Environmentally Friendly Plant disease control agents for Food Security
Graduate School of Environmental and Life Science (Faculty of Agriculture)Yoshiteru Noutoshi
Associate Professor (Research Professor), Department of Environmental and Life Science, Academic Research Fellow, Okayama University
Specialized in Plant Pathology, Plant Immunology, Plant Chemical Biology
Award for Excellence, Okayama University SDGs President Award, FY2021
Research Professor Noutoshi received the Award for Excellence at the 2021 Okayama University SDGs President Awards. Please watch the following video of the activity presentation.
Research and development of plant disease control agents (Plant Activator) that contribute to sustainable agricultural production
Plant pathology exists to protect plants from disease
――First, could you briefly tell us about your specialty, plant pathology?
Plants are so-called clones or copies. Agriculture is about growing a lot of it in one place, and just as coronavirus spread once it appeared in humans, this is often the case in the agricultural field. Agriculture is not possible without controlling disease outbreaks, as both set diseases and new diseases can emerge.
For this purpose, as with human diseases, for plant diseases, we will investigate and clarify what the disease itself is, where it came from, how it works, how it is transmitted, and what it causes when it is transmitted. Both of these must be examined in detail, as the full picture cannot be revealed without an understanding of both the pathogen and plant sides. And finally, we will study how to prevent disease.
In other words, the study exists to prepare for disease so that the important industry of agriculture can be sustained.
――Are you identifying the disease?
As far as disease identification is concerned, very few universities do it, and it is mainly done by prefectural research institutes. When a farmer comes across a disease or other problem, he consults with the prefectural government, and if the problem cannot be determined on the spot, he takes it to the prefectural laboratory for detailed investigation and identification of the cause. The university's role is to educate people in such knowledge and methods and send them out to work in the field.
――Do you ever collaborate with prefectural research institutes?
Yes, we do. The prefectural government and universities in Okayama are active in exchanges, and we get together twice a year as a study group to present the current situation and share information and the mechanisms of newly emerging diseases are studied at universities.
Research to elucidate plants and diseases at the molecular level and move toward the development of new agents
――Please tell us about your research ① "Elucidation of Plant Immunity Mechanisms by Chemical Biology".
I mentioned the field earlier, but what we do at the university then is a bit more basic. We are studying how pathogens cause diseases and how plants protect their bodies, down to the genetic level.
I started out in the plant side of research, and there are several research methods, one of which is to look for mutants. For example, if plant A is not normally susceptible to disease, but plant A' is susceptible to disease, the same plant may have been weakened by some mutation. Then, we can examine what genes were broken and mutated, and find out that this gene was important for the body to protect itself. This is called genetics, and since this research method has been used for a long time, many important genes have been discovered. So we're getting to the point where we feel like we've largely done it all, or that we can't find much in that one way.
So I started researching using a method called chemical biology. What this does is sprinkle various compounds on the plants. In many cases Compounds adhere to proteins in the body.
Humans also take medicines, but how their medicines works is mainly by attaching to proteins in the body and interfering with their function. So, for example, if we sprinkle a compound on a plant and then make it sick, and if the symptom becomes weaker or stronger, we can think that this compound is doing something, that it is affecting the plant in some way. Then, when we look into how it is affected, we come up with protein. Since proteins i.e. genes, we can see that the proteins that we have come to as the cause are very important for immunity.
In other words, I study immunity by manipulating proteins with drugs and seeing the difference, rather than by damaging genes and seeing proteins disappear or mutate.
――What are the advantages of the chemical biology method?
Basically, a single gene in a living organism, including plants, produces a single protein, but in some cases, there are several proteins or genes that have the same function. For example, if there are three genes that have the same function, even if one is damaged, the other two remain and appear normal. But the compound attaches to any of the proteins expressed by these three genes, so we can see what genetics could not.
――When did you adopt the chemical biology method?
To begin with, how we look for drugs is by searching for a hit among a pile of 10,000 or 100,000 compounds. While such research has been conducted in the field of pharmaceutical drug discovery in humans, there has been little such research in plants. But there are technologies and materials that have been cultivated for a long time in pharmaceuticals, and sets of such compounds are gradually being sold. So, my boss (Dr. Ken Shirasu) at the time thought I should buy that and get started.
I started around 2005, when the world was beginning to use such research methods on plants.
――Please tell us about your research ② "Exploration and Identification of Plant Immunity Activators".
We are trying to find and take compounds that stop or strengthen the immune response of plants. As a result, we didn't mostly that stopped it, but we did get some that strengthened it. Something that strengthens means it strengthens the immune system, so it makes you more resistant to disease. So, we are continuing our research, hoping to be able to put that to practical use.
――Could you tell us about your research ③, "Elucidation of the mechanism of resistance to sheath blight disease using Minatokamojikusa "?
Since around 2009, when I first came to Okayama University, I have been participating in the study groups with Okayama Prefecture that I mentioned earlier, where companies also come to participate. I was told that there is a disease called sheath blight disease, and that it would be good if there was a agents that could strengthen the immune system against this disease. Then I decided to start research to find and investigate such things. Sheath blight disease is one of the two most important diseases of rice, but surprisingly, there has not been much research on how the disease occurs at the molecular level. If so, I thought I would be the main person to carry out the research.
We are using an experimental model of monocarpic plants, such as rice and wheat, which have pointed leaves, called Minatokamojikusa. It would be very difficult to actually grow large rice plants in a laboratory, so it was decided that we would all do research using these small plants, which are common all over the world. We started by trying to see if sheath blight disease would occur on this model plant and were able to properly reproduce the disease. Then, Does the medicines work against it? We have been researching this for a long time now.
And also, The disease is known as "sheath blight disease" because a species of mold called Rhizoctonia solani infects the leaves of rice plants and causes them to wither, producing elliptical lesion, but in fact, other crops are infected with many of the same fungi. There is a lot of damage because the fungus is in the soil and the moment a seedling or seed is planted, it is immediately infected and attacked. Therefore, we have been conducting research on Rhizoctonia solani itself.
――Please tell us about your research project ④, "Elucidation of the mechanism of action of antagonistic microstructures that inhibit Grapevine crown gall disease".
This is another connection from the study group. First, the prefectural government was asked to investigate some grape seedlings that were not in good condition. They found out that they were a disease called Grapevine crown gall disease, caused by bacteria that reside in the soil. In this disease, bacteria introduce their genes into the plant, forcing it to produce hormones that the plant itself uses to grow. Then the plant is unable to stop its own growth, grows bloated, and develops what is called cancer. Furthermore, the disease forces the plants to produce food for the bacteria, which in turn consumes the nutrition of the plants and causes them to wither and die.
Dr. Kawaguchi, then an employee of Okayama Prefecture (now a researcher at the National Agricultural Research Organization), first took a fungus from diseased seedlings to determine the cause of the disease, and then inoculated healthy seedlings to see if they would develop the disease. At that time, he thought it was strange that some of the seedlings did not get sick when he examined several of them together. It contained disease-causing bacteria, but the disease didn't manifest itself. And he found a germ that was not causing cancer, even if there was a pathogen in it. This kind of bacteria is called antagonistic bacteria, which is a technology to counteract bacteria with bacteria, and in agriculture, it is called biocontrol bacteria or microorganism pesticides. He is in the process of moving toward practical application as such.
So, I decided to investigate how such useful bacteria suppress cancerous diseases. When the fungus was cultured, the outer fluid of the fungus had activity that killed the pathogen. We use genetics to find out what is the outer fluid, and we find the bacteria that are no longer capable of killing the pathogen one by one by preparing hundreds of damaged genetic material of the bacteria. Then we find some of them, and we look at which genes are damaged. Then we found out that the fungus was producing phage outside the body. Phages are bacterial viruses, and they were producing viruses that attach to these pathogens. It was found that when this virus was lost due to a genetic defect, the antagonistic effect was eliminated, i.e., the pathogen was killed by the virus. And what we found was not a normal phage, but a very interesting phage. Usually, phages are attached to a bacteria like a spaceship, sending genetic information to it and multiplying inside it. But, What we found was a half-baked phage that didn't have a whole body. The bag containing the genetic information was all gone, just the tube. But, the result was a powerful bactericidal effect that killed the attached bacteria by opening holes in them. Incidentally, I learned bacterial research methods from Dr. Ichinose in a neighboring laboratory. This was another valuable encounter that broadened the scope of my research.
――Have phage of that shape been around for some time?
Well, you've actually seen this type of phage in many different examples, for example, a phage is made up of several dozen genes, but it has been reported that the genes of the part corresponding to the head of the phage were cut off for some reason, leaving only the tube part. But what we have found is that the two phage gene clusters have somehow recombined, and the two halved phage genes have become attached to each other, creating a half-formed phage with no head. What has been done in this way has not yet been published in the world, and we are now trying to put it in a written paper. I think the real thrill of basic research is discovering phenomena and materials that were previously unknown. I hope to present it well to the world. When I try to make a good paper, I get a lot of requests from various people to do this and that, haha. Actually, I submitted a paper once, but it was requested in various ways, so I worked on it with students for a long time, and now that we have finally collected enough data, I am thinking of submitting it again with the data.
――How long has this study taken?
When did we start this research... I think it started around 2015, because 4 students are doing it in relay. It still takes patience. A laboratory is like a self-employed business, and it cannot operate unless it obtains money from somewhere, conducts research, produces results, and obtains money again. What I need when I get money is a track record. If I want to make a very good paper, it takes me a lot of time to write a good paper, so I plan to have a few smaller topics and write a few papers on them until I have a good paper. I am always thinking about how to release the papers, always balancing them with the management.
――It really is a very difficult job, isn't it?
Just like running a business, If we don't announce this product now, we won't make money, or we need this kind of advertising now, or I have to pay this much to hire someone. In addition, the researcher not only publishes his own papers, but also reviews those of others, applies for research funding himself, and also reviews the applications. I am also involved in school positions and committees, keeping an eye on students' presentations and progress, and various collaborative research meetings... I'm busy.
Strengths gained by starting from scratch again and again
――Then please tell us why you decided to become a researcher.
I knew I wanted to do research on living organisms, so I entered the University of Hiroshima through a number of different paths. I have 4 siblings and my family is not very rich and I was a burden on my parents, I was going to college, so I decided to study hard. The more I studied, the more interesting it became, and I gradually began to think that I would like to find a job that would make use of what I had learned, and I thought that the best place to use what I had studied would be as a researcher. Also, my parents were businessmen, and I felt that a company organization is a way of working, in which you are in charge of a part of a big job. But as a researcher, you have your own lab, and you have your own discretion in terms of management and the direction of your research, so it's a different kind of work than working for a company. So I decided to choose a job in which I had some decision-making authority.
――Have you loved living things since your early childhood?
Yes, I've been exposed to that kind of thing to some extent, and I wanted to do research on living organisms. I had only a vague idea that it would be nice to be involved in something like that. My fantasies may have grown since I could not choose biology in high school. I just never thought I would become a plant researcher at all.
――Tell us about your process of becoming a plant researcher.
When I was a university student, my department had a wide range of people doing research on various topics from micro-organisms to plants and animals, and when I chose my laboratory, I strongly felt that I wanted to study with a professor from that department (Dr. Takashi Yamada). I didn't really think too much about the theme, but I was involved in research to investigate the genetic structure of algal chromosome. I was attracted by the power and intelligence of the professor and took on a part of his research and completed it, but that was his theme, so I was thinking about what kind of research I would do in the future.
I was worried about my career path, but finally decided to go to RIKEN and start research on plants. RIKEN had one of the first professor (Dr. Kazuo Shinozaki) who started research using a model organism of dicotyledonous plant called Arabidopsis thaliana in Japan, and I decided to become a specialist of Arabidopsis thaliana. I had no idea what a plant was, and I was starting from scratch, so I started by having a technical assistant teach me how to plant seeds. My boss gave me some loose instructions while respecting my independence, and I tried a lot of things in my own way, but in the end, I was not strong enough and it did not work out very well.
One of my senior researchers gave me a mutant that would die if I planted it in the soil, and I was trying to find out the cause. Plants have immune sensors that recognize pathogen attacks, and when they're damaged, they stay switched on all the time, and it turns out that the immune response is continually triggered, so it becomes smaller and withers. But it took me about five years to get this far, and at that time I thought I was going to die, haha. I thought I was done being a researcher, haha.
――Why were you able to continue your research during such difficult times?
That was because my boss had power. I was guaranteed the first three years of research, but essentially, the important step is to produce a variety of results during those three years and move on to the next place. But in my case, three years passed without any results. I really didn't get any results, haha. So, I was hired with my boss's research funds and I was given time to get it right. During that time, I managed to publish three papers and move on to the next step, but if it had only been three years, I don't think I would have survived as a researcher anymore. I was really grateful for that.
――Are some people being closed off from becoming researchers?
Yes. After all, each of them has their own research life, and some of them go on smoothly, while others go to various research institutions and are still fixed-term researchers. There has been a lot of discussion about this fixed-term system, and I think moving to a new environment is actually a very important thing. I went from scratch to a completely different institute than what I was doing in college, and from there again, this time I went to England, so I had to start from scratch. I think it was very important to struggle, learn and improve my skills as I experienced different bosses and different themes, and I was able to expand my skills and human network there. Because I have such experiences, now that I am the boss, I can mobilize them and convey them to students, and I can advance my research with the power of those experiences. Without the compulsion to move, it is easier for people to stay in the same place. Hard to relocate if you have a family so it's not so easy to learn new things by yourself in one lab. I'm in a situation where I'm guaranteed lifetime employment, but it's hard to learn new things. So, I personally think it is important to move to a new environment on while you are young.
Recently, however, budget cuts to universities have drastically reduced the number of positions available after gaining experience through fixed-term appointments. In an overly competitive situation, researchers cannot feel at ease in a fluid environment, and the true advantages of the system will not be utilized. The future of science in Japan will not be realized without creating an environment in which the young generation that supports research is attracted to the profession and can demonstrate their abilities.
What is also important is that academia is not the only way to live as a researcher. Many PhDs, including my esteemed predecessors, are playing a very active role in their companies, and the ability of PhDs to create something from nothing is a great strength in business. The demand for such services seems to be increasing even more these days as the pace of social change is increasing. It is also important to be active in a wide range of fields, including government and politics.
Everything I've learned from my interactions with so many people has made me who I am today
――Please tell us about your life as a research in the UK.
During my first five years as a research scientist, I had initially thought that the mutants were related to environmental adaptation in plants, but eventually settled on plant immunity, and another parallel research I was doing at the time was also related to immunity. As a result, all I did was immunity work, so then I had to become a specialist in that direction from now on.
I had a connection with a Japanese man in England, Dr. Ken Shirasu, and since I had always wanted to go abroad, I was allowed to visit him. So I was given one theme, but it didn't work out at all. Then I was asked to try my hand at finding compounds, and since I had been a student of chemistry, I thought it might be a theme for me, and I started. It's a bit of a risky study, looking for something out of 10,000 compounds that may or may not be there. But for some reason, I felt like I could found it, even though I was feeling a bit energetic or foolhardy. I might have felt like I would definitely find it.
What was also good about this was that the lab had stable research funding, so they were able to easily buy a set of compounds that cost several million yen. We put compounds one by one into a 96-hole plate with 96 holes, watch the reactions, evaluate them, and quantify them, but the way I do it is to put 40 compounds in one plate, so that two plates make a set of 80 compounds. Then how many plates would it take to test 10,000 compounds, haha? Two pieces make one set of 80 pieces, so 10 sets make 800 pieces, 100 sets make 8,000 pieces, and so on, In other words, I did three rounds of about 200 pieces plus extra scale, haha. Then the plates would pile up around me and I would keep doing it day after day after day, and "It’s bad!" "Are you okay?" Everyone was saying to me that, haha. I've been doing this kind of thing in England for a long time.
――I see. So the base of a researcher was created when you were a postdoctoral fellow.
In my case, yes. I had a number of research colleagues in the lab, each working on a different topic. I saw how they were proceeding and what kind of results they were getting, and we had discussions together, and I learned how to proceed with the theme in a pseudo way. I learned how to clear the barriers by asking each other for advice when we got stuck.
At the time of the first RIKEN, there were more than ten researchers in my own laboratory alone, and the debriefing sessions were held jointly with the boss's partner laboratory, so I had a lot of opportunities to learn. I was able to learn from the entire research institute in the UK because the entire organization was full of researchers involved in plant immunity and pathology. After that, I transferred to follow Dr.Ken to the Yokohama Institute of Physical and Chemical Research (Yokohama RIKEN), which was a plant research institute, so I was able to gain a broad perspective on plant science and a network of contacts. All of these things make me who I am. I still consult with the people from that time, and I still keep in touch with Mr. Ken through research, and we just had a discussion last night, haha.
To play an active role in a society where both men and women can shine
――Thank you very much. You are now an associate professor with a variety of experiences. What is the most important thing for you when teaching students?
I think what we learn through our research activities is "how to approach the unknown. When you go out into the world in the future, you will be given various missions, but for those things that you don't know how to do, you have to do research first. From there, we need to determine the direction of the project, build up concrete ideas on how to solve the problem, and then implement the scheme to achieve the results. The idea is to have students learn about these processes while using one research theme as a subject. Since they will not be doing the same kind of research in the future, I would like them to be aware that this is just one example, and I would like them to learn how to set a theme and approach it. In addition, we aim to provide guidance so that students can acquire the ability to prepare documents, conduct research, and make presentations, which will be useful when they actually go out into the world. Of course, I am most happy when I can share the joy of discovery through research activities.
――Come to think of it, there are more and more female students in the agriculture department these days.
That is right. In the Faculty of Agriculture, about half or more of the students are women. I think it is very important for women to play an active role in society, for example, the number of female professors should really more increase. Nowadays, more and more places are actively hiring women through various schemes such as woman tenure track, etc. However, it is also true that there are some voices from the male side that say it is reverse discrimination. As mentioned earlier, opportunities for recruitment themselves are dwindling, so it is not surprising that the parties involved feel this way. First, the employer must eliminate unconscious bias ( the Japan inter-society liaison association committee for promoting equal participation of men and women in science and engineering: https://www.djrenrakukai.org/unconsciousbias/index.html) and I hope that the decision will be made fairly on that basis. I think that people who have spent time abroad, including myself, where gender equality is more advanced, often feel that the all-male situation is a bad situation and that such a situation should be flat. Perhaps it is because I was a minority overseas and experienced discrimination, but when I hear the voices of absurdity felt by Japanese females, I honestly think, "Oh, this world is not good. Since half of the students are female, it is easier to ask for advice if you study in an environment where there are half of the female professors, and you can imagine yourself being active in society as a role model. I think that is the natural state of things, and I personally hope that it will become more and more like that.
Environmentally friendly forms of agriculture will become even more important in the future
――How is Research Professor Noutoshi's research approaching the achievement of the SDGs?
In the past, agriculture has been maintained using fungicidal and insecticidal pesticides, but now there is a trend toward replacing these chemicals with alternatives, if possible, in order to reduce the burden on living organisms and the earth. It just so happens that I have been searching for agents that strengthen plant immunity and suppress disease, and I believe that if I can implement such agents that work on the plant side in society, I can reduce the amount of fungicides and lower the load. I have been searching for such agents in Okayama, and my research is aimed at the practical application of those seeds. I am not sure how far into the future this will be, but I would like to contribute to the SDGs in the form of a university-supplied technology for immune-enhancing agents.
――The world's food supply is going to become more and more scarce, isn't it?
Yes, it is. It is estimated that as the population of the earth grows to 10 billion people, we will run out of food. The major problem is how to solve this problem. On average, about 16% of the original crop is lost each year to disease. Reducing that percentage as much as possible will not only increase food production, but also contribute to the income of individual farmers and the country's economy, and If we are going to increase the amount of food harvested, it will be important to secure it in an environmentally friendly manner, and I think this form of agriculture will become increasingly important in the future.
――Thank you, Research Professor Noutoshi , for sharing so much with us!
Noutoshi Plant Resistance Inducer Development Research Group