It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
The winners and losers of Trump’s first tariff war strongly suggest that bankruptcies and farm consolidation could surge during his second term, with major corporations best placed to benefit from his polices at the expense of independent farmers.
New analysis by the non-profit research advocacy group Food and Water Watch (FWW), shared exclusively with the Guardian, shows that Trump’s first-term tariffs were particularly devastating for farmers in the Maga rural heartlands.
Numbers of farms fell at the highest rate in two decades with the smallest operations (one to nine acres) hardest hit, declining by 14% between 2017 and 2022. Meanwhile, the number of farms earning $2.5m to $5m more than doubled.
Losses from the first-term trade war were mostly concentrated in the midwest due to the region’s focus on export commodities such as corn, soy and livestock that are heavily reliant on China. States with more diverse agricultural sectors such as California and Florida experienced lower rates of insolvency and export declines than in previous years, suggesting the trade war played a role, according to Trump’s Last Tariff Tantrum: A Warning.
The breakdown in closures suggests that Trump’s $28bn tariff bailout package in 2018-19 disproportionately benefited mega-farms while smaller-scale farms and minority farmers were left behind.
The top tenth of recipients received 54% of all taxpayer bailout funds. The top 1% received on average $183,331 while the bottom 80% got less than $5,000 each, according to previous analysis.
The number of Black farmers fell by 8% between 2017 and 2022, while white farmer numbers declined by less than 1%.
Workers on a farm n Homestead, Florida, on 25 April. Photograph: Chandan Khanna/AFP/Getty Images
“President Trump’s first-term trade war hurt independent farmers and benefited corporations, offering a warning of what is to come without a plan to help farmers adjust,” said Ben Murray, senior researcher at FWW.
“Trump’s latest slap-dash announcements will likely further undermine US farmers while benefiting multinationals who can easily shift production abroad to avoid high tariffs. Farmers’ livelihoods should not be used as a foreign policy bargaining chip. Chaotic tariff tantrums are no way to run US farm policy.”
The first 100 days of Trump 2.0 have led to turmoil and uncertainty for consumers, producers and the markets, amid an extraordinary mix of threats, confusing U-turns and retaliatory tariffs from trading partners.
Trump’s second trade war could prove even more damaging for US farmers and rural communities, as it comes on top of dismantling of agencies, funds and Biden-era policies to help farmers adapt to climate shocks, tackle racist inequalities and strengthen regional food markets. By the end of April, more than $6bn of promised federal funds had been frozen or terminated, according to the National Sustainable Agriculture Association’s tracker.
Last week, the agriculture secretary, Brooke Rollins, played down the likely harm to Trump’s farmer base, but said the administration was preparing a contingency bailout plan if farmers are hurt by escalating trade wars. “We are working on that. We are preparing for it. We don’t believe it will be necessary,” Rollins told Fox News. “We are out across the world, right now, opening up new markets.”
US farm policy has long incentivized large-scale monocropping of export commodities such as wheat, corn, soy, sorghum, rice, cotton – and industrial animal farming – rather than production for domestic consumption. This globalized agricultural system favors large and corporate-owned operations, while undermining small, diversified farms and regional food systems. It is a system inextricably tied to global commodity markets, and therefore extremely vulnerable to trade wars.
The 2018-19 bailout payments were set up in a way that, inadvertently perhaps, “subsidized, encouraged and promoted” the loss of smaller and mid-size farms to the benefit of mega-farms – in large part because the tariffs were implemented without a coherent plan to reform US farm policy and help farmers transition to domestic markets.
The number of large farms – those earning more than $500,000 – grew by 18% between 2017 and 2022. “The taxpayers are essentially being asked to subsidize farm consolidation,” the Environmental Working Group said at the time.
Trump’s first-term tariffs hit soybean farmers, who are highly dependent on China, hardest, with exports slumping 74% in 2018 from the previous year. The number of soybean farms fell almost 11% between 2017 and 2022 – a significant turn of fortune given the 9% rise over the previous decade. In fact, the only winners after Trump’s trade war were big farms, those harvesting at least 1,000 acres of soybeans, the FWW analysis found.
The 2018/19 tariff bailout package was also used to facilitate contracts and commodity purchases. A significant share went to the billion-dollar corporations which already have a stranglehold on the US food system, and rural communities.
Arkansas-headquartered Tyson Foods received almost $29m in federal contracts and purchases between August 2018 and July 2019, while Brazil-based JBS secured nearly $78m. JBS used its market power to undercut competition, winning over a quarter of the total $300m in taxpayer dollars allocated towards federal pork purchases, according to FWW.
The two multinationals currently control 40% to 50% of the US beef market, 45% of poultry and, along with two other corporations, 70% of the pork market.
Things could be even worse under Trump 2.0, with the president no longer seeming concerned by the markets or the polls.
John Boyd Jr, a fourth-generation Black farmer, has been unable to secure a farm operating loan since Trump’s tariffs sent commodity prices tumbling. USDA field offices that help farmers apply for credit and government subsidies, which Black, Native and other minority farmers were already disproportionately denied, are being closed in the name of efficiency.
Farmer John Boyd Jr during a break from bailing hay at his farm in Boydton, Virginia, on 27 May 2021. Photograph: Steve Helber/AP
“This administration is putting the heads of Black farmers on the chopping block and ridiculing us in public with no oversight and no pushback from Congress,” said Boyd, president and founder of the National Black Farmers Association, who farms soy, wheat, corn and beef in Virginia. “Trump’s tariffs are a recipe for complete disaster, and this time his voters in red states will also get punched in the face.”
Trump 2.0 tariffs against China are higher and broader, and also target scores of other agricultural trading partners. China is better prepared, having diversified its import markets to Brazil and other Latin American countries since Trump’s first trade war, while US domestic farm policy has barely changed.
“The administration seems completely blind to the harm that was done previously, and in many ways what’s happening now is already worse … The concern is that trades are stalled and nothing’s really flowing,” said Ben Lilliston, director of rural strategies and climate change at the Institute for Agriculture and Trade Policy.
In late April, China cancelled a 12,000-tonne order of US pork – the largest cancellation since the start of the Covid pandemic, suggesting Trump’s tariff war is already sabotaging trade.
“The lesson from last time is we didn’t get the money to the right farmers. But the longer-term lesson is that the US lost credibility in trade. US Secretary Rollins is going overseas to try to open up export markets but they seem to be in deep denial right now about the harm that’s already been done to these relationships,” Lilliston said.
A USDA spokesperson said: “President Trump is putting farmers first and will ensure our farmers are treated fairly by our trading partners. The administration has not determined whether a farmer support program will be needed at this time. Should a program need to be implemented in the future, the department’s goal will always be to benefit farms of all sizes.”
JBS, Tyson and the American Farm Bureau Federation, a lobby group, have been contacted for comment.
Tuesday, April 29, 2025
Sugar signalling applications could boost wheat yields by up to 12%
Long term field study confirms effectiveness of new technology
Oxford & Harpenden, UK. 29 April 2025. Enhancing wheat plants’ sugar signalling ability could deliver increased yields of up to 12%, according to researchers from Rothamsted, Oxford University and the Rosalind Franklin Institute in a study published today in the journal Nature Biotechnology. That is an order of magnitude greater than annual yield increases currently being achieved through breeding.
The effect was achieved by applying a Trehalose 6-phosphate (T6P) pre-signalling molecule to the plants. T6P is a signalling molecule that regulates the plant equivalent of “blood sugar.” It is a major regulator of metabolism, growth and development including activating the pathway for the synthesis of starch, the world’s most significant food carbohydrate.
The link was discovered during research started at Rothamsted in 2006. Now a four year-long field study using plots at CIMMYT, Mexico and INTA, Argentina has confirmed that the new technology could deliver major yield improvements.
Wheat has complex genetics and targeting genetic bottlenecks in germplasm makes improvement through breeding far from straightforward. A chemical application of T6P acts as a switch for starch biosynthesis in grain, which forms the basis of wheat yields. This in turn this stimulates photosynthesis in the flag leaf, due to greater demand for carbon building blocks for grain filling.
Experiments in controlled environments looked promising, but this new study shows the application can deliver in field conditions. Not only did T6P increase wheat yields in each of the 4 years in the trials in Argentina and in an additional year at CIMMYT in Mexico, but it did so irrespective of rainfall, the major uncontrolled abiotic factor that limits crop yields globally.
It may even be possible to reduce fertiliser applications as T6P treatment activates genes for amino acid and protein synthesis in grain as well as the pathway for starch synthesis. This is important because a major issue in new higher-yielding wheat varieties is dilution of protein content requiring increased fertiliser to maintain quality for bread making.
“The path from discovery to translation has taken 25 years,” says Rothamsted’s Dr Matthew Paul who led the research with Professor Ben Davis at The Rosalind Franklin Institute and Oxford University. “Such timeframes are not untypical in blue-skies plant research, but we do hope new technologies, such as AI and faster analytical techniques, can accelerate this process. We will need many more innovations like this to create sustainable and resilient agriculture in the coming decades. I am so grateful to my excellent people, co-workers and teams and for grants from UKRI-BBSRC which made this work possible. Getting this far has been hard work but extremely rewarding”.
Rothamsted and Oxford have created SugaROx, a spinout company, to deliver this research to farmers. Dr Cara Griffiths, lead author of the research paper and CEO of SugaROx, said, “It’s exciting to be able to take cutting-edge technology from the bench to the field. Getting this kind of impact is often difficult to translate to the field, and this work demonstrated that novel crop inputs have huge promise to enhance yield and resilience in our cropping systems, something that is particularly important in a rapidly changing climate”.
“This work provides an excellent example of a case where direct selective manipulation of key molecular structures, rather than genetics or gene editing, inside a living system is a game changer," said Professor Davis. "It has been very inspiring to design and discover this new class of ‘drug for plants’ together.”
The study ‘Membrane-permeable trehalose 6-phosphate precursor spray increases wheat yields in field trials’ will be published in Nature Biotechnology at 10:00 BST / 05:00 ET Tuesday 29 April at https://doi.org/10.1038/s41587-025-02611-1.
Professor Ben Davis leads the Molecular Perturbations Challenge at the Rosalind Franklin Institute, which aims to be able to use chemistry to engineer biology by modifying specific functional biomolecules in specific locations inside living organisms. This research could have additional real-world applications for human health in the creation of new diagnostics and therapeutics.
Rothamsted Research is the longest-running agricultural research institute in the world with a proud history of ground-breaking discoveries. Our founders, in 1843, were the pioneers of modern agriculture and, through independent science and innovation, we continue to make significant contributions to improving the sustainability of agri-food systems in the UK and internationally. Our strength lies in our gene to field approach, which combines science and strategic research, interdisciplinary teams and partnerships. Rothamsted is also home to three unique resources, open to researchers from all over the world: The Long-Term Experiments, Rothamsted Insect Survey and the North Wyke Farm Platform. We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT). https://www.rothamsted.ac.uk @Rothamsted
About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the ninth year running, and number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.
Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.
Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.
The Rosalind Franklin Institute
The Rosalind Franklin Institute is a technology institute for life science, creating innovative technologies that transform our understanding of life. Our technologies, borne out of innovation in physical sciences, create collaborations and new avenues in life science which will lead to new therapeutics and advance our understanding of human biology.
The Franklin is an independent organisation funded through the UK Research and Innovation’s Engineering and Physical Sciences Research Council (EPSRC).
Follow us on LinkedIn or bluesky @RosFrankInst or find out more at www.rfi.ac.uk.
US farmers are anxious to see how planned tariffs and retaliation will be resolved - Copyright AFP/File Mark RALSTON Beiyi SEOW
As President Donald Trump’s sweeping global tariffs took effect this weekend, US farmers hoping for a profit this year instead found themselves facing lower crop prices — and the prospect of ceding more ground in foreign markets.
“We’re already getting below break-even at the current time,” said Jim Martin, a fifth-generation Illinois farmer who grows soybeans and corn.
“We knew it was coming,” he told AFP of Trump’s tariffs. “I guess we’re anxious to see how things are going to eventually be resolved.”
The president’s 10-percent “baseline” rate on goods from most US trading partners except Mexico and Canada took effect Saturday.
And dozens of economies, including the European Union, China and India, are set to face even higher levels — tailored to each party — starting Wednesday.
With talk of retaliation, farmers, a key support base in Trump’s 2024 re-election campaign, are again in the crossfire and bracing for losses.
Prices for many US agricultural products fell alongside the stock market on Friday, following Trump’s tariff announcement and China’s pushback.
China, the third-biggest importer of American farm goods behind Canada and Mexico, is set to be hard hit, with a 34-percent US duty on its products piling on an earlier 20-percent levy.
In response, Beijing said it would place its own 34-percent tariff on American goods, stacking on previous rates of up to 15 percent on US agricultural products.
The tariffs mean businesses pay more to import US products, hurting American farmers’ competitiveness.
– Market loss –
“There is less incentive for them to purchase US soybeans. It is cheaper to get them out of Brazil by far,” said Michael Slattery, who grows corn, soybeans and wheat in the Midwest state of Wisconsin.
At least half of US soybean exports and even more of its sorghum go to China, which spent $24.7 billion on US agriculture last year, including on chicken, beef and other crops.
But the US Department of Agriculture (USDA) said China’s purchases last year dropped 15 percent from 2023 “as soybean and corn sales fell amid rising competition from South America.”
Slattery expects Chinese buyers will dial back further.
“The loss of this market is a very big deal, because it’s expensive to find other buyers,” said Christopher Barrett, a Cornell University professor whose expertise includes agricultural economics.
During Trump’s escalating tariff war in his first presidency, China was the “only target, and therefore the only country retaliating,” Barrett said.
With all trading partners now targeted, farmers will likely have a harder time finding new markets, he said.
– ‘Band-aid’ –
“More than 20 percent of farm income comes from exports, and farmers rely on imports for crucial supplies like fertilizer and specialized tools,” the American Farm Bureau Federation warned this week.
“Tariffs will drive up the cost of critical supplies, and retaliatory tariffs will make American-grown products more expensive globally,” it added.
The International Dairy Foods Association cautioned Wednesday that “broad and prolonged tariffs” on top trading partners and growing markets risk undermining billions in investments to meet global demand.
Retaliatory tariffs on the United States triggered over $27 billion in agricultural export losses from mid-2018 to late-2019, the USDA found.
While the department provided $23 billion to help farmers hit by trade disputes in 2018 and 2019, Martin in Illinois likened the bailouts to “a band-aid, a temporary fix on a long-term problem.”
“The president says it’s going to be better in the long-term so we need to decide how patient we need to be, I guess,” he added.
Martin, like other producers, hopes for more trade deals with countries beyond China.
Slattery called Trump’s policies “a major restructuring of the international order.”
He is bracing for losses this year and next.
“I’ve attempted to sell as much as I can of the soybeans and corn in advance, before Trump began to indicate the amount of tariffs he was going to charge,” he said.
Sunday, March 23, 2025
Nature’s warriors: How rice plants detect and defend against viral invaders
Peking University, March 20, 2025: A groundbreaking study led by Li Yi, professor at the School of Life Sciences, was published in Nature on March 12, titled “Perception of viral infections and initiation of antiviral defence in rice”, uncovering a molecular mechanism by which rice cells perceive viral infections and initiate antiviral response, which significantly contributes to understanding of virus-host interactions for further disease resistance breeding.
Why it matters: Viruses affecting rice, a staple food for more than half of the world population, pose persistent threats to crop production and could severely undermine global food security. Though recent discoveries have revealed how rice plants mitigate such threats by initiating immune responses against insect-borne viruses, the molecular mechanism by which plant hosts perceive viral infections and initiate defense remains elusive.
Key Findings & Methodology: The research team introduced viruses to rice plants via insect vectors, employing natural infection methods that mimic real-world agricultural conditions to provide more accurate insights into plant-virus interactions. The study uncovered a complete antiviral immune pathway that sets off the following reactions in the plant’s immune system: 1. Perception and recognition of viral coat proteins mediated by RBRL; 2. Degradation of jasmonic acid(JA) signaling pathway repressors; 3. Activation of RNA silencing core protein AGO18 expression via the jasmonic acid signaling pathway; 4. Upregulation of a synergistic defense mechanism involving AGO18-mediated RNA interference and reactive oxygen species (ROS), which strengthened the plant’s ability to fend off the virus.
Other key findings include: 1. The RING1-IBR-RING2 type ubiquitin ligase(RBRL) in rice can not only recognize the coat protein (CP) of the Rice stripe virus (RSV) but also the coat protein P2 of the Rice dwarf virus (RDV). 2. Further research indicates that the RSV CP not only induces an upregulation of RBRL expression but also activates the ubiquitin ligase activity of RBRL. This, in turn, promotes the ubiquitination and degradation of the jasmonic acid signaling pathway repressor NOVEL INTERACTOR OF JAZ 3 (NINJA3) mediated by RBRL, thereby activating the jasmonic acid signaling pathway in rice.
Significance The discovery made by Li Yi's team, combined with their previous research findings, has elucidated a core antiviral pathway in rice. This pathway encompasses the entire chain of processes from the perception of viral infection by rice cells to the activation of the antiviral immune mechanisms in rice. This research represents a milestone in plant virology and crop science, bringing researchers closer to developing a multi-target strategy for antiviral breeding of crops.
*This article is featured in PKU News' "Why It Matters" series. More from this series.
SAN DIEGO, March 23, 2025 — Dogs have many jobs but one you may not expect is identifying grapevines coated in a destructive and highly contagious fungus. Although dogs can detect serious vine infections by smell, scientists don’t know exactly what odor molecules are triggering the response. Researchers are now analyzing volatile chemicals emanating from grape leaves infected by a fungus called powdery mildew with the goal of improving training for vineyard canines.
Nayelly Rangel, a graduate student at Texas Tech University, will present the team’s results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
“Powdery mildew is one of the most contagious diseases that affects grapevine plants,” says Rangel. “It reduces plant growth, fruit quality and quantity, and it can lead to a decline in wine quality.”
The current method to identify an infection relies on humans looking for tell-tale patches of grey powder along plant leaves. But, by then, the condition is usually serious and requires large amounts of fungicide to eradicate. Past research showed that dogs can identify powdery mildew by smell. But not much is known about the chemistry of what these animals smell, or whether the plants’ odor profile changes as the infection progresses.
“Our four-legged friends don’t talk, so we’re trying to understand what they are encountering when they’re sniffing,” says Paola Prada-Tiedemann, a professor of forensic science at Texas Tech University who is leading the study. So, the researchers set out to identify which volatile organic compounds, or airborne scents, grapevine leaves give off at different stages of powdery mildew infection.
First, the team needed a technique that would keep leaf samples intact for dog training. So, they placed a leaf inside a vial and inserted a tiny absorptive fiber into the vial to pick up chemicals from the air above a leaf. From there, the researchers characterized the volatile organic compounds (VOCs) stuck to the fiber by inserting it directly into a gas chromatograph-mass spectrometer.
“Our approach is unique because we’re testing the exact location where a canine sniffs the grape leaf,” says Rangel. “So, we’re analyzing the same airspace in both scenarios, whether we’re in the chemistry lab or the canine lab.”
So far, the team has optimized their process from the VOCs emitted from healthy leaves. Initial results from comparisons of healthy and fungus-impacted grapes revealed that the baseline odors emitted from healthy leaves include more acidic odor compounds than sick ones. In fact, healthy leaves released fewer vapors over time, says Rangel, in contrast to sick leaves that expelled more VOCs as the infection grew.
Next, the researchers will analyze the chemical composition of what’s wafting off the leaves at different stages of infection. Once they’ve identified a few key molecules, they will present each one individually to the canines, measure the animals’ responses to each, and test the smallest amount needed for detection. Like how certain scents, such as vinegar’s, are strong in small amounts, the researchers think that dogs may pick up on certain VOCs more easily than others. Using those compounds for training could enable more sensitive and accurate mildew identification, especially early-stage infections.
“The ultimate goal is to move away from the visual diagnosis of mildew to odor diagnosis as the gold standard,” says Prada-Tiedemann. “Even when we can’t see it ourselves, the dog sitting next to a plant can tell you with their nose, ‘uh oh, that vine’s starting to go.’”
By “bridging the canine to chemistry,” as Prada-Tiedemann says, the team wants to find a more efficient solution for protecting grapevines from a widespread and damaging disease. After all, she adds, “We all want good wine!”
The researchers report no external funding for this work.
A Headline Science YouTube Short about this topic will be posted on Sunday, March 23. Reporters can access the video during the embargo period, and once the embargo is lifted the same URL will allow the public to access the content. Visit the ACS Spring 2025 program to learn more about this presentation, “Evaluating chemical odor profiles of Vitis vinifera: Odor profiling for pathogen identification” and other science presentations.
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The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
Note to journalists: Please report that this research was presented at a meeting of the American Chemical Society. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.
Title Evaluating chemical odor profiles of Vitis vinifera: Odor profiling for pathogen identification
Abstract Powdery mildew is a highly contagious fungal disease that can target a wide variety of plants. Though this disease is rarely fatal, it can severely weaken the plant, reduce growth and fruit yield, and increase susceptibility to other diseases. This pathogen has risen in importance to viticulturists due to its impact on vineyards economy and fruit quality. There is an increasing need to develop more precise methods of disease identification to enhance current mitigation strategies. One such method involves the use of detection dogs. Biological detection dog training must adequately reflect what canines will encounter in the field, and to do so, research must be conducted not just to optimize training methods but to also understand the target odor source composition. Therefore, the goal of this research is to identify grapevine powdery mildew specific volatile organic compounds (VOCs) through the headspace analysis of healthy and infected plant leaves using solid-phase microextraction/gas chromatography-mass spectrometry. Targeted method parameters for headspace diagnostic applications included the optimization of the SPME fiber and extraction time to determine maximum extraction efficiency. Evaluating the VOC profiles of grape leaves as the infection progresses gives insight on characteristic volatile biomarkers, which can aid in canine detection training by providing an objective volatolomic approach on pathogen identification.
Triggering parasitic plant ‘suicide’ to help
farmers
UC Riverside research explores a new way to fight devastating weeds
Parasitic weeds are ruthless freeloaders, stealing nutrients from crops and devastating harvests. But what if farmers could trick these invaders into self-destructing? Scientists at UC Riverside think they’ve found a way.
Across sub-Saharan Africa and parts of Asia, places already struggling with food insecurity, entire fields of staples like rice and sorghum can be lost to a group of insidious weeds that drain crops of their nutrients before they can grow. Farmers battle these parasites with few effective tools, but UCR researchers may be able to turn the weeds’ own biology against them.
This trick is detailed in the journal Science, and at its heart lies a class of hormones called strigolactones — unassuming chemicals that play dual roles. Internally, they help control growth and the plants’ response to stresses like insufficient water. Externally, they do something that is unusual for plant hormones.
“Most of the time, plant hormones do not radiate externally — they aren’t exuded. But these do,” said UCR plant biologist and paper co-author David Nelson. “Plants use strigolactones to attract fungi in the soil that have a beneficial relationship with plant roots.”
Unfortunately for farmers, parasitic weeds have learned to hijack the strigolactone signals, using them as an invitation to invade.
Once the weeds sense the presence of strigolactones, they germinate and latch on to a crop’s roots, draining them of essential nutrients.
“These weeds are waiting for a signal to wake up. We can give them that signal at the wrong time — when there’s no food for them — so they sprout and die,” Nelson said. “It’s like flipping their own switch against them, essentially encouraging them to commit suicide.”
To understand strigolactone production, the research team led by Yanran Li, formerly at UCR and now at UC San Diego, developed an innovative system using bacteria and yeast. By engineering E. coli and yeast cells to function like tiny chemical factories, they recreated the biological steps necessary to produce these hormones. This breakthrough allows researchers to study strigolactone synthesis in a controlled environment and potentially produce large amounts of these valuable chemicals.
The researchers also studied the enzymes responsible for producing strigolactones, identifying a metabolic branch point that may have been crucial in the evolution of these hormones from internal regulators to external signals.
“This is a powerful system for investigating plant enzymes,” Nelson said. “It enables us to characterize genes that have never been studied before and manipulate them to see how they affect the type of strigolactones being made.”
Beyond agriculture, strigolactones hold promise for medical and environmental applications. Some studies suggest they could be used as anti-cancer or anti-viral agents, and there is interest in their potential role in combating citrus greening disease, which is doing large-scale damage to citrus crops in Florida.
Scientists still have questions about whether the weed suicide strategy will work in real-world fields. “We’re testing whether we can fine-tune the chemical signal to be even more effective,” Nelson said. “If we can, this could be a game-changer for farmers battling these weeds.”
This research was supported by the NSF-funded Plants3D traineeship program, led by distinguished UCR professor and geneticist Julia Bailey-Serres. The program trains students to design original biology and engineering solutions to the projected problem of massive-scale global food insecurity.
“The program is so exciting because it helps students learn to use the most cutting-edge technologies to increase crop yields and nutritional value, while also helping themselves professionally,” Bailey-Serres said.
Artistic rendering of cellulose biosynthesis with zoomed in view. Individual cellulose chains (dark brown) are synthesized by plasma membrane-bound (purple) cellulose synthase enzyme complexes (cream) and associate into elementary fibrils (light brown) that further assemble into a microfibril network, forming the main scaffold for the cell wall.
Credit: Ehsan Faridi/ Inmywork Studio/ Chundawat, Lee and Lam Labs
In a groundbreaking study on the synthesis of cellulose – a major constituent of all plant cell walls – a team of Rutgers University-New Brunswick researchers has captured images of the microscopic process of cell-wall building continuously over 24 hours with living plant cells, providing critical insights that may lead to the development of more robust plants for increased food and lower-cost biofuels production.
The discovery, published in the journal Science Advances, reveals a dynamic process never seen before and may provide practical applications for everyday products derived from plants including enhanced textiles, biofuels, biodegradable plastics, and new medical products. The research also is expected to contribute to the fundamental knowledge – while providing a new understanding – of the formation of cell walls, the scientists said.
It represents over six years of effort and collaboration among three laboratories from differing but complementary academic disciplines at Rutgers: the School of Arts and Sciences, the School of Engineering, and the School of Environmental and Biological Sciences.
“This work is the first direct visualization of how cellulose synthesizes and self-assembles into a dense fibril network on a plant cell surface, since Robert Hook’s first microscopic observation of cell walls in 1667,” said Sang-Hyuk Lee, an associate professor in the Department of Physics and Astronomy and an author of the study. “This study also provides entirely new insights into how simple, basic physical mechanisms such as diffusion and self-organization may lead to the formation of complex cellulose networks in cells.”
The microscope-generated video images show protoplasts – cells with their walls removed – of cabbage’s cousin, the flowering plant Arabidopsis, chaotically sprouting filaments of cellulose fibers that gradually self-assemble into a complex network on the outer cell surface.
“I was very surprised by the emergence of ordered structures out of the chaotic dance of molecules when I first saw these video images,” said Lee, who also is a faculty member at the Institute for Quantitative Biomedicine. “I thought plant cellulose would be made in a lot more of an organized fashion, as depicted in classical biology textbooks.”
Cellulose is the most abundant biopolymer – large molecules naturally produced by living organisms – on Earth. A carbohydrate that is the primary structural component of plant cell walls, cellulose is widely used in industry to make a range of products, including paper and clothing. It also is used in filtration, trapping large particles more effectively and enhancing flow, and as a thickening agent in foods such as yogurt and ice cream.
“This discovery opens the door for researchers to begin dissecting the genes that could play various roles for cellulose biosynthesis in the plant,” said Eric Lam, a Distinguished Professor in the Department of Plant Biology in Rutgers School of Environmental and Biological Sciences and an author on the study. “The knowledge gained from these future studies will provide new clues for approaches to design better plants for carbon capture, improve tolerance to all kinds of environmental stresses, from drought to disease, and optimize second-generation cellulosic biofuels production.”
The work is the culmination of a childhood dream for Shishir Chundawat, an associate professor in the Department of Chemical and Biochemical Engineering in the Rutgers School of Engineering and an author on the study.
“I have always been fascinated by plants and how they capture sunlight via leaves into reduced carbon forms like cellulose that form cell walls,” Chundawat said, who plans to explore new ways to produce new, sustainable biofuels and biochemicals from diverse feedstocks like terrestrial plants and marine algae. “I remember back in middle school when I had collected many leaves of different shapes, sizes and colors for a science class report, and being very curious about how plants produce all this myriad complexity and diversity in nature. I was inspired by that experience to delve deeper into the fundamental phenomena of biomass production and its utilization using sustainable engineering to produce valuable bioproducts for societal benefit.”
Scientists from each of the three research teams made unique and critical contributions.
When conventional lab microscopes wouldn’t do, providing at best blurry images of the cell wall-building process, the team turned to an advanced super-resolution and minimally invasive technique called total internal reflection fluorescence microscopy. The approach, which captured images only of the underside surface of cells, was sensitive enough to take videos for 24 hours without bleaching and destroying the cells.
Lee, a biophysicist and an expert on using cutting-edge microscopy techniques to study living systems, developed a custom microscope for the project and oversaw the imaging efforts.
Chundawat led a team that pioneered a technique allowing the scientists to tag the emerging cellulose tendrils with fluorescent protein dye.
Chundawat is a bioengineer and expert on protein engineering and glycosciences, the study of complex carbohydrates such as cellulose. To make the cells fluorescent and detectable by the microscope, he and his team developed a probe derived from an engineered bacterial enzyme that binds specifically to cellulose.
Lam, an expert on plant genetics and biotechnology, and his team found a way to remove the cell wall of individual cells of Arabidopsis to create a “blank slate” for new cell walls to be laid down by protoplast cells.
“This provided little to no background cellulose to confound our visualization and tracking of newly synthesized cellulose under optimized conditions,” Lam said.
Other Rutgers scientists on the study included: Hyun Huh, a postdoctoral scientist with the Institute for Quantitative Biomedicine; Dharanidaran Jayachandran, a doctoral student, and Mohammad Irfan, a postdoctoral scientist in the Department of Chemical and Biochemical Engineering; and Junhong Sun, a lab technician in the Department of Plant Biology.
Animations for young students inspired to learn more about plants are available, however, the Rutgers study shows that the process of cellulose synthesis and cell wall formation is much more complex.
Artistic rendering of cellulose regenerating on a plant protoplast cell surface with zoomed out view. Cellulose is synthesized by plasma membrane-bound enzyme complexes (green) and assembles into a microfibril network (brown), forming the main scaffold for the cell wall.
Credit
Ehsan Faridi/ Inmywork Studio/ Chundawat, Lee and Lam Labs