Wednesday, June 22, 2022

Modern phoenix: The bird brought back from extinction in Japan

Wild tokis have been brought back from local extinction on Japan's Sado island
Wild tokis have been brought back from local extinction on Japan's Sado island.

Every day for the past 14 years, 72-year-old Masaoki Tsuchiya has set out before sunrise to search for a bird rescued from extinction in Japan.

Starting his car under star-dotted skies unpolluted by light, he works alone in the pre-dawn chill, marking sightings or absences in a planner, interrupted only by the crackle of a walkie-talkie.

The bird he is looking for is called "toki" in Japanese, and its presence on his home of Sado island is testament to a remarkable conservation program.

In just under two decades, Japan's population of wild toki has gone from zero to nearly 500, all on Sado, where the bird's delicate pink plumage and distinctive curved beak now draw tourists.

It's a rare conservation success story when one in eight  globally are threatened with extinction, and involved international diplomacy and an agricultural revolution on a  off Japan's west coast.

A cautionary tale

Tsuchiya, stocky and spry with an impish grin, doesn't eat breakfast until he has made all his stops, and after years of practice he can spot chicks hidden in nests through the monocular attached to his rolled-down car window.

He points to virtually imperceptible marks on a road or a wall that help him remember where to park and start surveying.

Conservation timeline of the Japanese crested ibis
Timeline showing how efforts to save the Japanese crested ibis has unfolded.

"The number I see at this spot depends on the season," he explains.

Some days dozens of the  appear in one area, something unimaginable in 2003, when a toki called Kin or "gold" died in a cage on Sado at the record-breaking age of 36.

Her death meant not a single wild-born toki was left in Japan, despite the bird being so synonymous with the country that it is also known as the Japanese crested ibis.

"I knew the day was coming. She was very old and frail," Tsuchiya said. "But it was still a real pity."

Efforts to get Kin to mate with Sado's last wild-born male toki Midori—meaning "green"—had long since failed, and she lived out her last years as a curiosity and a cautionary environmental tale.

Her death made national headlines and appeared to mark the end of a long and seemingly futile battle to protect the toki in Japan, where its feathers even inspire the word for peach pink: "toki-iro".

But now so many roam the skies and rice paddies of Sado that local officials have gone from discouraging eager birdwatchers to training guides to help visitors spot the local icon, and the government is even studying reintroducing the bird elsewhere.

Also known as the Asian crested ibis, Japan's last toki died in 2003
Also known as the Asian crested ibis, Japan's last toki died in 2003.

Wiped out

Wild toki once lived across Japan, as well as in Russia, Taiwan and South Korea.

They were considered a pest that damaged rice plants, but during Japan's Edo era, from 1603 to 1867, hunting restrictions meant only high-ranking officials could actively pursue birds like toki.

That changed in the Meiji era and as guns became more available. Toki meat was believed to have health benefits, and its feathers were favored for everything from dusters to decorative flourishes on hats.

"Over just 40 years, the toki basically disappeared," said Tsuchiya on an observation deck where visitors now try to spot the bird.

By the early 1930s, only a few dozen toki remained in Japan, mostly on Sado and the nearby Noto peninsula, and the species won protected status.

A fresh threat then emerged during Japan's post-war drive for growth: rising use of chemical fertilizers and pesticides.

A small population of toki were found in China and a successful breeding programme allowed the birds to be reintroduced to Sado
A small population of toki were found in China and a successful breeding programme allowed the birds to be reintroduced to Sado.

Toki feed primarily in rice paddies that mimic marshy wetland habitats and they are undiscriminating diners, eating everything from insects to small crabs and frogs.

The chemicals affected the birds and their food, and by 1981 just five wild toki remained in Japan, all on Sado, where officials took them into protective captivity.

But by bizarre coincidence, the same year a population of seven wild toki was discovered in a remote area of China's Shaanxi province, reviving hopes for the bird's survival.

Sado's captive birds failed to mate, but China's program had more success, and when then-Chinese president Jiang Zemin made a historic first state visit in 1998 he offered Japan the gift of a pair of toki.

You You and Yang Yang arrived the following year on first-class seats, producing their first chick months later in an event that led national television broadcasts.

Other birds arrived from China, and with time Sado had a large enough population to consider reintroducing the toki to the wild.

But first they had to tackle the use of chemical fertilizers and pesticides on Sado.

Officials initially struggled to persuade Sado farmers to switch to environmentally friendly fertilisers
Officials initially struggled to persuade Sado farmers to switch to environmentally friendly fertilisers.

"Back then people didn't think about the environment when farming. Their priorities were selling products at a high price and harvesting as much as possible," said Shinichiro Saito, a 60-year-old rice farmer.

Farmers were asked to cut chemical fertilizers and pesticides by half from the level allowed by local rules, but there was pushback.

Fewer chemicals meant smaller harvests, lost income, and more weeding.

And some farmers couldn't see the point of other proposals like underground channels connecting rice fields to rivers to increase the flow of aquatic life.

'Toki-friendly'

Local officials used a carrot-and-stick approach, refusing to buy rice from farmers who rejected the new chemical limits and creating a new premium brand of "toki-friendly" rice for those who did.

But Saito, who was an early adopter, said the real difference came when the first birds were released in 2008.

The creation of a premium "toki-friendly" rice brand encouraged farmers to back conservation efforts
The creation of a premium "toki-friendly" rice brand encouraged farmers to back conservation efforts.

"It was the toki that changed their minds," he said, with a lop-sided grin.

Even farmers reluctant to adapt were "delighted" to see a bird with almost mythical status on Sado wandering through their fields.

"This is a true story. The toki was almost like an environmental ambassador, it helped create a good environment for itself."

Tsuchiya's daily rounds began with the 2008 release.

He has since witnessed triumphs including the first wild-born chick, and the first chick born to wild-born birds—moments he describes with the proud anxiety of a parent sending a child off to school for the first time.

He still runs his own business, though the toki feather tucked into his car's folding mirror makes clear where his heart lies.

And the breeding program has continued, supplemented by birds from China that help broaden the gene pool.

Sado local Masaoki Tsuchiya documents toki nests each morning
Sado local Masaoki Tsuchiya documents toki nests each morning.

Around 20 birds are released twice a year after graduating from a three-month training program that prepares them for life outside a cage.

"They learn how to fly, how to find food and to get used to being around humans," explained Tomoki Tsuchiya, who works with Sado's local government to make the island toki-friendly.

City officials even farm around the birds to acquaint them with the sound.

'Like family'

When the first toki were released on Sado, there were so many gaps in knowledge about the species that volunteers analyzed their droppings to find out what the birds were eating.

There were missteps: officials prepared a remote mountain location for the release, believing the birds would prefer seclusion, but the toki instead flew down to fields that were frequented by farmers.

Tomoki Tsuchiya's interest in toki was fostered by his father, Masaoki.

Japanese crested ibis
Factfile on the Japanese crested ibis that went effectively extinct in the wild in Japan, but has been reintroduced over the course of two decades.

But it is a fascination shared by many on Sado, where the bird is rendered in cute mascot form on everything from T-shirts to milk cartons.

"How can I express it? The toki is so important for people on Sado," the 42-year-old said.

"It's like family."

Even after training, a toki's future is precarious: only about half survive predators like snakes and weasels, and the survival rate for newborn chicks is similar.

But enough have thrived that Japan may expand the Sado program, and there have been successes elsewhere.

In just under two decades, Sado's population of wild toki has gone from zero to nearly 500
In just under two decades, Sado's population of wild toki has gone from zero to nearly 500.

China's wild population now numbers over 4,450, and a South Korean project released 40 toki for the first time in 2019.

For Saito, who speaks as toki squawk nearby, the bird's resurrection is part of a bigger achievement on Sado—a new approach to farming and the environment.

"When this project started, what I dreamed of the most was seeing toki flying overhead while I farmed," he said.

"An environment that is good for toki is an environment that is also safe for humans, and that's something people on Sado can be proud of."

An easy relationship between a beetle and its yeast symbiont

© 2022 AFP

Spider silk properties analyzed for use as bio-based fibers in the medical field

Spider silk properties analyzed for use as bio-based fibers in the medical field
Appearance of the native spider silk samples on stainless steel plate: (a) reeled fibers, (b)
 reeled fibers after removal of lipid layers, (c) films, and (d) non-woven fabrics. 
Credit: Langmuir

Silk has been cultivated for centuries by domesticated silkworms, but it has been difficult to commercially produce spider silk in bulk due to their cannibalistic tendencies. However, spider silk fibers are attracting attention for their fineness, mechanical properties, and lustrous appearance. Spider silk produced through recombinant protein expression systems and chemical synthesis has been shown to have superior properties for medical use to prevent the formation of blood clots and have excellent knot strength to endure repetitive loading and unloading. In this study, published in Langmuir, the cell adhesion behavior of native spider silk was investigated.

The development of cell culture substrates is indispensable for the progress of regenerative medicine. In conventional research, many cell culture substrates made of petroleum-derived polymers have been developed, but the development of protein-derived cell culture substrates has not made much progress. Among the protein-based materials, silkworm  has been used since . In recent years, attention has been focused on spider-derived silk, which has better  than silkworm silk. However, little is known about the cell behavior on spider silk. Therefore, for this study, researchers lead by Dr. Kenjiro Yazawa of Shinshu University aimed to investigate the cell adhesion behavior on spider silk.

In previous studies, experiments were conducted with recombinant spider silk-like proteins instead of natural spider silk. Therefore, the size of the protein was about 1/10 of that of natural spider silk. The research group that includes Dr. Jun Negishi, an expert in biomaterials believed that it is important to collect spider silk directly from live spiders and observe cell adhesion of natural spider silk.

Spider silk properties analyzed for use as bio-based fibers in the medical field
TOC graphic. Credit: Langmuir

The researchers prepared three types of spider silk; reeled fibers, film, and nanofiber (non-woven fabric). It was challenging to wind live spider thread so that it would be oriented in the same direction. However, they were able to achieve this and found that there was a difference in the shape of cell adhesion among the three shapes of spider silk.

This study clarified the adhesion behavior of fibroblasts on spider silk, but it is still necessary to investigate whether there is a difference in cell activity depending on the surface topography. For example, if you know that the cell activity is high on a thread or non-woven fabric or that it is low on film, it will be a new finding. This aspect of native  is currently under investigation.

Regenerative medicine: Spider silk Janus fibers could attract nerve cells and stimulate their growth
More information: Kenjiro Yazawa et al, Cell Adhesion Behaviors on Spider Silk Fibers, Films, and Nanofibers, Langmuir (2022). DOI: 10.1021/acs.langmuir.2c00818
Journal information: Langmuir 
Provided by Shinshu University

Almost 200 unique butterflies live only in Colombia and could be at risk of being lost forever

Scientists reveal almost 200 unique butterflies that live only in Colombia and could be at risk of being lost forever
Mesosemia cordillerensis. Credit: Juan Guillermo Jaramillo

Almost 200 unique species of butterflies live only in Colombia, accounting for 20% of all butterfly species, and they might be at risk. This means that one in five of the world's known butterfly species could be protected in Colombia's territory. The first ever list and identification guide for the endemic species has been just published after almost two centuries of butterfly studies in the country. The bilingual book (English and Spanish) can be downloaded for free from the Natural History Museum website.

The women-led team of authors comprises Dr. Blanca Huertas, a scientist at the Natural History Museum, Yenny Correa Carmona biologist from Universidad de Antioquia in Colombia and Rutherford grant recipient and Jean Francois Le Crom, butterfly expert. The project follows an  between the Colombian Government's board of Tourism, ProColombia, and the Natural History Museum in London, UK.

Many species will be seen for the first time in the book with 500 full color pictures and facts about some of the rarest, precious, and most threatened butterflies in the country. To name a few, the book features a yellow  that was in solitude for almost one hundred years before its female mate was found, a species that has only been collected once in almost 50 years and even a species named after Satan.

Colombia is one of the most diverse countries in the world and the authors of the book hope to encourage more people to protect Colombia's vast butterfly fauna, including international visitors. With improved security following the country's peace accord and the growth in nature appreciation globally, ecotourism experiences are at the top of many travelers' priority lists. However,  and land conversion are threatening many forests in the mountains of Colombia.

Dr. Blanca Huertas, Senior Curator of Lepidoptera at the Natural History Museum, says: "Now knowing which butterfly species have special and limited habitats in Colombia, we hope that the general public engage with their conservation, that scientists can prioritize further studies and governments can protect them. We are letting the world know about the unique treasures of Colombia."

Jose R. Puyana, ProColombia's regional director for Europe said: "From the home to a fifth of the world's entire butterfly population, ProColombia is delighted to support the important work that scientists are doing to identify and celebrate Colombia's unique butterflies. Through partnering with the Natural History Museum, we continue to showcase our precious wildlife and shine a light on Colombia as perhaps the most biodiverse country in the world."

Key facts:

  • The book reveals photos and unknown facts concerning the almost 200 butterflies that live only in Colombia. If lost, they will be lost forever.
  • A yellow butterfly featured in the book is an icon of the famous Nobel book writer Gabriel Garcia Marquez's One Hundred Years of Solitude book.
  • Colombia has almost as many butterflies as Africa (4,000 species) and almost six times than the entire European continent (500 species).
  • Significant improvements in the security of Colombia have led to a new phenomenon of ecotourism, meaning butterflies have potential for increased protection.
  • The Paramos area of the Colombian mountains is the most threatened area and is a vital habitat to the endemic butterfly .
Colombia has the world's largest variety of butterfly species: study

More information: Endemic Butterflies of Colombia: An identification guide for the country's unique species / Mariposas endémicas de Colombia: guía para la identificación de las especies únicas del país. Natural History Museum London & ProColombia. Editorial Puntoaparte, Bogotá Colombia. www.nhm.ac.uk/content/dam/nhmw … iposas-endemicas.pdf
Provided by Natural History Museum 

Seasonal fog alleviates drought stress of rubber trees in Xishuangbanna

Seasonal Fog Alleviates Drought Stress of Rubber Trees in Xishuangbanna----Chinese Academy of Sciences
Rubber plantation in Xishuangbanna. Credit: XTBG

The importance of fog in forest ecosystems has been recognized and debated for centuries. However, the extent to which the leaves of rubber plants can maintain net CO2 assimilation in the fog season is not known.

In a study published in the Journal of Hydrology, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences analyzed carbon/water flux data during 2014–2016 in a mature rubber plantation in Xishuangbanna.

They compared the net ecosystem CO2 exchange, gross primary production, canopy evapotranspiration, crop water productivity, canopy conductance and transpiration rate under foggy and non-foggy days of cool dry (November-February) and hot dry (March-April) seasons to reveal the impact of fog on these carbon and water processes.

The analysis of three years of continuous observation showed that fog occurred during 42% of the total study period, and the majority occurred during the dry season when the temperature was relatively low. The dense foggy days did not affect gross primary production, but decreased canopy evapotranspiration.

In addition to the , fog events were also associated with low vapor pressure deficit, atmospheric water potential,  and frequent wet-canopy conditions. Statistical analysis demonstrated that physiological parameters were mainly regulated by the concomitant changes of air temperature and vapor pressure deficit during cool dry foggy days.

The study suggests that low fog occurrence would cause greater dry season demand for groundwater in  and decrease ecosystem crop water productivity.

"Our study highlights that during foggy days, the rubber plantation utilizes less water and thus increases the crop water productivity. Therefore, the rubber farmers should implement canopy evapotranspiration -based adaptive irrigation management systems for better yield, particularly during the  of the non-foggy season," said Zhang Yiping of XTBG.

Increases in planting density tend to decrease water use efficiency in rubber trees
More information: Palingamoorthy Gnanamoorthy et al, Seasonal fog enhances crop water productivity in a tropical rubber plantation, Journal of Hydrology (2022). DOI: 10.1016/j.jhydrol.2022.128016

Leaf mold compost shows benefit for tomato plants in degraded urban soils

Leaf mold compost shows benefit for tomato plants in degraded urban soils
The tomato plant on the left was grown in soil that did not have leaf mold compost added. 
The plant on the right is an example of the same tomato variety grown in soil that contained
 leaf mold compost. Comparatively, the plant on the right showed more rigorous growth in result of
 using leaf mold compost. The photo was taken at week nine during the study. Credit: Kyle Richardville

Many urban gardeners know that adding ingredients like compost and mulch to their soil has great benefits. But it can be difficult to know what to add and why. Researchers at Purdue University gathered scientific evidence about one specific soil addition, leaf mold compost, and how it benefits tomato plants.

Degraded soils often found in places like towns and cities can lead to vegetables growing poorly and not producing as much food. In addition, these communities produce many kinds of waste that can be composted. In this study, the researchers used "leaf mold" compost from deciduous tree leaves, a common waste stream found in .

"Leaf mold compost differs from traditional compost in that it is not stirred as much," says Lori Hoagland, a professor of soil  at Purdue University. "This slows down the time it takes to create compost, but is claimed by growers to generate a higher quality, or more 'disease suppressive' compost. In particular, leaf mold compost is expected to promote greater colonization by beneficial fungi, which we evaluated in this trial."

The study was published in Urban Agriculture & Regional Food Systems Journal.

The researchers tested if leaf mold can help  produce more tomatoes. They also evaluated if fungal inoculates, often sold to increase tomato yields, get a boost from leaf mold.

Leaf mold compost shows benefit for tomato plants in degraded urban soils
This mixture is three-year-old leaf mold compost that is about to be applied to the soil. Leaf mold
 compost has been found to generate a higher quality, or more ‘disease suppressive’ compost. 
Credit: Kyle Richardville

Their results showed that the leaf mold compost they applied improved many important soil properties that influence the health and productivity of plants. The plants that received leaf mold compost produced many more tomatoes and had less disease. They also found that the compost increased the survival of the beneficial microbial inoculant that can help plants withstand disease pressure. Although they grew tomatoes in this study, the researchers say they suspect many other crops could benefit from leaf mold compost.

"Our recommendation is that compost generated from urban waste streams can improve urban soils and increase plant productivity," Hoagland says. "However, it is important to remember that while compost improves soil and can provide supplemental nutrients for crops, it should not be substituted as a fertilizer. This is because over-application of compost in addition to fertilizers can lead to problems such as the build-up of too much phosphorus."

Hoagland adds that it is important for gardeners to get their soil tested as well. Most standard tests that measure total organic matter and major nutrients like nitrogen and phosphorus are inexpensive, often $10–20 per sample. More detailed tests can be more expensive but also useful. If a gardener is concerned about their soil, they can also get it tested for , such as lead, to know that that their garden soil is safe.

So how can you make and use leaf mold in your own urban garden? According to growers, gardeners can simply pile leaves and stir it occasionally, even once per year. Nature does the rest of the work by slowly decomposing the leaves. In mid-summer, consider putting a tarp over the  pile to build enough heat to kill weed seeds. Avoid putting diseased plant material in the pile. Compost can be used once the leaves have broken down.

Leaf mold compost shows benefit for tomato plants in degraded urban soils
Leaf mold compost was spread across treatment blocks before all the plots were cultivated. All the
 plots, those with and those without compost, were then planted with tomato. A recent study showed
 that the leaf mold compost they applied improved many important soil properties that influence the
 health and productivity of plants. Credit: Lori Hoagland

According to Hoagland, many cities lack urban composting programs so valuable wastes like leaves end up in landfills rather than soil. People can petition their city to start a program or find a way to compost their own. Home gardeners can also  their own leaves, as well as food scraps like coffee grounds to produce valuable  amendments.

"What makes the study unique is that we were using local waste streams within a city to help 'close the loop,'" Hoagland explains. "Using urban waste streams in this way can not only help promote , but will reduce municipal costs and protect the environment by keeping this 'waste' out of landfills."Some smart ways to jumpstart your recycling program


More information: Kyle Richardville et al, Leaf mold compost reduces waste, improves soil and microbial properties, and increases tomato productivity, Urban Agriculture & Regional Food Systems (2022). DOI: 10.1002/uar2.20022]
Provided by American Society of Agronomy 

Light it up: Using firefly genes to understand cannabis biology

Light it up: Using firefly genes to understand cannabis biology
Yi Ma near cannabis plants in the CAHNR Greenhouse. Credit: Jason Sheldon/UConn Photo

Cannabis, a plant gaining ever-increasing attention for its wide-ranging medicinal properties, contains dozens of compounds known as cannabinoids.

One of the best-known cannabinoids is cannabidiolic acid (CBD), which is used to treat pain, inflammation, nausea and more.

Cannabinoids are produced by trichomes, small spikey protrusions on the surface of cannabis flowers. Beyond this fact, scientists know very little about how cannabinoid biosynthesis is controlled.

Yi Ma, research assistant professor, and Gerry Berkowitz, professor in the College of Agriculture, Health and Natural Resources, investigated the underlying molecular mechanisms behind trichrome development and cannabinoid synthesis.

Berkowitz and Ma, along with former graduate students Samuel Haiden and Peter Apicella, discovered transcription factors responsible for trichome initiation and cannabinoid biosynthesis. Transcription factors are molecules that determine if a piece of an organism's DNA will be transcribed into RNA, and thus expressed.

In this case, the transcription factors cause  on the flowers to morph into trichomes. The team's discovery was recently published as a feature article in Plants. Related trichome research was also published in Plant Direct. Due to the gene's potential economic impact, UConn has filed a provisional patent application on the technology.

Building on their results, the researchers will continue to explore how these transcription factors play a role in trichome development during flower maturation.

Berkowitz and Ma will clone the promoters (the part of DNA that transcription factors bind to) of interest. They will then put the promoters into the cells of a model plant along with a copy of the gene that makes fireflies light up, known as firefly luciferase; the luciferase is fused to the cannabis promoter so if the promoter is activated by a signal, the luciferase reporter will generate light. "It's a nifty way to evaluate signals that orchestrate cannabinoid synthesis and trichome development," says Berkowitz.

The researchers will load the cloned promoters and luciferase into a plasmid. Plasmids are circular DNA molecules that can replicate independently of the chromosomes. This allows the scientists to express the genes of interest even though they aren't part of the plant's genomic DNA. They will deliver these plasmids into the plant leaves or protoplasts, plant cells without the cell wall.

When the promoter controlling luciferase expression comes into contact with the transcription factors responsible for trichome development (or triggered by other signals such as plant hormones), the luciferase "reporter" will produce light. Ma and Berkowitz will use an instrument called a luminometer, which measures how much light comes from the sample. This will tell the researchers if the promoter regions they are looking at are controlled by  responsible for increasing trichome development or modulating genes that code for cannabinoid biosynthetic enzymes. They can also learn if the promoters respond to hormonal signals.

In prior work underlying the rationale for this experimental approach, Ma and Berkowitz along with graduate student Peter Apicella found that the enzyme that makes THC in cannabis trichomes may not be the critical limiting step regulating THC production, but rather the generation of the precursor for THC (and CBD) production and the transporter-facilitated shuttling of the precursor to the extracellular bulb might be key determinants in developing cannabis strains with high THC or CBD.

Most cannabis farmers grow hemp, a variety of cannabis with naturally lower THC levels than marijuana. Currently, most hemp varieties that have high CBD levels also contain unacceptably high levels of THC. This is likely because the hemp plants still make the enzyme that produces THC. If the plant contains over 0.3% THC, it is considered federally illegal and, in many cases, must be destroyed. A better understanding of how the plant produces THC means scientists could selectively knock out the enzyme that synthesizes THC using genome editing techniques such as CRISPR. This would produce plants with lower levels of or no THC.

"We envision that the fundamental knowledge obtained can be translated into novel genetic tools and strategies to improve the cannabinoid profile, aid hemp farmers with the common problem of overproducing THC, and benefit ," the researchers say.

On the other hand, this knowledge could lead to the production of cannabis plants that produce more of a desired , making it more valuable and profitable.The frostier the flower, the more potent the cannabis

More information: Samuel R. Haiden et al, Overexpression of CsMIXTA, a Transcription Factor from Cannabis sativa, Increases Glandular Trichome Density in Tobacco Leaves, Plants (2022). DOI: 10.3390/plants11111519

Peter V. Apicella et al, Delineating genetic regulation of cannabinoid biosynthesis during female flower development in Cannabis sativa, Plant Direct (2022). DOI: 10.1002/pld3.412

Inexpensive method detects synthetic cannabinoids, banned pesticides

Inexpensive method detects synthetic cannabinoids, banned pesticides
Protein structure-guided design of high-affinity PYR1-based cannabinoid sensors. a, The 
19 side chains of residues in PYR1’s binding pocket targeted for double-site mutagenesis
 (DSM) are shown along with ABA (yellow) and HAB1’s W385 ‘lock’ residue and water 
network (3QN1). b, Sensor evolution pipeline. The PYR1 library was constructed by NM in
 two subpools, one using single-mutant oligos and another using double-mutant oligo 
pools. The combined pools were screened for sensors using Y2H growth selections in the 
presence of a ligand of interest. c, Representative screen results. The DSM library was
 screened for mutants that respond to the synthetic cannabinoid JWH-015 yielding five hits
 that were subsequently optimized by two rounds of DNA shuffling to yield PYR1JWH-015
which harbors four mutations. The yeast two-hybrid (Y2H) staining data show different
 receptor responses to JWH-015 by β-galactosidase activity. Credit: Nature Biotechnology
 (2022). DOI: 10.1038/s41587-022-01364-5

Scientists have modified proteins involved in plants' natural response to stress, making them the basis of innovative tests for multiple chemicals, including banned pesticides and deadly, synthetic cannabinoids.

During drought, plants produce ABA, a hormone that helps them hold on to water. Additional proteins, called receptors, help the plant recognize and respond to ABA. UC Riverside researchers helped demonstrate that these ABA receptors can be easily modified to quickly signal the presence of nearly 20 different chemicals.

The research team's work in transforming these plant-based molecules is described in a new Nature Biotechnology journal article.

Researchers frequently need to detect all kinds of molecules, including those that harm people or the environment. Though methods to do that exist, they are often costly and require complicated equipment.

"It would be transformative if we could develop rapid dipstick tests to know if a dangerous chemical, like a synthetic cannabinoid, is present. This new paper gives others a roadmap to doing that," said Sean Cutler, a UCR plant cell biology professor and paper co-author.

The problem with  is something Cutler calls, "regulatory whack-a-mole." Because they send people to the hospital, authorities have attempted to outlaw them in this country. However, dozens of new versions emerge every year before they can be controlled.

"Our system could be configured to detect lab-made cannabinoid variations as quickly as they appear on the market," Cutler said.

The research team also demonstrated their  can signal the presence of organophosphates, which includes many banned pesticides that are toxic and potentially lethal to humans. Not all organophosphate pesticides are banned but being able to quickly detect the ones that are could help officials monitor  without more expensive testing at laboratories.

For this project, the researchers demonstrated the system in laboratory-grown yeast cells. In the future, the team would like to put the modified molecules back into plants that could serve as biological sensors. In that case, a chemical in the environment could cause leaves to turn specific colors or change temperatures.

Although the work focuses on cannabinoids and pesticides, the key breakthrough here is the ability to rapidly develop diagnostics for chemicals using a simple and inexpensive system. "If we can expand this to lots of other chemical classes, this is a big step forward because developing new tests can be a slow process," said Ian Wheeldon, study co-author and UCR .

This research was developed through a contract with the Donald Danforth Plant Science Center to support the Defense Advanced Research Projects Agency (DARPA) Advanced Plant Technologies (APT) program. The team included scientists from the Medical College of Wisconsin, Michigan State University, and the Donald Danforth Plant Science Center in St. Louis. This work was facilitated by chemical and biological engineer Timothy Whitehead at the University of Colorado, Boulder.

To create this system, researchers took advantage of the ABA plant stress hormone's ability to switch receptor molecules on and off. In the "on" position, the receptors bind to another protein, forming a tight complex that can trigger visible responses, like glowing. Whitehead, a collaborator on the work, used state-of-the-art computational tools to help redesign the receptors, which was critical to the success of the group's work.

"We take an enzyme that can glow in the right context and split it into two pieces. One piece on the switch, and the other on the protein it binds to," Cutler said. "This trick of bringing two things together in the presence of a third chemical isn't new. Our advance is showing we can reprogram the process to work with lots of different third chemicals."

Game changer: New chemical keeps plants plump
More information: Jesús Beltrán et al, Rapid biosensor development using plant hormone receptors as reprogrammable scaffolds, Nature Biotechnology (2022). DOI: 10.1038/s41587-022-01364-5
Journal information: Nature Biotechnology 
Provided by University of California - Riverside