and re-watering.
· Increased root viability and biomass, which enhanced water uptake.
· Enhanced carbohydrate accumulation (glucose, fructose, sucrose) in crown tissues, supporting energy reserves.
· Suppression of ethylene production, reducing stress-induced damage.
· Modulation of phytohormones, with increased cytokinins (promoting growth) and reduced abscisic acid (limiting drought stress responses).
Metabolomic and Transcriptomic Insights
Bill’s research extended beyond physiological assessments to analyze changes at the molecular level. Metabolomic studies revealed that ACCd bacterial inoculation boosted amino acids (proline, asparagine) and antioxidants (riboflavin), enhancing osmotic regulation and oxidative stress defense. Gene expression analysis showed upregulation of stress-responsive genes related to energy metabolism and root growth, reinforcing the plant’s ability to withstand drought conditions.
Field Trials: Translating Lab Success to Real-World Turfgrass Management
To evaluate practical applications, Bill conducted two years of field trials on fairway creeping bentgrass (Agrostis stolonifera cv. L-93) under deficit irrigation. His results confirmed that:
· A soil drench inoculation method was significantly more effective than foliar spray.
· Higher bacterial concentrations (1.5x recommended dose) improved turf quality and canopy density.
· A combination of WSF23 and WSF14 strains provided the best overall performance, suggesting a synergistic effect.
Implications for Turfgrass Management and Beyond
Bill’s work has major implications for sustainable turf management. With increasing concerns about water use in landscaping, sports fields, and golf courses, microbial inoculants like P. aspalathi could offer a natural, effective way to improve drought resilience while reducing chemical inputs. His findings also contribute to broader research on plant-microbe interactions, opening new avenues for enhancing stress tolerance in other crops and ecosystems.
Dr. Bill Errickson’s research represents a significant step forward in understanding and applying microbial solutions for plant stress management. His work will undoubtedly influence future studies in plant-microbe interactions and sustainable turfgrass management. he plans to continue in his role as an Extension Agent for Rutgers Cooperative Extension for Monmouth County in the Department of Agriculture and Natural Resources. He started the position in Fall 2019 while he was still a PhD student and finished his thesis work while working full-time.
Congratulations, Bill, on an outstanding PhD defense!
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