Center for Turfgrass Science

My research program focuses on sustainable cool-season turfgrass disease management, aiming to provide solutions for effective disease control while minimizing the unintended impact of disease control practices (i.e., fungicides).

To achieve this goal, my team strives to understand the short- and long-term effects of management practices on the pathobiome (disease-causing or -facilitating microbial community) and beneficial microbiome, leveraging multi-omics, digital PCR, and applied machine-learning techniques.

To facilitate real-world and practical impacts, my team also aims to translate biological findings and fundamental developments into accessible decision support tools for turfgrass managers through disease predictive models and pathogen quantification assays.

In addition, my team also directs a turfgrass disease control products efficacy evaluation program collaborating with industry partners. This program is among the largest of its kind in the U.S., testing 300-500 turfgrass synthetic and biological fungicide treatments against all major diseases each year.

All of these research and development activities directly fuel my outreach efforts to provide the latest science-based information and education to the turfgrass managers in New Jersey, the Northeast, and beyond.

I am a fungal biologist. In collaboration with other researchers in the Rutgers Center for Turfgrass Science, I have been working on microbiome associated with grasses. Microbiomes, the microbial community and their genomes in a system, play important roles in adaptation, stress tolerance and disease resistance of their associated plants. The next-generation sequencing technologies enable a holistic view of the microbial diversity compared to the culture-based methods that only capture a fraction of the total diversity. The long-term goal of our project is to describe the microbiomes associated with turfgrasses, understand the causality of microbiomes and the plant health/performance, and to translate this knowledge to develop new sustainable management strategies and other applications.

Similar to the gut microbiomes of human and other animals, microbial symbionts of plants also have important impacts on the health of plants in nature. For example, certain fungal endophytes help the grass hosts fight pathogens and insect pest and increase their heat and drought tolerance, while a number of bacterial and fungal species cause various diseases. When taking the microbiomes into consideration, we may be able to holistically answer many longstanding questions in turfgrass science.

Rhizophagy cycle endophytes

We are working to develop an understanding of rhizophagy cycle in turf grasses. The rhizophagy cycle is a new kind of symbiosis whereby plants obtain nutrients from bacteria that alternate between an intracellular/endophytic phase and a free-living soil phase. Bacteria acquire soil nutrients in the free-living soil phase; nutrients are extracted from bacteria oxidatively in the intracellular/endophytic phase. This process for nutrient extraction from microbes appears to be important in grasses and much of the experimental work involves use of turfgrass systems. There is some indication that beneficial endophytes in turf grasses may be those bacteria that are adapted to plants and participate in the rhizophagy cycle, delivering nutrients from soils; endophytes that are not beneficial in turf grasses may be those bacteria that are not adapted for the rhizophagy symbiosis and do not carry nutrients into plants.

Bioherbicidal microbes

In collaboration with Dr. Matt Elmore we are examining ways to control weeds by inhibiting the symbiosis of the weed with endophytic microbes. We have identified microbial endophytes that may be used to promote turf grass growth (and other crops), but that will simultaneously inhibit competitor weed growth. Our goal is to use endophytes to replace herbicides in turf grass systems.

The major focus of Dr. Tumer’s laboratory is to understand the ribosome interactions and the mechanism of toxicity of ribosome inactivating proteins (RIPs) and trichothecene mycotoxins.

Ricin is a plant toxin used in targeted killing of cancer cells and is a concern for bioterrorism. The related Shiga toxins (Stxs) produced by Shigella and E. coli O157:H7 (STEC) cause food-borne outbreaks and are major concerns for public health. Currently, there are no vaccines or therapeutics to protect against ricin or STEC. Dr. Tumer’s research played a central role in defining the cellular targets of RIPs and trichothecene mycotoxins. Their studies established a new paradigm for the mechanism of depurination of the sarcin/ricin loop and identified toxin/ribosome interactions as a new target for inhibitor discovery. Dr. Tumer’s lab developed fragment-based lead discovery (FBLD) using surface plasmon resonance (SPR) to discover small molecule inhibitors of ricin and Stxs.

Dr. Tumer studies the mode of action of trichothecene mycotoxins produced by Fusarium graminearum, which causes Fusarium head blight (FHB), a devastating disease affecting cereal crops. There is no effective resistance to FHB in cereals. Using chemical genomics approaches they identified mitochondria as a target of trichothecene mycotoxins and showed that trichothecene-induced oxidative stress plays a major role in trichothecene toxicity. They screened activation tagged Arabidopsis lines for resistance to trichothecenes and identified a novel lipid transfer protein (LTP) that confers resistance to trichothecenes and FHB in wheat.

Brad Park performs turfgrass research with an emphasis on sports field management as part of Dr. James Murphy’s Turfgrass Management Research and Extension project. We perform traffic stress tolerance research on cool-season turfgrass commonly established on sports field in New Jersey and throughout the Northeast and Mid-Atlantic; trials include those sponsored by the National Turfgrass Evaluation Program with additional support provided by the Rutgers Center for Turfgrass Science.

We are actively involved in research projects concerning low-input turfgrasses for public grounds, home lawns, and highway roadsides. Brad maintains a New Jersey Dept. Environmental Protection-issued pesticide license and is certified in CORE, 3B (Turf) 10 (Demonstration & Research), and 6B (Right-of-Way) and performs numerous cooperator-funded field studies on an annual basis. Brad annually delivers talks on integrated pest management in sports fields, with an emphasis on cultural practices and turfgrass species and variety selection and frequently addresses practitioner audiences at the state, regional, and national level.

My research interests include the study of mechanisms that control programmed cell death and stress tolerance in plants, the regulation of global gene expression via chromatin organization, and more recently, the establishment and promotion of an aquatic agriculture platform with duckweed for sustainable biomass production.

Programmed Cell Death and Plant Stress Tolerance

Controlled cellular suicide is used by plants, much like in animals, to remove unwanted or damaged cells during development and disease, as well as during times of environmental stresses. My work over the past 20 years focus on studying two highly conserved types of proteins that control the activation of cellular suicide in plants, a protease family called metacaspases that is involved in regulating activation of plant cell death and a cell death repressor called BI-1 (Bax Inhibitor-1) that suppresses cell death in both plants and animals. Recent work with collaborators in the University of Sao Paulo has demonstrated that overexpression of plant BI-1 orthologs in sugarcane can improve drought tolerance, demonstrating that modulation of cell death can help create important traits for crops that have better resilience to severe environmental stresses.

Epigenetics and Chromatin Organization

Regulating the output from the genome without a change in DNA sequence (i.e. epigenetics) is intimately linked to dynamic changes in how chromatin is organized. My lab has carried out systematic studies to profile global histone modifications in the model plant Arabidopsis thaliana and to devise new strategies to combine and correlate multiple datasets in order to identify key combinations of genomic features and functional output. This bioinformatic strategy has enabled the identification of gene sets for development functions that may be primed for drought activation in the moss Physcomitrella patens. More recently, in collaboration with other researchers, we are focusing our work on demonstrating the role of epigenetic control in development of specialized cell types on the surface of plant leaves called guard cells. These special cells made up the stomates on leaf surfaces and are key to regulating gas exchange to facilitate carbon fixation and temperature control. Using the technique called INTACT, we are currently isolating chromatin from various progenitor stages of these specialized cells to characterize their chromatin marks and pinpoint the regions in the chromatin that are systematically modified during the genesis of the mature guard cells. The results from this work may provide a clear example of how predictable changes in chromatin organization may underlie a specific developmental pathway.

Establishing Duckweed as a Novel Microcrop

Duckweed, a family of aquatic moncots that are related to grasses, is the fastest growing flowering plants in the world. Some duckweed strains have been shown to have have protein and/or starch and can be used as animal feed or to produce biofuel. My lab has been working over the past decade to help realize the great potential of duckweed. Recently, I have led a team of researchers to complete a high fidelity reference genome for the Greater Duckweed Spirodela ployrhiza using a combination of cutting-edge DNA sequencing technologies. His lab has also successfully demonstrated a novel approach to generate high-resolution genotyping tools that can distinguish closely related duckweed strains. My work in this area emphasizes the use of evolutionary relationships and genomics to identify candidate genes for critical metabolic switches in metabolism as well as creating new technologies for duckweed related applications. Recent innovations include the conception and construction of a scalable duckweed production module (DPM) that should facilitate domestication of this aquatic plant family as a novel crop.