November 17, 2016

Tapestry of Hope


Sweat sneaks beneath Kasia’s sunglasses as she tiptoes around the carefully organized research plots, orchestrated using GPS technology. The tiny plants reach up to grasp the sun, creating a mosaic of greens and yellows as they grow and mature, a tapestry of hope for the researchers who have cared and cultivated them.

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The scientists have spent most of their summer in this one-acre field at the University of Illinois South Farms. They water the plants using a variety of methods, from lugging heavy watering cans to inventing new systems for irrigation.  They hand pick worms and grasshoppers off the plants and study the leaves for discoloration, wilting, and other signs of disease. Their work and devotion shows in their summer tans, and sunburns—despite the liberal application of sunscreen—and in the muscles they developed from carrying heavy equipment to and from the field. “The equipment looks quite innocent, but when you carry it with two batteries, it’s not so innocent anymore,” said Katarzyna “Kasia” Glowacka, a postdoctoral researcher at the University of Illinois. “I have always joked that they are heavier now than in the beginning because of the data inside.”

More than three years of sweat, tears, and countless hours of work and research have been poured into the little sprouts.

These plants, only a few weeks old, are part of Realizing Increased Photosynthetic Efficiency (RIPE), an international research project with the aim of ensuring food security for millions of people, especially those in Sub-Saharan Africa and Southeast Asia. The goal of this $25-million research project is to help increase the yields of crops—like rice and cassava—that these families already like and know how to grow. More farmers will produce more food to feed their families and sell for disposable income, increasing their access to medicine, education, and opportunities for the future.

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Sitting in the hot summer sun in the middle of a field, these plants frequently receive more light energy than they can use for photosynthesis--the process of turning light and carbon dioxide into energy for the plant. If the plants do not use this extra energy, it can cause damage, much like the researchers’ sunburns. Unlike people or animals, plants cannot go find shelter or shade, and even if they could, they need the light for photosynthesis. Fortunately, Mother Nature has given plants a way to deal with this: by releasing some of that extra energy as heat in a process called photoprotection. This process allows plants to soak up all the energy they need to produce sugars at maximum capacity, but prevents damage to the plants.

However, even on the sunniest days, their leaves are occasionally shaded by clouds or higher leaves as the wind blows, making the available light less intense. It takes time—from minutes up to hours—for the plant to switch between dissipating extra light energy to taking up all it can. During this time, the plant is no longer photosynthesizing at 100%, losing some of the potential energy it needs to achieve its highest photosynthetic rate and full yield potential.

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Caption: University of Illinois postdoctoral researcher Johannes Kromdijk (lower left) analyzes the photosynthetic efficiency of the plants.

This patchwork of plants, now at the mercy of pests, disease, and the weather, is the culmination of three years of research. RIPE has engineered these plants to photosynthesize more efficiently, enabling them to recover more quickly in fluctuating light conditions. Each plant now has a few extra minutes every hour, every day, to absorb light at full capacity.

These plants have had to overcome many challenges before they even get to the field trials, including the restrictions and regulations that go along with an international research project. 

The first challenge is to determine which genes need to be modified. This question is answered with simulations: researchers plug in genetic changes, and computer model tells them how those changes will impact the plant. Once they identify several promising changes, they must overcome the next challenge: transferring the most promising changes from the computer model (“in silico”) into the genome of actual plants (“in vivo”). If the plants succeed in the lab, they are eventually transplanted and tested in the greenhouse. If the greenhouse data is also encouraging, they are tested in the field—where light, rainfall and other factors are unpredictable. The field is where they confirm that these changes are beneficial and viable; if they cannot, they figure out what went wrong and start over the next year.

First, they test the computer model’s predictions in tobacco, a model plant that is relatively easy to engineer and grow. Once they prove a method works in this plant, they will try transferring the method to staple food crops that are much more difficult and time consuming to engineer and grow. Glowacka and postdoctoral researcher Johannes Kromdijk, who both led RIPE’s photoprotection work, have worked together for three years preparing their tobacco plants for this field trial. These plants represent years of photosynthesis research, including critical work by principal investigators Stephen Long, Gutgsell Endowed Professor of Plant Biology and Crop Science, and University of California, Berkeley researcher Krishna Niyogi—an expert on the molecular processes underlying photoprotection.

Each year, they learn something new about how to grow their plants and conduct their research. Tobacco is not a plant that is usually grown in Illinois. Field research requires some trial and error to learn how to best grow the plants and conduct the experiment. In addition to these complications, there was significant flooding in the research site during their second year, which had a devastating effect on the plants and the data.

As a result, they learned, and it made this year’s experiment even better. They added new irrigation systems, they dug trenches, and they surrounded each experimental plot with regular tobacco plants to protect the experimental plants from pests and disease.

Caption: Irrigation lines snake through the tobacco plants in the field trials. 

Tobacco has a relatively short growing season, with only a two-week window for researchers to measure the plants and collect data. “When you have those two weeks, and you have the very precious experiment in the field, it’s crazy how often you check the weather,” said Glowacka. “You wake up to the wind and rain against your windows, and you say, ‘Oh, it’s raining, it’s cool,’ and then your second thought is: ‘How are my plants in the field?!’”

Data collection can be a strenuous and extensive task. The scientists lug heavy equipment out to the field and measure the photosynthetic rates of each plant. This means finding a developed leaf of the right size, and making sure there is the right amount of sunlight. There is plenty of waiting for the perfect conditions, followed by a flurry of activity as they try to get everything done in conditions that will give them the most accurate results.

Field season is more than just worrying about the weather, picking off bugs, and getting burned. If one group has malfunctioning equipment or needs more people to collect their data, another group will happily step in to help. There’s a certain camaraderie between the scientists: they work together, they wait patiently for the perfect conditions together, they swap stories, compare who has the best hats and the worst t-shirts. They have “good conversations” and “silly talks,” which creates a culture of community, working together to solve problems.

And at the end of it all is harvesting day, the day all the plants are taken up, bereaved of each individual leaf, measured piece by piece for their biomass, and incinerated to prevent any possible contamination. For Glowacka, this symbolizes the end of the experiment. In fact, it is her favorite day, and her excitement of completing the experiment is equal only to the first day at the start of the experiment. She laughs, “It’s like grandchildren: when they visit you, you are so happy when you open the door, and you’re so happy when you close the door. It’s like, equal happiness!”

After all the harvesting and the measuring, there is still work to be done. All the data they collected and the hand written notes about heights, weights, and biomass needs to be logged in an excel document and analyzed with sophisticated statistics. Then the data needs to be interpreted so they can understand the results of the experiment.

While others may head to the bar, Kromdijk and Glowacka head back to the lab. They can’t wait to upload their data and finish the statistical analyses. “That is how we are,” Glowacka said. “It was like, yes, we have it, we have it, we have it! We were so excited because we want to submit this awesome paper that will change the world forever—at least our world.”

Since then, Glowacka and Kromdijk have submitted their results, and had their research paper accepted by the prominent journal, Science. With the 15% increase in yields in this year’s field trials, these scientists are well on their way to making RIPE’s altruistic goals a reality. With these extra minutes—in millions of plants in thousands of fields across the world—we can capture more of the sun’s energy to produce more food for more people.

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Kasia’s day in the field starts at 8 a.m. and can last into the night. On days that stretch past sunset, the grasshoppers of the day slowly fade, and the lightning bugs begin to spark. First one. Then another. Soon, these tiny floating lights have taken over the night, and the fields are dancing with a dim yellow glow, creating a tapestry of light against the darkness. “It is really like magic—it is magic.”


Source: Katarzyna Glowacka

Writer: Rachael Geiger 

Editor: Claire Benjamin 

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