CHEMICAL PRIMING OF PLANT DEFENSES FOR INCREASED CROP PROTECTION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1016247
• Project Start Date: Jul 1, 2018
• Project End Date: Jun 30, 2023
• Program Code: [(N/A)]- (N/A)

Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523

Performing Department
Agricultural Biology

Non Technical Summary
Plants have developed several mechanisms to cope with pathogenic attack. One of these mechanisms, known as defense priming, allows plants to prepare for attack, without directly turning on defense responses. Once challenged, primed plants respond faster to pathogen attack, and display increased levels of resistance against pathogens. In this application we propose to study defense priming in the model and crop plant species elicited by plant hormones associated with plant growth. We propose to test the efficacy of these hormones as priming agents in agronomically important plant species, thus paving the way for the use of these molecules as agrochemicals in crop protection.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	1410	1040	10%
212	1530	1040	10%
212	2420	1040	80%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1410 - Beans (dry); 1530 - Rice; 2420 - Noncrop plant research;

Field Of Science
1040 - Molecular biology;

Keywords

phytohormone

crop protection

Goals / Objectives
To test the efficacy of the a plant hormone as a priming agent in agronomically important plant species, thus paving the way for the use of these molecules as agrochemicals in crop protection.Objective 1: Determine the effectiveness in disease protection in crop speciesObjective 2:Determine the effectiveness as priming agents in crop species:

Project Methods
Aim 1. Determine the effectiveness of cytokinin in the protection of model and crops plant species:While our preliminary data for Arabidopsis and dry beans is promising, we will expand our experiments to includea monocot species (rice - "Kitaaki" variety).Certified disease-free seeds will be grown in field plots of the CSU Agricultural Experiment Station (beans) or in greenhouses (Arabidopsis and rice), using a randomized experimental design and standard cultivation practices (including irrigation). Mature plants (just before flowering/bulb stage) will be treated by foliar spray with a range of concentrations of plant hormonesor a mock control. After 48 hours, plants will be inoculated by standard procedures with virulent biotrophic pathogens: Pseudomonas syringae pv. phaseolicola (dry beans) and Pseudomonas syringaepv. tomato (Arabidopsis) and Xanthomonasoryzae pv. oryzae (rice).Plants will be assessed for disease symptoms qualitatively (disease ratings) and quantitatively (bacterial growth curvesfor bacteria pathogens).Aim 2.Determine the effectiveness of cytokinins as priming agents in crop species:To be considered a bona fide priming agent, a chemical should be able to provide protection to pathogen attack, but not activate defenses directly at time of application. We will address whether these hormones function as bona fide priming agents in dry beans (for which preliminary data for a crop protection activity is already available), and in any of the other plant species tested in Aim 1 for which a crop protection activity is observed. To do so, we will assess theexpression of defense response marker genes (PR-1, PAL1 orthologues) as a measure of defense activation through qRT-PCR.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Plant scientists andplant pathologists, in both academic and industry settings. College teachers in plant sciences, through our efforts of broader impacts. Changes/Problems:The major problem this year was the COVID-19 pandemic, that limited our work hours to 50%, given necessary space limitations. It also required that our activities got shut down for almost 3 months, having a great impact in our ability to produce results. What opportunities for training and professional development has the project provided? This project has provided training and professional development opportunities to 1 graduate student. This student has been able to conduct research in plant sciences and plant pathology, and has recently been awarded a NIFA Pre-doctoral Fellowship to support other parts of this work. The student did not have the opportunity to present their work in conferences this year, given the COVID-19 pandemic. How have the results been disseminated to communities of interest? In this reporting period we have disseminated research results and information to the scientific community, through presentations of seminars in universities (University of Minnesota) and scientific conferences (Plant Health 2020- American Society of Phytopathology). We have also disseminated broader impact results in our article published in ABT. This information has also been shared withindustry and to students at CSU through classes. What do you plan to do during the next reporting period to accomplish the goals? In the next period we will address whether cytokinins can provide disease protectionto monocot species, to bacterial, fungal and viral pathogens. This is a goal that we were going to pursue this year but requiredcollaborators who were not available given the pandemic.

Impacts
What was accomplished under these goals? We have determined that cytokinins can provide disease protection to arabidopsis, canola, beans and tomato against bacterial and fungal pathogens. We are now testing whether it can provide protection against viral pathogens, through a collaboration with the University of Nebraska Lincoln. Some of this work was slowed down given the COVID-19 pandemic.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Shigenaga AM, Kroh GE, Argueso CT. Plant Disease & Climate Change: A Classroom Exercise Emphasizing Scientific Collaboration. American Biology Teacher

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:In this reporting period we have disseminated research results and information to the scientific community, through presentations of seminars in universities and scientificconferences. We have alsodisseminated research results and information to industry (Cargill) and to students at CSU through classes. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training and professional development opportunities to 2 graduate students. These students have been able to conduct research in plant sciences and plant pathology, and present their work in an national and an international conference in 2019. How have the results been disseminated to communities of interest?In this reporting period we have disseminated research results and information to the scientific community, through presentations of seminars in universities and scientificconferences. We have alsodisseminated research results and information to industry and to students at CSU through classes. What do you plan to do during the next reporting period to accomplish the goals?In the next period we will address whether cytokinins can provide disease protection against viruses, using the same crop species mentioned above. We will also addresswhethercytokinins can provide disease protection to monocotspecies, to bacterial, fungal and viral pathogens.

Impacts
What was accomplished under these goals? We have determined that cytokinins can provide disease protection to arabidopsis, canola, beans and tomato against bacterial and fungal pathogens.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: McIntyre KE, Hajdu D, Bush D and Argueso CT. Role of cytokinins in molecular priming. Plant Biology: American Society of Plant Biologists Meeting Abstract Book
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: McIntyre KE, Hajdu D, Bush D and Argueso CT. Role of cytokinins in molecular priming.XVIII Congress of the International Society of Molecular Plant-Microbe Interactions Proceedings
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Shigenaga AS, Johns S and Argueso CT. Cytokinin-mediated processes promote heat-induced disease susceptibility of Arabidopsis Plant Biology: American Society of Plant Biologists Meeting Abstract Book
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Shigenaga AS, Johns S and Argueso CT. Cytokinin-mediated processes promote heat-induced disease susceptibility of Arabidopsis XVIII Congress of the International Society of Molecular Plant-Microbe Interactions Proceedings

Progress 07/01/18 to 09/30/18

Outputs
Target Audience:plant pathologists, plant scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?two graduate students have been trained in methods of plant growth, pathogen inoculation and rating of disease resistance. These students have also been able to attend 2 international conferences. How have the results been disseminated to communities of interest?through oral and poster presentantions in international scientific meetings, as well as scientific presentationsat CSU What do you plan to do during the next reporting period to accomplish the goals?We will now address whether cytokinis can also act as a disease protection agent in monocot species, and whether this action is through priming or direct activation of defese responses

Impacts
What was accomplished under these goals? Objective 1: Determine the effectiveness in disease protection in crop species So far we have determined the effectivess of cytokinin as a priming agent in canola and beans.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McIntyre, KE; Hajdu, D; Argueso, CT. A histone deacetylase regulates cytokinin-induced priming. Plant Biology 2019, Montreal, Canada. 2018
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McIntyre, KE; Hajdu, D; Argueso, CT. Cytokinin-induced biotic priming. International Congress of Plant Pathology, Boston, MA. 2018
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Shigenaga, AM, Johns S; Fish D and Argueso CT. Cytokinin Signaling Promotes Heat-Induced Disease Susceptibility of Arabidopsis to Pseudomonas syringae pv. tomato. International Congress of Plant Pathology, Boston, MA. 2018