Source: PENNSYLVANIA STATE UNIVERSITY submitted to NRP
DEVELOPING DISEASE SUPPRESSIVE PHYLLOSPHERE MICROBIOMES THROUGH APPLIED ECOLOGY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
Reporting Frequency
Annual
Accession No.
1030320
Grant No.
2023-67013-39457
Cumulative Award Amt.
$850,000.00
Proposal No.
2022-11090
Multistate No.
(N/A)
Project Start Date
May 1, 2023
Project End Date
Apr 30, 2027
Grant Year
2023
Program Code
[A1402]- Agricultural Microbiomes in Plant Systems and Natural Resources
Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505
Performing Department
(N/A)
Non Technical Summary
Effectively managing plant microbial diseases continues to be an important priority worldwide toensure an adequate supply of safe and nutritious food. Historically, chemical controls, such asantibiotics or fixed copper compounds, have been heavily relied upon to manage foliar bacterialdiseases. However, sustained use of a chemical controls has resulted in the emergence of resistanceto multiple chemical agents in pathogen population, thus negating their effectiveness. Biologicalcontrols, where a live organism or product derived from a live organism is applied, have been usedas alternatives to chemical antimicrobials, however, biocontrols typically exhibit highlyinconsistent results from region to region and between growing seasons, which has limited theirpotential as reliable disease management options. The proposed research will investigate thepotential for developing a whole microbial community-based approach to manage crop foliardiseases. This research seeks to translate our understanding of naturally occurring suppressive soils,which are able to reduce the impacts of soil-borne pathogens, into the phyllosphere environment.Preliminary data from our group suggests this is possible. Specifically, this research will test 1)whether suppressive communities can be developed for two distinct bacterial pathogens that infecttomato foliar tissues tomato, 2) how ecological conditions affect the emergence and strength ofthese communities, 3) how specific the suppression is for each community, and 4) which specificmicrobial taxa contribute to disease suppression. This research has the potential to improve ourability to control foliar plant diseases using an environmentally sustainable approach.
Animal Health Component
25%
Research Effort Categories
Basic
75%
Applied
25%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2151460107050%
2161460110050%
Goals / Objectives
Aim 1: Determine if suppressive communities can be developed for bacterial speck and bacterial spot of tomato, as well as how initial community diversity affects suppression dynamics.Aim 2: Assess how disease suppressive communities interact with common agricultural practices, such as application of chemical pesticides.Aim 3: Identify microbial taxa enriched within suppressive communities and assess their ability to recapitulate disease suppression.
Project Methods
Microbial community acquisition, inoculation, passaging, and assessment of community effect on disease outcome will be performed as previously described (Ehau-Taumaunu and Hockett, Phytobiomes Journal, 2022). Microbial community taxanomic and organismal diversity will be modified by altering the number of independent sources for the initial community and size exclusion filtration, respectively. The effect of chemical pesticide application will be assessed by applying each pesticide according to the manufacturer specifications. Pathogen antagonist populations will be identified using both standard amplicon and metagenomic sequencing and analysis approaches. Once identified, standard and high throughput culturing techniques will be used to isolate fungi, bacteria, and bacteriophage that will be tested using standard techniques for disease suppression against the target pathogens. Outputs from this work will be evaluated for success through: publication of primary and reveiw scientific papers, development of multiple (>2) passaged disease suppressive communities that are storable and recoverable, and development of multiple (>2) disease suppressive synthetic communities that are derived from the passaged communities, but which can be precisely formulated.

Progress 05/01/23 to 04/30/24

Outputs
Target Audience:Audiences reached during this reporting period include scientists from industry, government, and academiathrough two talks given at international conferences (American Society for Microbiology Microbe Meeting [June, Atlanta, GA]and the International Congress on Plant Pathogenic Bacteria + Biocontrol Meeting [July, Blacksburg, VA]). Additionaly, one PhD student was reached through laboratory mentorship on this project. Changes/Problems:The biggest impediment to this project has been difficulty in hiring a postdoc. The first applicant whom I offered the job to wasn't able to get a visa for 12 months. I retracted the offer and have made a new offer for postdoc who currently resides in the US. I anticipate having this postdoc working on this project in April 2025. What opportunities for training and professional development has the project provided?This project has provided training for 1 graduate student and 1 technician. In addition to research training, the PhD student has also engaged in professional development by attending and presenting a poster at an international scientific conference. How have the results been disseminated to communities of interest?Results have been disseminated to scientific research communities through talks at two international conferences. What do you plan to do during the next reporting period to accomplish the goals?Aim 1: Complete diversity-related experiments in a gnotobiotic system. Aim 2: Initiate experiments related to chemical biocide treatment of disease suppressive communities. Aim 3: Initiate work to isolate identified Pseudomonas and Xanthomonas populations for suppressive communities.

Impacts
What was accomplished under these goals? Aim 1: to adequately address the question of starting diversity and its effects on disease suppression, it was neccessary to establish a tomato gnotobiotic system in my lab. We've made significant progress on this project. We are able to now grow tomato plants gnotobiotically in a way that allows us to infect them with our target pathogens. We will now be able to proceed with assessing the affect of community diversity on disease suppression dynamics. Aim 2: Nothing to report Aim 3: Analysis of disease suppressive communities toward Pseudomonas syringae pv. syringae (bacterial speck) indicate multiple non-syrignae Pseudomonas populations (3-7 populations, depending on passage number and type of analysis) and Xanthomonas (2 populations) that are enriched in disease suppressive communities compared to non-suppressive communities.

Publications