Plants protect themselves from environmental hazards like insects, drought and heat by producing salicylic acid, also known as aspirin. A new understanding of this process may help plants survive increasing stress caused by climate change.
UC Riverside scientists recently published a seminal paper in the journal Science Advances reporting how plants regulate the production of salicylic acid. The researchers studied a model plant called Arabidopsis, but they hope to apply their understanding of stress responses in the cells of this plant to many other kinds of plants, including those grown for food.
“We’d like to be able to use the gained knowledge to improve crop resistance,” said Jin-Zheng Wang, UCR plant geneticist and co-first author on the new study. “That will be crucial for the food supply in our increasingly hot, bright world.”
Environmental stresses result in the formation of reactive oxygen species or ROS in all living organisms. Without sunscreen on a sunny day, human skin produces ROS, which causes freckles and burns. High levels of ROS in plants are lethal.
As with many substances, the poison is in the amount. At low levels, ROS have an important function in plant cells. “At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones such as salicylic acid,” Wang said. “ROS are a double-edged sword.”
The research team discovered that heat, unabated sunshine, or drought cause the sugar-making apparatus in plant cells to generate an initial alarm molecule known as MEcPP.
Going forward, the researchers want to learn more about MEcPP, which is also produced in organisms such as bacteria and malaria parasites. Accumulation of MEcPP in plants triggers the production of salicylic acid, which in turn begins a chain of protective actions in the cells.
“It’s like plants use a painkiller for aches and pains, just like we do,” said Wilhelmina van de Ven, UCR plant biologist and co-first study author.
The acid protects plants’ chloroplasts, which are the site of photosynthesis, a process of using light to convert water and carbon dioxide into sugars for energy.
“Because salicylic acid helps plants withstand stresses becoming more prevalent with climate change, being able to increase plants’ ability to produce it represents a step forward in challenging the impacts of climate change on everyday life,” said Katayoon Dehesh, senior paper author and UCR distinguished professor of molecular biochemistry.
“Those impacts go beyond our food. Plants clean our air by sequestering carbon dioxide, offer us shade, and provide habitat for numerous animals. The benefits of boosting their survival are exponential,” she said.
Black soldier flies never eat as adults, so they must binge-eat while they are still larvae (shown). ... [+]Getty
The frontier of the agriculture industry is about to take a big step closer to going mainstream. Chicago-based food processing company Archer Daniels Midland ADM-1.1% (ADM) and InnovaFeed, a French firm that makes insect protein for animal feed, plan to begin building what will be the world’s largest insect protein facility in 2021 in the city of Decatur in central Illinois.
The partnership between ADM, a $28 billion giant, and the startup InnovaFeed amounts to a vote of confidence in a nascent industry that could one day play a key role in the global agriculture sector.
“I’m in awe. If they can pull this off, it will be magnificent,” said Jeffrey Tomberlin, a professor and entomologist at Texas A&M University who has done pioneering research on insect protein. “This facility will be several times bigger than anything else in the world,” Tomberlin said.
ADM and InnovaFeed plan to grow and harvest billions of an extraordinary insect called black soldier fly, whose larvae consume prodigious quantities of organic material and convert it into nutrient-rich protein that can then be sold as animal feed. ADM and InnovaFeed aim to produce up to 60,000 metric tons of animal feed protein per year, plus 20,000 metric tons of oils for poultry and swine rations and 400,000 tons of fertilizer.
Black soldier fly larvae will eat just about anything organic — including non-compostable food waste bound for landfills — and produce hundreds of times more protein per acre than traditional animal feed sources. The new plant will give ADM and InnovaFeed a foothold in the burgeoning market for sustainably sourced food at a time when consumers’ environmental awareness is growing.
The plant would be a major step toward mainstreaming the insect protein industry, which aims to feed farm animals and aquaculture not corn, soybeans or fishmeal — common types of animal feed — but instead black soldier fly larvae and other grubs.
If widely scaled-up, this would mean vastly reducing the carbon footprint and land requirements of farm animals, especially those raised for slaughter. For every kilogram of meat they produce, cows and sheep require around eight kilograms of grains, pigs require about four kilograms and chickens need 1.6 kilograms, according to one estimate. Growing that much grain requires intensive use of land and water.
The process for efficiently cultivating black soldier flies wasn’t well understood until the early 2000s — a big reason why the insect protein industry today remains small, consisting almost entirely of startups, including many in Europe, according to Tomberlin, the Texas A&M professor. InnovaFeed, itself only a few years old, runs the current world’s largest facility, in Nesle, France. The new Decatur facility will produce around four times as much animal feed per year.
Early backers see great potential as demand for sustainably sourced food continues to grow. More than half of U.S. consumers say they want sustainable food, according to a 2019 survey by the International Food Information Council, a nonprofit. Three out of five people in the U.K. are willing to pay more for environmentally friendly food options, according to a survey of 1,000 people by professional services firm GHD released in November.
The success of plant-based meat companies this year, such as Impossible Foods, has raised hopes of shrinking the agriculture sector’s carbon footprint: the food industry is responsible for one-quarter of global greenhouse gas emissions.
The black soldier flies at the new facility, which will be run by InnovaFeed, will gorge themselves on various corn products that ADM already produces at its Decatur facilities. Normally, these corn products would undergo several rounds of additional processing before finally being transported to an end customer, explained Sapna Sanders, InnovaFeed’s Project Director for North America, in an interview.
“We’re able to avoid all those energy-intensive steps,” Sanders said.
The arrangement suits both. ADM gets to avoid the expense and hassle of further processing its corn products. InnovaFeed gets to produce and sell its animal feed, oils and fertilizer to a range of customers. One of its contracts is with the food and drink behemoth Cargill, the second-largest private company in America.
In the future, black soldier fly larvae inside commercial facilities might be doing even more environmental heavy lifting — by eating up the mountains of food scraps and other human food leftovers otherwise headed for landfills.
Roughly one-third of all the food produced in the world for human consumption each year, 1.3 billion tons, is lost or wasted, according to the U.N. Much of that ends up in landfills, where it can’t naturally biodegrade and ends up belching methane, a greenhouse gas dozens of times stronger than CO2.
Part of the reason so much food winds up in landfills is that there aren’t any convenient alternatives, especially for waste that isn’t compostable. But black soldier flies would be happy to eat up all this landfill-bound waste: researchers have found they gladly eat even foods that can’t be composted. (They appear to be uninterested in hair and bones, however.)
Bringing down the costs
The biggest obstacle to scaling the insect protein industry up further is cost. Insect protein is still more expensive as an animal feed product than, for example, fishmeal, or the parts of fish caught by commercial fishing companies that are not consumed by humans (such as offal or bones). Tomberlin has estimated that it will take five or so more years for insect protein to be cost-competitive with traditional animal feed sources, although the industry is still too young to know how far and quickly costs will fall.
The U.S. may not be the first to get there. Compared to Europe, the U.S. government has shown relatively little interest in helping the nascent industry get a leg up, Tomberlin said. Yet even more than Europe, China appears most interested in getting the insect protein industry to commercial scale, he said. It already has some of the largest and most efficient black soldier fly facilities in the world and is intensively innovating, according to Tomberlin.
Nevertheless, that one of America’s largest food companies sees commercial value in insect protein is perhaps a sign that a widespread role for it at the heart of the agriculture sector is perhaps not too far away.
Correction: An earlier photo that accompanied this story pictured another type of larvae, not black soldier fly larvae, as captioned.