Wired In: Carl Bernacchi


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Each week, staff writer Paul Wood talks with a tech pioneer. This week, meet Professor CARL BERNACCHI, a USDA scientist with the Global Change and Photosynthesis Research Unit at the University of Illinois. He studies the effects of climate change, focusing on crop species important to the Midwest.

Where did you get your degrees, and what made you decide on this line of research?

I earned my master's degree in biology from Bradley University in Peoria, and my doctorate in plant biology with a focus in photosynthesis from the UI. I have always considered photosynthesis a fascinating process, and when I had a chance to work in a top lab focusing on photosynthesis research and climate change, I eagerly accepted the challenge. After earning my doctorate, I broadened my research portfolio to include more than just photosynthesis, but remained highly focused on two major challenges facing society: climate change and agricultural production.

News that rising temperatures may safeguard crop nutrition as our climate changes sounds like the first good news on that subject in a while.

That higher temperatures lead to improved nutrition may suggest that warming is good. But this research shows that there is a penalty associated with these warmer temperatures, namely that yields go down. This is the opposite effect of rising carbon dioxide, which causes yields to go up but the quality to go down. The result further shows that when rising carbon dioxide and warmer temperatures are combined, they are offsetting — there is no loss in quality, but there also is no gain in quantity.

How did you get the idea for this study?

This study started through a casual conversation at a conference that resulted in four scientists, who focus on different topics, realizing the potential to blend our expertise to address an important scientific question. Dr. Köhler, then a researcher here, and I had conducted a field experiment to address the impacts of high temperatures and elevated carbon dioxide on soybean photosynthesis and growth. A collaborator, Dr. Steven Huber, was keenly interested in understanding how these treatments impacted the protein and lipid composition of the soybean yields. In a casual conversation with Dr. Ivan Baxter at a conference, he expressed a strong interest in analyzing the yields for macro- and micro-nutrients. The result is a serendipitous outcome that relied on the existing experiment, the foresight to archive soybean yields, and a chance conversation that brought together four scientists who each provided expertise in different research areas to answer an important question. The resulting research paper is an ideal example of a truly collaborative endeavor.

Why would hotter temperatures offset the negative effects of higher carbon-dioxide levels on seed quality?

That is an excellent question. At this point, we do not know, but we are starting to focus on how best to answer that question. A current hypothesis is that both carbon dioxide and temperature impact the amount of water moving through a plant — elevated carbon dioxide levels usually result in less water moving through the plant and higher temperatures usually result in more water moving through. Many of the nutrients, but not all, move from the roots and up the plant with water, then concentrate in the plant tissues. The movement of water and the nutritional quality of the yield seem to correlate, but without direct evidence, this is only a hypothesis. We are in the process of designing experiments that can test this hypothesis. One way is to alter humidity around the plants growing in the field. Less water moves through the plant with high humidity, which allows us to test whether data supports this hypothesis.

Your team tested the soybeans in real-world field conditions at the Soybean Free-Air Concentration Experiment, an agricultural research facility at Illinois equipped to artificially increase carbon dioxide and temperature to futuristic levels. Do outside conditions play a role? If so, were these two years fairly consistent with usual conditions?

Outside conditions always play a role in field work. To some extent, we were fortunate that neither of the growing seasons experienced significant extremes in growing conditions. On the other hand, when extreme conditions occur, we stand to gain new insights. Therefore, we try to run experiments for many years to better understand responses under both "typical" and "atypical" growing conditions.

Can you do these studies around the year?

We do not. A strength of our research is that our experiments are conducted under real-world conditions that are typical of traditional agricultural practices. Therefore, we are limited to the same growing as farmers in this region. We plant, manage and cultivate these experiments just as farmers would, except for raising the temperature or increasing the carbon-dioxide concentrations experienced by the plants throughout the growing season. During the growing season, we spend long days, and sometimes nights, collecting as much data as possible. During the late fall and winter, we perform laboratory analyses on the plant tissue we collected, analyze and interpret the data, and write papers to inform the scientific community and the public of our findings. Then in the spring, we prepare for the next round of experiments.

It sounds like a double-edged sword — rising temperatures may actually benefit nutrition, but at the expense of lower yields. When you weigh both factors, is this a plus or minus for humans and farm animals?

That is a difficult question, and I'm not sure that I have a good answer. Certainly, we want agricultural fields to produce more yield, but we also want that yield to be high quality. It may be fortunate that these two dominant global changes — a warming planet with rising carbon dioxide — offset each other, but the ideal would be higher yields with higher nutritional quality. As researchers, we need to seek a better understanding of why plants behave the way that they do, and then look for opportunities to improve crops so that we don't have an "either/or" situation when it comes to yield quality versus yield quantity.

In soybeans, elevated carbon-dioxide levels decreased the amount of iron and zinc in the seed by about 8 to 9 percent, but increased temperatures had the opposite effect. How important are these metals in human nutrition?

Iron and zinc are important for many aspects of our overall health. For example, iron is involved in oxygen transport in blood, respiration, and DNA synthesis, and zinc is important for immune defense, cell growth, and healing. But the importance of these nutrients extends well beyond what I've listed here. Estimates suggest that around 2 billion of the over 7 billion people on the planet suffer from deficiencies in these nutrients.

You were co-principal investigator at the Donald Danforth Plant Science Center USDA National Institute of Food and Agriculture. Have you been in partnership for a long time?

The Danforth Center is a world-class research facility, and I have been aware of great research coming from that institution. This research center has also worked closely with researchers from the USDA and the UI for many years. This is, however, the first time that I, personally, worked with a scientist from the Danforth Center. I do, however, foresee continuing this partnership, as Ivan and I have already outlined the next steps in this research.

Do you have plans in place for your experiments to figure out the mechanisms responsible for this effect?

Absolutely. Science is a never-ending pursuit to understand our world, and interesting results, such as those observed in this study, leads to more questions. However, this pursuit is not without its challenges. We have some ideas about where to take this research, particularly regarding the role of water movement and nutrition. This coming growing season, I will be testing new prototype field instruments that can control humidity in the field, as mentioned above. If successful, the next step will be to scale this to an experimental level, which includes replicating the experiment, purchasing equipment, hiring research staff to assist with the experiments, and securing funding to cover the expenses associated with this research.

What's your best advice for someone who's starting up in research?

My best advice is to keep all options open and find a great mentor. My career path was circuitous but ultimately landed me in a job I love. Throughout the entire process from undergraduate to graduate to post-doc to staff scientist to running my own research laboratory, I focused on seeking opportunities when presented and making the most of the opportunities I had. I also have mentors that, even after 20 years, I still look to for advice in everything from science to administration to my personal life.

Did you ever make any mistakes that you learned from in your early years?

I still make mistakes, and the goal is to identify mistakes early and to learn from them. In one case, a mistake led to a whole new line of research in my laboratory. Years ago, when I built the first prototype heating system used in this experiment, I had made a mathematical error in the program for the temperature control. When I first turned on the system, and saw it warming the plants, I decided to let the system run while I ate lunch. Right after lunch I checked the status of the system, and instead of warming the plants by 3 degrees Celsius, they were warmed to 12 degrees Celsius. Fortunately, this was a prototype and not a real experiment. But realizing the full potential of the heating system led me to design heatwave experiments using the same technology, which ultimately led to new understanding of crop responses to short-term, high-intensity warming typical of heatwaves.


Do you have interests in social media? I am involved in social media both for personal and professional reasons. I find Twitter is a great way to promote my science (@CBernacchi) and learn from others. Distilling a research paper into 140 characters is a challenge, but if done right, it can really lead to more people reading the full paper. My Facebook profile is limited to close friends, family and acquaintances.

On Twitter I follow ... My Twitter feed is dominated by scientists and colleagues. But there are also a healthy number of comedians that I follow. An occasional unexpected joke in my Twitter feed adds humor to the day.

Book or Kindle? What are you reading right now? I primarily read on my tablet even though I really prefer books. I suppose buying books requires visiting a store, so I opt for what's convenient. Outside of work material, I'm finishing up the Matthew Scudder book series by Lawrence Block. I also have "Swimming and Diving Rules Books" installed that I check frequently when I volunteer as a swim official for high school, NCAA, or YMCA swim meets.

Do you have any wearable electronics? I don't tend to accessorize, but I recently got an Apple Watch. I've had it for about a month, but I'm not sure if I like it yet. It distracts me quite a bit and is not very accurate at counting swimming laps.


Paul Wood is a reporter at The News-Gazette. His email is pwood@news-gazette.com, and you can follow him on Twitter (@pvawood).