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April 09
Editorial Board Awards First Best Student Paper

To recognize the work of early-career scientists, the MPMI editorial board has implemented a new award series to honor the best paper published by a student first author. For 2020, that award goes to Sarah Pottinger for her paper “Optimizing the PBS1 Decoy System to Confer Resistance to Potyvirus Infection in Arabidopsis and Soybean.” 

“I found Sarah’s work on engineering PBS1 as a modifiable decoy to be innovative and creative, and the possibility of creating novel resistance traits in crops has exciting implications for agriculture,” said Jeanne Harris, the MPMI editor-in-chief. “In addition, I appreciated the logical way she leads her reader through the reasoning behind her experiments and subsequent conclusions.”

MPMI_Sarah Pottinger.jpgSarah Pottinger is currently pursuing a Ph.D. at the Roger Innes lab at Indiana University, Bloomington, where her research focuses on investigating the Arabidopsis RPS5/PBS1 decoy system to optimize plant immune responses. She is exploring the use of proximity-based labeling to identify possible signaling partners for RPS5 as well as working towards elucidating a structure for PBS1 and RPS5. She hopes to graduate in 2022 and pursue postdoctoral studies in NLR signaling and specificity.

The MPMI editorial board also identified the following papers as honorable mentions: 

Structural Requirements of the Phytoplasma Effector Protein SAP54 for Causing Homeotic Transformation of Floral Organ
Marc Benjamin Aurin, et al.

Prediction and Characterization of RXLR Effectors in Pythium Species
Gan Ai, et al.

Chitin Triggers Calcium-Mediated Immune Response in the Plant Model Physcomitrella patens
Giulia Galotto, et al.

March 29
A Novel Role of Salt- and Drought-Induced RING 1 Protein in Modulating Plant Defense Against Hemibiotrophic and Necrotrophic Pathogens

​Many plant-encoded E3 ligases are known to be involved in plant defense. Ramu et al. report a novel role of E3 ligase SALT- AND DROUGHT-INDUCED RING FINGER1 (SDIR1) in plant immunity. Their research suggests that SDIR1 is a susceptibility factor and its activation or overexpression enhances disease caused by P. syringae pv. tomato DC3000 in Arabidopsis. 


March 22
IS-MPMI Interactions - Issue 1, 2021
2021-Q3 IS-MPMI Interactions Issue 1 (copy)

Dr. Valerie M. Williamson, professor emeritus at UC Davis, in the Department of Plant Pathology, was recently interviewed by Ani Chouldjian and Jennifer D. Lewis concerning her career at UC Davis and her studies on the Mi gene. The Mi gene is found in tomato and confers resistance to root-knot nematodes, such as Meloidogyne incognita, which infect thousands of crops worldwide.
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Also in this issue...
In recognition of her contributions to the scientific community as an educator, mentor, and researcher, Dr. Barbara Kunkel was named a 2020 AAAS Fellow. Yeram Hong and Jennifer D. Lewis interviewed Dr. Kunkel about her career, female role models in science, and diversity and inclusion in the scientific community.
Dr. Jan Leach is the 2020 recipient of the APS Award of Distinction. This honor is presented to persons who have made exceptional contributions to plant pathology. Dr. Kamal Kumar Malukani recently interviewed Dr. Leach to learn more about the qualities needed to become a leader in plant pathology.
Dr. Pamela Ronald was recently awarded the 2020 World Agriculture Prize for her achievements in agricultural research and science education. Nick Colaianni interviewed Dr. Ronald to learn more about her accomplishments, the challenges faced in food production, and how science is being used to address these issues.
Kelley Clark and co-authors demonstrate the effect the SDE1 protein from the citrus greening (huanglongbing) pathogen can have on plants. Their results show that the effector is an important virulence factor that induces premature senescence-like responses in both Arabidopsis and citrus host plants.
IS-MPMIConnect, the society’s exciting new virtual discussion space, hosted two events in February. The symposium held on February 17 focused on Mental Health and Dealing with Failure and the event on February 24 featured conversations with Dr. Morgan Halane.
Join IS-MPMIConnect on March 29 for the complimentary LGBTQ+ Webinar, where scientists at various stages in their professions will share their experiences with inequality and bias in STEM. Register today!
Join IS-MPMIConnect on April 14 for a conversation with scientists who are successful academics with disabilities at various stages in their careers. Register today!
Focus Issue Editors Jacquie Bede, Kenichi Tsuda, and Jeanne Harris are inviting research and review articles that explore the complex interactions between plants, microbes, and the abiotic environment. Articles highlighting translational research, as well as fundamental understanding, are welcome. Learn more about this focus issue.
There are currently 11 What’s New in MPMI! virtual seminars available for viewing. Coming up next, Kenichi Tsuda will discuss Top 10 Question #5: Does ETI potentiate and restore PTI—or is there really a binary distinction between ETI and PTI? Register today!
Diversity and inclusion are core values of the International Society of Molecular Plant-Microbe Interactions. As an international society, it is our priority to increase diversity and facilitate change.
To draw our community together, IS-MPMI gathered virtually for the second of two workshops titled Taking MPMI Discoveries to the Field. These workshops highlighted efforts to translate molecular discoveries to the field and address MPMI Top 10 Question #3: How can we translate basic research into emerging crop plants?
IS-MPMI is excited to announce the 2021 Congress: eSymposia Series, which will take place online with a series of three separate events starting this summer! Abstract submissions open later in March. Stay tuned for more details about this opportunity to share your research and network with colleagues at this virtual scientific event.
Take the IS-MPMI Congress Series Survey
We are always looking for content for Interactions. Please contact Interactions Editor-in-Chief Dennis Halterman with questions or article ideas.


March 19
InterView with Professor Emeritus Dr. Valerie Williamson

Ani Chouldjian and Jennifer D. Lewis

Ani Chouldjian


Front row (left to right): Ilea Chau, Jamie Calma, Yuritzy Rodriguez, Yuan Chen, Karl Schreiber. Back row (left to right): Jana Hassan, Hunter Thornton, Jennifer Lewis, Maël Baudin, Jacob Carroll-Johnson, Jack Kim.

Dr. Valerie M. Williamson

 Ani Chouldjian is currently a senior at the University of California, Berkeley, majoring in microbial biology. She is interested in plant–microbe interactions, infectious diseases, and genetics. After graduation she wishes to take a year or two off from school to pursue research opportunities and later enter a microbiology and immunology Ph.D. program.

Jennifer Lewis is a principal investigator at the U.S. Department of Agriculture and an adjunct associate professor at UC Berkeley. Her lab studies the plant immune system and its response to the bacterial pathogen Pseudomonas syringae. The Lewis lab is committed to diversifying plant sciences. To encourage this, they are performing interviews with prominent scientists in the field to discuss their research and their perspectives on diversifying science.

Dr. Valerie M. Williamson

Dr. Valerie M. Williamson is a professor emeritus at UC Davis in the Department of Plant Pathology. Throughout her career at UC Davis, she has studied the Mi gene, a gene found in tomato, which confers resistance to root-knot nematodes, such as Meloidogyne incognita. M. incognita infects thousands of crops and forms biotrophic interactions with host roots. These nematodes establish feeding sites on tomato plant roots and release chemicals that induce nuclear division of root cells without cytokinesis, leading to the formation of enlarged cells called galls. The Mi gene, like other resistance genes, has conserved leucine-rich repeat (LRR), leucine zipper (LZ), and nucleotide binding-site (NBS) domains, which allow for pathogen recognition and signal transduction; therefore, tomato plants that have this gene are resistant to root-knot nematodes.

Dr. Williamson’s greatest scientific achievement was cloning the Mi gene, which allowed for its insertion into plants that are susceptible to root-knot nematode infection. This gene was discovered in a wild tomato plant and had other “bad” genes associated with it. Cloning the gene allowed Dr. Williamson’s lab to insert the Mi gene, alone, into other plant genomes to see it could confer resistance to nematodes. When asked why she thinks her research is important for the future, Dr. Williamson said,

This root knot nematode is all over the world, every continent has it, except Antarctica; it’s a huge problem in agriculture everywhere, and the way it’s controlled is with pesticides. And, they’re nasty pesticides, and there is a need to come up with new control measures. So, modifying [plants] with the Mi gene would be another control. Another project that I’ve been working on for the past 10 years is trying to figure out what attracts nematodes to roots. If you could understand what attracted them to roots and repel them, or trap them so that they are not attracted to roots anymore, that would be another way of controlling them.

Dr. Williamson’s discovery and cloning of the Mi gene was monumental; however it took some time for her to find what she is truly passionate about. Dr. Williamson grew up in a town in New Hampshire and had never planned to become a plant pathologist. Instead, her plan had been to become a medical technician. She said, “I was assuming that I would probably do some kind of medical technician type of work, because that’s the only thing I knew about that would be a good career. I loved biology, and I had always loved biology.”

As a first-generation college student, she attended Northeastern University for her undergraduate education, where she participated in a cooperative education program. The program encompassed six months of schooling and six months of clinical experience that focused on blood research. However, this type of research did not interest her. She said, “I did some karyotyping of human chromosomes, drawing blood, and analyzing blood—but I didn’t really like that.”

While looking for other research opportunities during her undergraduate education, Dr. Williamson was discouraged at times from pursuing a career in science and faced gender-based discrimination. She said, “Yes, there have been discouraging things. When I was an undergraduate and was doing these research stints in different places, there was one place I went to. They said that they had never had a woman before, and if they hired me, they would have to put in a new restroom.”

Although she was discouraged at times, Dr. Williamson did not give up. After graduation, she married a man in the army and moved to Alaska with him, where she obtained a job at the University of Alaska’s Institute of Marine Science. There she did research on trace metal contaminants of sea water; however, she was more interested in the biological samples that her colleagues were collecting. She said, “The people around me were collecting biological samples, and I thought that was much more interesting. I was frustrated because I was really interested in science, but I couldn’t do what I wanted to do. When you’re a technician, you can’t do what you want to do. You have to do what you’re assigned.”

Wanting to learn more about research, Dr. Williamson applied and was accepted into a biochemistry graduate program at UC Davis. Her thesis work was on RNA polymerase in Bacillus subtilis, and she received her Ph.D. degree in biochemistry in 1978. After obtaining her Ph.D. degree, Dr. Williamson became a postdoctoral fellow at the University of Washington in Seattle, where she worked on alcohol dehydrogenase in yeast. She said, “I got excited about alcohol dehydrogenase, so I cloned the gene that encodes it, which turned out to be very useful.” Alcohol dehydrogenase is an enzyme that converts acetaldehyde into ethanol during glucose fermentation in yeast. It is used in industry to reduce ketones into chiral alcohols.

After completing her postdoc, Dr. Williamson accepted a job in Dublin, CA, at a company called Arco Plant Cell Research Institute. During this time, oil was scarce due to the Cold War, and a lot of effort was being put into biofuel production. While there, she continued studying yeast and alcohol dehydrogenase, because the company was interested in fermentation. While working at Arco Plant Cell Research Institute, Dr. Williamson noticed that her colleagues were working on plants, and so she decided to start a project on plants as well. She said, “The other people hired there were doing research on plants, so I decided to start a project on plants. I started looking into what I would like to do. I knew that I liked nematodes, because I had met some C. elegans researchers in Seattle, and I looked into plant pathogens and thought I want to do something on plant–pathogen interactions.” However, when oil prices lowered, the company decided not to pursue agricultural research anymore. The company was sold, and at the same time, a position opened up in the Department of Nematology at UC Davis.

At the time, Dr. Williamson was not confident in her abilities to become a faculty member. She said, “I did not plan on being a faculty member. I thought that was something that I could not handle. There weren’t many role models of women being successful in it. They were mostly men then.” However, when Dr. Williamson applied for the UC Davis faculty position, she got the job.

When she started working at UC Davis, Dr. Williamson did feel the pressure of being one of the only women in a faculty position. She said, “When I first started at UC Davis, a lot of the committees I would get put on I would be the only woman there. I would be stuck onto all these committees because they wanted to have a woman there. That’s kind of hard on the woman or minority to be the only one, and you also get stuck with a lot of stuff.” Times did improve, however; Dr. Williamson persevered and found what she was most passionate about. She has been doing research as a UC Davis faculty member on the Mi gene and root-knot nematodes ever since.

When asked if she sees growth in the inclusion of women and minorities in STEM, she said,

It’s improved enormously since I started, and I think the women are holding their own really well. It’s not like we had to put them there so that we could have more women. We have a better proportion [of women]. They are really making major contributions and that helps too, because then you get more [women] in. They see that women can do this, and they can do a really good job in this.

There are a lot of young people who don’t realize that [research] is a career option, and for them to see it, they need to be given chances in high school or early undergrad [courses] to just see what science is.

Minorities have been harder to get in science. Maybe they are still at the stage where they need to be exposed more. Interacting with high-school teachers is a good way [and] having summer programs where they come in and look at labs and hang around the labs. It’s really good to have undergraduates in the lab, especially [students] who have not been exposed to science and have these programs where they come in and make friends with people who have been more exposed to science.

Although Dr. Williamson is now retired, she continues to perform research. Mi gene-resistant nematodes have been found throughout California; therefore, Dr. Williamson is initiating efforts to find differences between resistant and nonresistant nematodes through comparison of their genomes.

In her free time, Dr. Williamson likes to travel, be outside, and hike along the coast at Point Reyes and Bodega Bay. She also likes to garden because she can “look at [her] plants and think about their diseases.”

March 19
InterStellar: Interview with Newly Elected AAAS Fellow Dr. Barbara Kunkel

Yeram Hong 


Front row (left to right): Ilea Chau, Jamie Calma, Yuritzy Rodriguez, Yuan Chen, Karl Schreiber. Back row (left to right): Jana Hassan, Hunter Thornton, Jennifer Lewis, Maël Baudin, Jacob Carroll-Johnson, Jack Kim.

Dr. Barbara Kunkel

Yeram Hong and Jennifer D. Lewis

Yeram Hong is an undergraduate student at UC Berkeley in her third year. She is double majoring in forestry and genetics and plant biology. From a young age, Yeram was interested in the natural environment, with a particular interest in plant biology. Her current research interests include protein function in plant nuclear membranes and bacterial plant pathology. Outside of academia, Yeram enjoys drawing, caring for her many houseplants, and reading literary fiction.

Jennifer Lewis is a principal investigator at the U.S. Department of Agriculture and an adjunct associate professor at UC Berkeley. Her lab studies the plant immune system and its response to the bacterial pathogen Pseudomonas syringae. The Lewis lab is committed to diversifying plant sciences. To encourage this, they are performing interviews with prominent scientists in the field to discuss their research and their perspectives on diversifying science.

Dr. Barbara Kunkel

Dr. Barbara Kunkel is a professor at Washington University in the Department of Biology, where she leads a research group and teaches courses in general and plant biology. Her lab is interested in the complex biological communication between bacterial plant pathogens and their hosts, as well as the bacteria’s virulence mechanisms. Her research group takes a genetic and molecular approach in looking at both bacteria and their plant hosts to develop a more clear and integrative view of disease. Currently, Dr. Kunkel is interested in investigating the molecular mechanisms of disease caused by Pseudomonas syringae in Arabidopsis thaliana. More specifically, she works to understand how auxin, a plant growth hormone, may play a role in these plant–bacteria interactions. She is particularly interested in understanding how bacteria sense auxin and respond to it and the significance of this interaction. Prof. Kunkel’s research is important in obtaining a fundamental understanding of the virulence strategies pathogens use. This knowledge can be used in the future to develop breeding, cultivation, and control strategies to address the global issues of crop failure and agricultural pathogen outbreaks. By providing fundamental knowledge about the interactions between bacterial pathogens and plants, she believes that her discoveries may be crucial to developing novel biological technologies to address crop losses from disease.

One of her major discoveries was the identification of the coronatine virulence factor as a jasmonic acid mimic in the Arabidopsis–Pseudomonas pathogenic interaction. Her lab stumbled upon CORONATINE INSENSITIVE 1 (COI1), a gene that encodes the coronatine receptor, while examining plant mutants that were particularly resistant to bacterial infection. At the same time, another researcher in her lab, who was focused on the bacterial side, isolated several mutants in a biosynthetic gene cluster in P. syringae that coded for coronatine. Connecting these observations, her lab realized coronatine was particularly significant. Although coronatine had been previously identified, her lab was able to find their “first indication that manipulation of plant hormone biology [aside from purely defense hormones] was important in these pathogen interactions.” They had discovered a virulence factor that the pathogen used as a hormone mimic to modulate the biology of its host!

To recognize her considerable and valuable contributions to the scientific community as an educator, mentor, and researcher, Dr. Kunkel was awarded the AAAS Fellowship as one of the elected Fellows of 2020. In response, Dr. Kunkel commented: “I was surprised to tell you the truth…but I was also very thrilled [as] it gives me some exposure that I would not have had otherwise.” This opportunity allows people to learn about her research and become more interested in the topics that she is researching. Through her achievement, she is paving the way in science as a role model for future women scientists to look up to and have the conviction that success is possible.

Despite her research successes, she had not originally planned on entering this career path. From a young age, Dr. Kunkel had a love for horses and other large animals and dreamed of becoming a veterinarian. Following her dreams, she attended the University of California, Davis. There, she became drawn to the pastoral life of working in the agricultural sector and began studying agricultural sciences. However, this was not meant to be, as she stated, “it was unrealistic because I’m not a farm kid, I’m a city kid.” In her second year of college, Dr. Kunkel found her true passion in a genetics course taught by Dr. Francisco Ayala. She became a genetics major, specializing in plant biology and bacteriology.

After graduating from UC Davis, Dr. Kunkel was unsure about her next steps. However, she loved to learn and was just being introduced to the world of scientific experimentation; graduate school seemed like the next step. Interested in symbiotic relationships, she looked for a graduate school where she could study plant–microbe interactions. Although she was not able to find the right opportunity in this line of interest, she obtained her Ph.D. degree at Harvard studying gene expression in Bacillus subtilis in Dr. Richard Losick’s Lab. For her postdoc, Dr. Kunkel decided to pursue research in the area of plant–pathogen interactions because she wanted to work with plants again and she “wanted to study a system where you could do the bacterial part and the plant host was genetically tractable.” She completed her postdoc at the University of California, Berkeley, with Dr. Brian Staskawicz, studying disease resistance in plants using a genetics approach to investigate which genes control the ability of a plant to detect the pathogen and activate defense responses.

Although Dr. Kunkel had never planned on becoming a university professor, she realized while obtaining her Ph.D. degree and completing her postdoc that she loved the scientific process. During her postdoc, Dr. Kunkel decided she wanted to run her own lab. While she was working in the Staskawicz lab researching disease resistance, she continued to wonder, “What’s the pathogen’s part in this?” She began planning to start a lab that would also study the pathogen as well as the plant host. At this time, researchers had discovered the type III secretion system (T3SS) in bacteria. Using this system, bacteria can inject into their plant hosts proteins that directly affect plant physiology and make the plant more susceptible to infection. Fascinated by the recent discovery of the T3SS, Dr. Kunkel decided that one of her first projects would be to study virulence mechanisms in P. syringae and find out more about the proteins being injected.

02Kunkel_Image2.jpgAs a woman in science, Dr. Kunkel wondered if she could manage a full-time, professional career as a professor. Her mother expressed concerns about her career path as a researcher, intimately aware of the time and dedication required for the job as Dr. Kunkel’s father was a professor of physics at the University of California, Berkeley. Although her parents did encourage her curiosity and to pursue the opportunity, her mother did not believe that Dr. Kunkel, who was in a serious relationship at the time, would be able to “be a mom with kids and a homelife and be a professor.” Along with these concerns, Dr. Kunkel found there was a lack of role models who could show her that this was in fact possible. She stated, “I wanted to look around and try to find role models or examples of what I wanted to do…[but] there weren’t a lot of role models for me at the time.” From her perspective as a professor, Dr. Kunkel emphasized the importance of role models. She said,

There has to be that first role model…. I think if you’re going to be the only woman, and if everybody is white, the only woman of color, that’s two barriers. You have to be the first one, and you have to be the role model? That’s a lot to do…. I teach a freshman biology class in which we have a lot of attrition in that first semester because it’s a challenging class. A lot of people go, ‘Oh my gosh, I can’t handle this.’ And, what we think would be helpful would be…that all the students could see themselves as scientists regardless of their background, [whether they’ve] taken AP Biology [or are] the first generation to go to college [or if] they’re black. How can we help them see themselves as succeeding there?

Another difficulty with being a woman in science was that she found it hard to be recognized for her accomplishments. When she was receiving more opportunities than some of her male colleagues, she said, “Some of them [said], ‘You’re getting all of these interviews because you’re a woman.’ Like ouch, I’m a good scientist and I’m a woman.” She also recalled a story from her years as a postdoc:

I think I did experience some of that when I was a postdoc, and I remember at some point [my co-postdoc] was trying to tell the boss about my results. And finally I just said, ‘Let me tell him. I did this.’ I don’t know if he was consciously trying to grab the credit for it, if he was thinking I couldn’t speak for myself, or what was he doing. The funny thing is this guy is a very very good friend of mine to this day. We had a few rough times in there where I had to just say, ‘Back off guy!’

Despite these past experiences, Dr. Kunkel believes that things are changing for the better. She believes that while the situation is still not perfect, there has been an increase in the number of role models that women can look to to know that they can actively pursue science. With additional focus on the effect of implicit bias and more strategic dispersal of funding for small labs and minorities to pursue research, Dr. Kunkel believes that we can continue to work toward a more diverse and inclusive scientific community.

When she is not busy in her lab, Dr. Kunkel loves to be outdoors. She enjoys hiking and gardening, which she says could be why she likes plants so much. She is also an avid reader and is currently part of a book club where she is exposed to many different genres and authors. When asked about her favorite types of books she exclaimed, “I like books with strong women!”

March 19
InterStellar: Interview with APS Award of Distinction Honoree Dr. Jan Leach

Kamal Kumar Malukani

Dr. Jan Leach (Colorado State University) was the recipient of the 2020 Award of Distinction from The American Phytopathological Society. This award, the highest honor APS can bestow, is presented on rare occasions to persons who have made truly exceptional contributions to plant pathology. Dr. Kamal Kumar Malukani, a postdoc in the lab of Dr. Ramesh V. Sonti at the CSIR-Centre for Cellular and Molecular Biology in Hyderabad, India, recently interviewed Dr. Leach to learn more about the qualities that one needs to become a leader in the field of plant pathology.


​Dr. Kamal Kumar Malukani

Dr. Jan Leach

1. Many scientists, especially those early in their careers, find it difficult to manage a balance between their professional and personal life. How do you manage it?

I don’t know that I did manage it particularly well! My husband, also a plant pathologist, and I started our faculty positions at the same time, so we were both going through the tenure and promotion process together. We shared an understanding of the pressures and demands of our positions. We respected and, very importantly, supported each other’s choices and challenges, which really helped as we worked through the ranks. We joked that we often passed each other in the door, one coming and one going, much of the early parts of our careers. So, I would say understanding and respecting each other’s situation played a big role.

2. Thinking back to the beginning of your career, can you provide one or two things you wished you had known that might have made starting your career easier?

As passionate scientists, we focus our early training on getting deeper into the science. We are frequently very focused on learning what is needed to support our research. But, unfortunately, we are often not well-trained in how to manage people, which is a critical part of running a successful lab. For me, it was “on-the-job” learning, and as a young faculty member trying to build my program, it was a hard go. Fortunately, I found good mentors to reach out to for sound advice. I still do that; more than 30 years of experience, and I still reach out to mentors, some decades younger than me, for guidance on how to handle tough people problems.

3. What do you believe is the biggest question in the field of MPMI today, and why?

One of our biggest questions is how we will identify and stabilize plant disease resistance in the face of a changing climate. Adapting crops to withstand disease in the face of changing temperatures and unpredictable weather patterns is not trivial. We have observed that some disease-resistance genes lose efficacy with a few degrees of increase in temperatures. Other resistance genes are more effective at high temperatures but may fail under drought conditions. Successful crop production in the future will likely depend on more complex solutions, discovered by studying the plant, pathogen, and environment as an interacting system (phytobiome) and integrating more diverse options into our tool kits. Successful translation of those solutions will likely require those of us in MPMI to work even more closely with those nearer to the field and the growers, including breeders, agronomists, and extension specialists.

4. You have been involved in a lot of science, as well as the administrative side of work. How do you manage this transformation?

The secret is working with talented, independent, and smart people who are patient with my split position. I have kept my research program running because it is the candy in my job, i.e., the part of the job where I am most comfortable and find the most joy. It also helps keep me grounded in the issues and challenges faced by the faculty I serve as associate dean for research. Balancing the two parts of the job is difficult, and I battle the constant feeling that I am not doing either job very well. But, we all have a limited time, and I try to give the best output in both parts with the help of people around me.

5. What advice would you like to give to emerging scientist that will help them in the long run?

Probably the best advice I received as an assistant professor was “Choose your battles wisely!” In other words, consider carefully if this is a cause or battle that is really important and worth investing your time and energy. You only have so much energy and time…conserve them for the important causes and issues.​

March 19
InterStellar: Interview with World Agriculture Prize Recipient Dr. Pamela Ronald
Nick Colaian​ni​

Nick Colaian​ni

I had ​the pleasure of interviewing Dr. Pamela Ronald who was recently awarded the 2020 World Agriculture Prize for her ach​ievements in agricultural research and science education. Dr. Ronald is a leader in the research field of plant responses to environmental and pathogen stresses. Additionally, she is an advocate and educator for sustainable food practices and modern crop breeding strategies. She has a fabulous TED talk and has written a book with her husband on modern crop science and organic farming practices titled Tomorrow’s Table: Organic Farming, Genetics and the Future of Food. This Q&A session was designed to learn more about her accomplishments, understand the challenges humanity faces in fo​od production, and the ways science has and continues to address these issues.

1. In your own words, can you provide a brief introduction of your research and interests?

“I have been working on the interaction between plants and microbes for many years. My interest in this research started when I was an undergraduate. My plant physiology professor at Reed College taught me about plant–microbe interactions, and it sparked my interest. Then, while doing my masters at Stanford, Dr. Brian Staskawicz came and gave a talk on his lab’s work, and it left an impression on me. After my Ph.D. work, I decided to work in Dr. Staskawicz’s lab. There I focused on plant–microbe interactions, where I have now spent a bulk of my career.”

At the helm of her own lab, Dr. Ronald and her team identified Xa21, a receptor in rice, using positional cloning. This receptor confers resistance to the devastating Xanthomonas oryzae pv. oryzae pathogen. Almost immediately after publication, “a colleague of mine that I had known for several years, Dr. Dave Mackill, came by my office and asked if I would help him isolate another gene in rice that plays a role in stress tolerance. I was immediately interested.” This gene, Sub1A, turned out to be instrumental for conferring tolerance to submergence. Its discovery led to an, “exciting international project to create flood-tolerant rice varieties for farmers in India and Bangladesh.”

2. Can you go a bit more in-depth about the creation and distribution of Sub1A rice varieties?

“Well this whole process was started by the International Rice Research Institute (IRRI). The mission of IRRI is to help abolish poverty and hunger in regions that depend on rice for most of their calories.

Rice fields in India and Bangladesh were constantly being flooded, resulting in devastating yield losses, so farmers looked to the scientists at IRRI to help. At the time, IRRI had built up a large and diverse rice seed collection, which they used to screen rice varieties for submergence tolerance.

Dave Mackill had worked in South Asia before working at UC Davis and knew how important this work was. Researchers at IRRI had identified a rice variety with tolerance to submergence. Dave then mapped the submergence tolerance (Sub1) trait as a quantitative trait locus (QTL). This was when Dave came to me and asked if we could collaborate on isolation of Sub1 using positional cloning. We were successful and named the key gene Sub1A.

Dave used marker-assisted breeding to introgress Sub1A into commonly used rice varieties. This breeding practice is not considered a genetically modified organism (GMO) and is not regulated. IRRI researchers collaborated with breeders at breeding stations in India and Bangladesh to test the performance of the Sub1 varieties.” Last year, 6 million farmers in India and Bangladesh grew Sub1 rice with an average yield advantage of 60% after flooding.” See this perspective for more information.

Dr. Pamela Ronald

​​3. If you were to make the argument for GMO products to someone against it, what would you tell them?

“Well, I would first try to understand what they were afraid of. The term GMO means something different to everyone. Interestingly, GMO isn’t even used by the FDA because genetically modified organism doesn’t accurately describe any breeding process really. Often, a person who identifies as ‘anti-GMO’ is afraid of large corporations like Monsanto, or they heard that ‘GMOs’ require more chemicals, and they don’t like that. This is why it’s really important to understand the root of each person’s fears of GMOs, so you can narrow the discussion to address individual questions.

When trying to explain to a group of people why modern genetics is useful in agriculture, I think it’s important to give specific examples. That’s the one thing that just changes people’s mind. Two examples I usually give are genetically engineered papaya that are resistant to the deadly Papaya ringspot virus and Bt eggplant in Bangladesh that reduces the need to spray chemical insecticides. Both genetically engineered crop varieties have improved plant yields and the lives farmers.

Now in the world of COVID-19, more people are familiar with viruses and their infective nature. This is a good example, because some people may be interested to know that viruses also infect plants. This allows you to then engage people by using their knowledge about the vaccine for COVID-19 to explain the techniques used by plant scientists to ward off pathogens. Also, something I realized while writing my book was, why would the average American know a lot about farming? And, how much would they actually know about it? This is also a really important thing to keep in mind when talking about GMOs with people. Many people may not understand or know the farming practices used today and what challenges farmers face.”

4. In your point of view, what are some of the toughest challenges facing agriculture right now? And, how might agriculture look in 2040 to address these problems?

“I think problems associated with climate change, like increased flooding, which I’m now more aware of, droughts, and unpredictable insect infestations, like the fall armyworm sweeping through Africa, are going to be tough. There are scientists and modelers trying to predict new infestation events, but it is proving very difficult. The work we do now is similar to what breeders have been doing for 100 years or so, but we now have to work smarter and faster to keep up with all of the changes occurring around the world.

Additionally, we will have to start growing more food, while reducing emissions. This is something that wasn’t really being talked about when I first entered the field. It was more about reducing chemical inputs. So, now we have to also think about enhancing soil fertility, reducing greenhouse gas emissions, and using water more efficiently.

This is seemingly a daunting task; however, Dr. Ronald is optimistic that scientists can work toward solutions. “The field is rapidly advancing, and new technologies are now starting to be developed and tested to address these problems.”

5. In your mind, what are some of the most intriguing questions concerning pattern recognition receptors and their role in plant immunity?

“Well, I think an emerging topic that is still sort of a black box is the relationship between development and immunity. There is great work from Dr. Joanne Chory and others on the SERK receptors that are involved in both immunity and development. When this relationship was discovered years ago it was pretty surprising, and now there are many great examples of the relationship between development and immunity.

I think the other complicated aspect of this area is that immunity has been traditionally thought of as a linear concept—immunogen interacts with receptor, and this induces a linear pathway that results in a response. However, we now know that the responses to immunogens are much more complex than this. For instance, there are receptor complexes and receptors that can double dip into immunity and development. I think trying to sort out the balance and inner workings of this is really fascinating and will be studied for a long time.”

6. For pattern recognition receptors (PRRs) and resistance (R) genes, what needs to be done to increase their use and efficacy against pathogens?

“There are examples where different resistance genes have been stacked [placing multiple R genes into a plant], and this provided additive and, hopefully, more durable resistance. I think some steps to improve the process will be trying to predict how resistant and durable these added genes will be in a crop plant. This involves doing epidemiological studies where you think about the population diversity of the pathogen in the field. This allows you to predict the types of mechanisms the pathogen has to overcome and the methods being placed into plants to confer durable resistance. You really need to know the effector repertoire of a pathogen population and the interactions they have with the receptors of interest. This allows you to answer the question, ‘Are there pathogen strains in the field that can already overcome the R gene(s) or PRR(s) being added?’ There really is no shortcut to the process of engineering durable resistance.

We are still learning a lot about utilizing plant immune components to increase pathogen resistance. For example, being able to introduce many R genes at a single time in a cassette of genes would be a great step forward. Currently, it takes a long time to breed many R genes into a population. If people become more accepting of genetic engineering, this could decrease the time needed to introduce resistance genes into plants, which is exciting.

For a long time, there has been the hypothesis that PRRs that recognize conserved virulence factors or immunogens would be more durable in the field than R genes. However, I don’t think this has been very well validated or tested in the field. One reason may be because much of the research on PRRs, like FLS2, is carried out on non-crops. So there are very few studies that examine if these theories hold up in the field. Even for Xa21, where plants carrying this gene have been grown in the field for years now, there really hasn’t been any thorough epidemiological studies to determine if this resistance is indeed more durable than the resistance provided by other types of resistance genes such as NBS-LRR genes. Researchers have discovered bacterial strains that evade Xa21 in the field; however, to my knowledge it is not known if they become problematic to farmers. So, what does that mean? Does the evolution of the ability to evade Xa21-mediated immunity result in strains that are compromised in virulence somehow? You really can’t determine this unless you do large-scale field trials that look at the pathogen population over time.”

March 19
InterConnections: Get to Know Kelley Clark

​​The December 2020 Editor’s Pick for MPMI is “Sec-Delivered Effector 1 (SDE1) of ‘Candidatus Liberibacter asiaticus’ Promotes Citrus Huanglongbing,” in which Kelley Clark and co-authors demonstrate the effect that the SDE1 protein from the citrus greening (huanglongbing) pathogen can have on plants. Their results show that the effector is an important virulence factor that induces premature senescence-like responses in both Arabidopsis and citrus host plants.


Sec-Delivered Effector 1 (SDE1) of ‘Candidatus Liberibacter asiaticus’ Promotes Citrus Huanglongbing

03Clark_Image1.jpgName: Kelley J. Clark

Current position: Postdoctoral researcher, University of Arkansas (located at USDA-ARS Salinas, CA).

Education: Ph.D. degree in microbiology and plant pathology at the University of California, Riverside, and B.S. degree in plant sciences at the University of Arizona.

Non-scientific Interests: Gardening, traveling to national parks, hiking, walking my cat.

Brief Bio: Currently, I am a postdoctoral researcher for the University of Arkansas, but stationed in Salinas, CA, at the USDA-ARS facilities. My research project is on spinach downy mildew, and I am located in the Salinas Valley because it is the “salad bowl of the world,” producing the majority of the leafy greens we consume! The research recently published in MPMI is the final chapter of my Ph.D. thesis from my time at UC Riverside under the supervision of Prof. Wenbo Ma. Our overarching goal was to understand how an effector of Candidatus Liberibacter asiaticus contributes to huanglongbing (HLB) disease progression. More specifically, for this publication we wanted to understand how the effector SDE1 contributes to leaf yellowing in Arabidopsis and how this relates to HLB yellowing symptoms in citrus.

This project challenged me on many levels, both intellectually and emotionally, especially as my passion for research progressed and I grew as a scientist. The HLB-associated pathogen, Ca. L. asiaticus, is obligate, which presents many obstacles, but also opportunities, for novel research. During my Ph.D. studies, I was fortunate to learn several new techniques, have access to state-of-the art technology, and collaborate with distinguished scientists. For this project, we had access to SDE1-transgenic citrus, which would not have been possible without help from our collaborators Prof. Nian Wang and Dr. Zhiqian Pang at the University of Florida. Additionally, we implemented NanoString technology to directly measure the transcript quantity of specific genes in citrus. Although this technology is widely used in medical research, it holds tremendous potential for plant–microbe interaction research, as well as other fields of study.

Giving a presentation on citrus pathogens to visitors at the California Citrus State Historic Park.
In addition to gaining a technical skill set, I grew passionate about citriculture from studying its history in Riverside, CA. When I moved to Riverside to pursue my Ph.D. research, I volunteered at the California Citrus State Historic Park. The park consists of more than 250 acres of citrus groves showcasing more than 80 different citrus varieties and includes a museum highlighting the history of citrus in California. Did you know that Riverside is home to the parent Navel orange tree planted by Eliza Tibbets in 1873? The tree is still alive today, and you can visit it on the corner of Magnolia and Arlington Streets, but due to the threat of HLB, the tree is covered with a mesh tent to keep out the insect vector that transmits Ca. L. asiaticus. Volunteering at the park gave me the opportunity to immerse myself in the rich culture of citrus and see others admire it is as well, which drove my research efforts, since HLB continues to threaten not only the citrus industry, but our connection to its past, present, and future.

I look forward to working on more challenging and insightful projects in the future, incorporating both the knowledge I gained from this research and the inspiration I drew from learning about the agricultural history of a specific crops.

LinkedIn: www.linkedin.com/in/kelley-j-clark

Twitter: @KelleyJ_Clark

March 19
Call for Papers! Announcing the 2022 MPMI Focus Issue Topic

04MPMI_Focus_Issue.jpgInteractions between plants and microbes are shaped by the physical world that surrounds them. In nature, the abiotic environment is complex, and factors such as nutrient and water availability, humidity, wind, carbon dioxide levels, salt, pollutants, and temperature all affect the growth and physiology of plants and microbes, as well as their interactions.

Much of our mechanistic understanding of plant–microbe interactions comes from experiments done under carefully controlled conditions. How do aspects of the abiotic environment affect these plant–microbe interactions? Conversely, how do plant–microbe interactions affect host response to abiotic stress?

The importance and immediacy of these questions was reflected in the selection of the interactions between plants, microbes, and environmental conditions as question 2 of the Top 10 Unanswered Questions in MPMI.

Focus Issue Editors Jacquie Bede, Kenichi Tsuda, and Jeanne Harris are inviting research and review articles that explore the complex interactions between plants, microbes, and the abiotic environment. Articles highlighting translational research, as well as fundamental understanding, are welcome. We look forward to assembling an issue that highlights the excellent research in this area!

The submission deadline is July 24, 2021. Learn more about this focus issue.

March 19
What’s New in MPMI! Seminar Discusses the Binary Distinction Between ETI and PTI

04Tsuda_Photo.jpgThe freely available What’s New in MPMI! virtual seminar series has been a great way for IS-MPMI members to stay connected to their science and for MPMI journal authors to present their work to a global audience. There are currently 11 seminars available for immediate viewing.

Coming up next, we are excited to host Kenichi Tsuda, who will discuss Top 10 Question #5: Does ETI potentiate and restore PTI—or is there really a binary distinction between ETI and PTI? Read his review of the topic. This free seminar will be held March 22 at 8:00 p.m. CDT (9:00 p.m. EDT) and March 23 at 9:00 a.m. (Beijing, CST). Access this page to register in advance to attend or check back to watch it later.

Other Upcoming Seminars

April 12, 2021, 10:00 a.m. CDT (11:00 a.m. EDT)

Barbara Kunkel presents Dual Role of Auxin in Regulating Plant Defense and Bacterial Virulence Gene Expression During Pseudomonas syringae PtoDC3000 Pathogenesis.”

May 3, 2021, 10:00 a.m. CDT (11:00 a.m. EDT)

Cara Haney and David Thoms discuss Top 10 Question #1: How do plants engage with beneficial microorganisms while at the same time restricting pathogens?

Register for all seminars or watch past seminars here.

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