Category Archives: agriculture

Alan Copperman and Amanda Marcotte have a very US-centric discussion about CRISPR and germline editing (designer babies?)

For anyone who needs more information, I ran a three part series on CRISPR germline editing on August 15, 2017:

Part 1 opens the series with a basic description of CRISPR and the germline research that occasioned the series along with some of the ethical issues and patent disputes that are arising from this new technology. CRISPR and editing the germline in the US (part 1 of 3): In the beginning

Part 2 covers three critical responses to the reporting and between them describe the technology in more detail and the possibility of ‘designer babies’.  CRISPR and editing the germline in the US (part 2 of 3): ‘designer babies’?

Part 3 is all about public discussion or, rather, the lack of and need for according to a couple of social scientists. Informally, there is some discussion via pop culture and Joelle Renstrom notes although she is focused on the larger issues touched on by the television series, Orphan Black and as I touch on in my final comments. CRISPR and editing the germline in the US (part 3 of 3): public discussions and pop culture

The news about CRISPR and germline editing by a US team made a bit of a splash even being mentioned on Salon.com, which hardly ever covers any science news (except for some occasional climate change pieces). In a Sept. 4, 2017 salon.com item (an excerpt from the full interview) Amanda Marcotte talks with Dr. Alan Copperman director of the division of reproductive endocrinology and infertility at Mount Sinai Medical Center about the technology and its implications.  As noted in the headline, it’s a US-centric discussion where assumptions are made about who will be leading discussions about the future of the technology.

It’s been a while since I’ve watched it but I believe they do mention in passing that Chinese scientists published two studies about using CRISPR to edit the germline (i think there’s a third Chinese paper in the pipeline) before the American team announced its accomplishment in August 2017. By the way, the first paper by the Chinese caused quite the quandary in April 2015. (My May 14, 2015 posting covers some of the ethical issues; scroll down about 50% of the way for more about the impact of the published Chinese research.)

Also, you might want notice just how smooth Copperman’s responses are almost always emphasizing the benefits of the technology before usually answering the question. He’s had media training and he’s good at this.

They also talk about corn and CRISPR just about the time that agricultural research was announced. Interesting timing, non? (See my Oct. 11, 2017 posting about CRISPR edited corn coming to market in 2020.)

For anyone who wants to skip to the full Marcotte/Cooperman interview, go here on Facebook.

CRISPR corn to come to market in 2020

It seems most of the recent excitement around CRISPR/CAS9 (clustered regularly interspaced short palindromic repeats) has focused on germline editing, specifically human embryos. Most people don’t realize that the first ‘CRISPR’ product is slated to enter the US market in 2020. A June 14, 2017 American Chemical Society news release (also on EurekAlert) provides a preview,

The gene-editing technique known as CRISPR/Cas9 made a huge splash in the news when it was initially announced. But the first commercial product, expected around 2020, could make it to the market without much fanfare: It’s a waxy corn destined to contribute to paper glue and food thickeners. The cover story of Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, explores what else is in the works.

Melody M. Bomgardner, a senior editor at C&EN [Chemical & Engineering News], notes that compared to traditional biotechnology, CRISPR allows scientists to add and remove specific genes from organisms with greater speed, precision and oftentimes, at a lower cost. Among other things, it could potentially lead to higher quality cotton, non-browning mushrooms, drought-resistant corn and — finally — tasty, grocery store tomatoes.

Some hurdles remain, however, before more CRISPR products become available. Regulators are assessing how they should approach crops modified with the technique, which often (though not always) splices genes into a plant from within the species rather than introducing a foreign gene. And scientists still don’t understand all the genes in any given crop, much less know which ones might be good candidates for editing. Luckily, researchers can use CRISPR to find out.

Melody M. Bomgardner’s June 12, 2017 article for C&EN describes in detail how CRISPR could significantly change agriculture (Note: Links have been removed),

When the seed firm DuPont Pioneer first announced the new corn in early 2016, few people paid attention. Pharmaceutical companies using CRISPR for new drugs got the headlines instead.

But people should notice DuPont’s waxy corn because using CRISPR—an acronym for clustered regularly interspaced short palindromic repeats—to delete or alter traits in plants is changing the world of plant breeding, scientists say. Moreover, the technique’s application in agriculture is likely to reach the public years before CRISPR-aided drugs hit the market.

Until CRISPR tools were developed, the process of finding useful traits and getting them into reliable, productive plants took many years. It involved a lot of steps and was plagued by randomness.

“Now, because of basic research in the lab and in the field, we can go straight after the traits we want,” says Zachary Lippman, professor of biological sciences at Cold Spring Harbor Laboratory. CRISPR has been transformative, Lippman says. “It’s basically a freight train that’s not going to stop.”

Proponents hope consumers will embrace gene-edited crops in a way that they did not accept genetically engineered ones, especially because they needn’t involve the introduction of genes from other species—a process that gave rise to the specter of Frankenfood.

But it’s not clear how consumers will react or if gene editing will result in traits that consumers value. And the potential commercial uses of CRISPR may narrow if agriculture agencies in the U.S. and Europe decide to regulate gene-edited crops in the same way they do genetically engineered crops.

DuPont Pioneer expects the U.S. to treat its gene-edited waxy corn like a conventional crop because it does not contain any foreign genes, according to Neal Gutterson, the company’s vice president of R&D. In fact, the waxy trait already exists in some corn varieties. It gives the kernels a starch content of more than 97% amylopectin, compared with 75% amylopectin in regular feed corn. The rest of the kernel is amylose. Amylopectin is more soluble than amylose, making starch from waxy corn a better choice for paper adhesives and food thickeners.

Like most of today’s crops, DuPont’s current waxy corn varieties are the result of decades of effort by plant breeders using conventional breeding techniques.

Breeders identify new traits by examining unusual, or mutant, plants. Over many generations of breeding, they work to get a desired trait into high-performing (elite) varieties that lack the trait. They begin with a first-generation cross, or hybrid, of a mutant and an elite plant and then breed several generations of hybrids with the elite parent in a process called backcrossing. They aim to achieve a plant that best approximates the elite version with the new trait.

But it’s tough to grab only the desired trait from a mutant and make a clean getaway. DuPont’s plant scientists found that the waxy trait came with some genetic baggage; even after backcrossing, the waxy corn plant did not offer the same yield as elite versions without the trait. The disappointing outcome is common enough that it has its own term: yield drag.

Because the waxy trait is native to certain corn plants, DuPont did not have to rely on the genetic engineering techniques that breeders have used to make herbicide-tolerant and insect-resistant corn plants. Those commonly planted crops contain DNA from other species.

In addition to giving some consumers pause, that process does not precisely place the DNA into the host plant. So researchers must raise hundreds or thousands of modified plants to find the best ones with the desired trait and work to get that trait into each elite variety. Finally, plants modified with traditional genetic engineering need regulatory approval in the U.S. and other countries before they can be marketed.

Instead, DuPont plant scientists used CRISPR to zero in on, and partially knock out, a gene for an enzyme that produces amylose. By editing the gene directly, they created a waxy version of the elite corn without yield drag or foreign DNA.

Plant scientists who adopt gene editing may still need to breed, measure, and observe because traits might not work well together or bring a meaningful benefit. “It’s not a panacea,” Lippman says, “but it is one of the most powerful tools to come around, ever.”

It’s an interesting piece which answers the question of why tomatoes from the grocery store don’t taste good.

Korean researchers extend food shelf *life* with nanomicrobial coating

These Korean scientists have applied their new coating to food and to shoe insoles as they test various uses for their technology. From an Aug. 11, 2017 news item on Nanowerk,

The edible coating on produce has drawn a great deal of attention in the food and agricultural industry. It could not only prolong postharvest shelf life of produce against external changes in the environment but also provide additional nutrients to be useful for human health. However, most versions of the coating have had intrinsic limitations in their practical application.

First, highly specific interactions between coating materials and target surfaces are required for a stable and durable coating. Even further, the coating of bulk substrates, such as fruits, is time consuming or is not achievable in the conventional solution-based coating. In this respect, material-independent and rapid coating strategies are highly demanded.

The research team led by Professor Insung Choi of the Department of Chemistry developed a sprayable nanocoating technique using plant-derived polyphenol that can be applied to any surface.

An Aug. 10, 2017 KAIST (Korea Advanced Institute of Science and Technology) press release, which originated the news item, expands on the theme,

Polyphenols, a metabolite of photosynthesis, possess several hydroxyl groups and are found in a large number of plants showing excellent antioxidant properties. They have been widely used as a nontoxic food additive and are known to exhibit antibacterial, as well as potential anti-carcinogenic capabilities. Polyphenols can also be used with iron ions, which are naturally found in the body, to form an adhesive complex, which has been used in leather tanning, ink, etc.

The research team combined these chemical properties of polyphenol-iron complexes with spray techniques to develop their nanocoating technology. Compared to conventional immersion coating methods, which dip substrates in specialized coating solutions, this spray technique can coat the select areas more quickly. The spray also prevents cross contamination, which is a big concern for immersion methods. The research team has showcased the spray’s ability to coat a variety of different materials, including metals, plastics, glass, as well as textile fabrics. The polyphenol complex has been used to form antifogging films on corrective lenses, as well as antifungal treatments for shoe soles, demonstrating the versatility of their technique.

Furthermore, the spray has been used to coat produce with a naturally antibacterial, edible film. The coatings significantly improved the shelf life of tangerines and strawberries, preserving freshness beyond 28 days and 58 hours, respectively. (Uncoated fruit decomposed and became moldy under the same conditions). See the image below.

 

a –I, II: Uncoated and coated tangerines incubated for 14 and 28 days in daily-life settings

b –I: Uncoated and coated strawberries incubated for 58 hours in daily-life settings

b –II: Statistical investigation of the resulting edibility.

Professor Choi said, “Nanocoating technologies are still in their infancy, but they have untapped potential for exciting applications. As we have shown, nanocoatings can be easily adapted for several different uses, and the creative combination of existing nanomaterials and coating methods can synergize to unlock this potential.”

Here’s a link to and a citation for the paper,

Antimicrobial spray nanocoating of supramolecular Fe(III)-tannic acid metal-organic coordination complex: applications to shoe insoles and fruits by Ji Park, Sohee Choi, Hee Moon, Hyelin Seo, Ji Kim, Seok-Pyo Hong, Bong Lee, Eunhye Kang, Jinho Lee, Dong Ryu, & Insung S. Choi. Scientific Reports 7, Article number: 6980 (2017) doi:10.1038/s41598-017-07257-x Published online: 01 August 2017

This paper is open access.

*’life’ added to correct headline on Sept. 4, 2017.

US Dept. of Agriculture announces its nanotechnology research grants

I don’t always stumble across the US Department of Agriculture’s nanotechnology research grant announcements but I’m always grateful when I do as it’s good to find out about  nanotechnology research taking place in the agricultural sector. From a July 21, 2017 news item on Nanowerk,,

The U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) today announced 13 grants totaling $4.6 million for research on the next generation of agricultural technologies and systems to meet the growing demand for food, fuel, and fiber. The grants are funded through NIFA’s Agriculture and Food Research Initiative (AFRI), authorized by the 2014 Farm Bill.

“Nanotechnology is being rapidly implemented in medicine, electronics, energy, and biotechnology, and it has huge potential to enhance the agricultural sector,” said NIFA Director Sonny Ramaswamy. “NIFA research investments can help spur nanotechnology-based improvements to ensure global nutritional security and prosperity in rural communities.”

A July 20, 2017 USDA news release, which originated the news item, lists this year’s grants and provides a brief description of a few of the newly and previously funded projects,

Fiscal year 2016 grants being announced include:

Nanotechnology for Agricultural and Food Systems

  • Kansas State University, Manhattan, Kansas, $450,200
  • Wichita State University, Wichita, Kansas, $340,000
  • University of Massachusetts, Amherst, Massachusetts, $444,550
  • University of Nevada, Las Vegas, Nevada,$150,000
  • North Dakota State University, Fargo, North Dakota, $149,000
  • Cornell University, Ithaca, New York, $455,000
  • Cornell University, Ithaca, New York, $450,200
  • Oregon State University, Corvallis, Oregon, $402,550
  • University of Pennsylvania, Philadelphia, Pennsylvania, $405,055
  • Gordon Research Conferences, West Kingston, Rhode Island, $45,000
  • The University of Tennessee,  Knoxville, Tennessee, $450,200
  • Utah State University, Logan, Utah, $450,200
  • The George Washington University, Washington, D.C., $450,200

Project details can be found at the NIFA website (link is external).

Among the grants, a University of Pennsylvania project will engineer cellulose nanomaterials [emphasis mine] with high toughness for potential use in building materials, automotive components, and consumer products. A University of Nevada-Las Vegas project will develop a rapid, sensitive test to detect Salmonella typhimurium to enhance food supply safety.

Previously funded grants include an Iowa State University project in which a low-cost and disposable biosensor made out of nanoparticle graphene that can detect pesticides in soil was developed. The biosensor also has the potential for use in the biomedical, environmental, and food safety fields. University of Minnesota (link is external) researchers created a sponge that uses nanotechnology to quickly absorb mercury, as well as bacterial and fungal microbes from polluted water. The sponge can be used on tap water, industrial wastewater, and in lakes. It converts contaminants into nontoxic waste that can be disposed in a landfill.

NIFA invests in and advances agricultural research, education, and extension and promotes transformative discoveries that solve societal challenges. NIFA support for the best and brightest scientists and extension personnel has resulted in user-inspired, groundbreaking discoveries that combat childhood obesity, improve and sustain rural economic growth, address water availability issues, increase food production, find new sources of energy, mitigate climate variability and ensure food safety. To learn more about NIFA’s impact on agricultural science, visit www.nifa.usda.gov/impacts, sign up for email updates (link is external) or follow us on Twitter @USDA_NIFA (link is external), #NIFAImpacts (link is external).

Given my interest in nanocellulose materials (Canada was/is a leader in the production of cellulose nanocrystals [CNC] but there has been little news about Canadian research into CNC applications), I used the NIFA link to access the table listing the grants and clicked on ‘brief’ in the View column in the University of Pennsylania row to find this description of the project,

ENGINEERING CELLULOSE NANOMATERIALS WITH HIGH TOUGHNESS

NON-TECHNICAL SUMMARY: Cellulose nanofibrils (CNFs) are natural materials with exceptional mechanical properties that can be obtained from renewable plant-based resources. CNFs are stiff, strong, and lightweight, thus they are ideal for use in structural materials. In particular, there is a significant opportunity to use CNFs to realize polymer composites with improved toughness and resistance to fracture. The overall goal of this project is to establish an understanding of fracture toughness enhancement in polymer composites reinforced with CNFs. A key outcome of this work will be process – structure – fracture property relationships for CNF-reinforced composites. The knowledge developed in this project will enable a new class of tough CNF-reinforced composite materials with applications in areas such as building materials, automotive components, and consumer products.The composite materials that will be investigated are at the convergence of nanotechnology and bio-sourced material trends. Emerging nanocellulose technologies have the potential to move biomass materials into high value-added applications and entirely new markets.

It’s not the only nanocellulose material project being funded in this round, there’s this at North Dakota State University, from the NIFA ‘brief’ project description page,

NOVEL NANOCELLULOSE BASED FIRE RETARDANT FOR POLYMER COMPOSITES

NON-TECHNICAL SUMMARY: Synthetic polymers are quite vulnerable to fire.There are 2.4 million reported fires, resulting in 7.8 billion dollars of direct property loss, an estimated 30 billion dollars of indirect loss, 29,000 civilian injuries, 101,000 firefighter injuries and 6000 civilian fatalities annually in the U.S. There is an urgent need for a safe, potent, and reliable fire retardant (FR) system that can be used in commodity polymers to reduce their flammability and protect lives and properties. The goal of this project is to develop a novel, safe and biobased FR system using agricultural and woody biomass. The project is divided into three major tasks. The first is to manufacture zinc oxide (ZnO) coated cellulose nanoparticles and evaluate their morphological, chemical, structural and thermal characteristics. The second task will be to design and manufacture polymer composites containing nano sized zinc oxide and cellulose crystals. Finally the third task will be to test the fire retardancy and mechanical properties of the composites. Wbelieve that presence of zinc oxide and cellulose nanocrystals in polymers will limit the oxygen supply by charring, shielding the surface and cellulose nanocrystals will make composites strong. The outcome of this project will help in developing a safe, reliable and biobased fire retardant for consumer goods, automotive, building products and will help in saving human lives and property damage due to fire.

One day, I hope to hear about Canadian research into applications for nanocellulose materials. (fingers crossed for good luck)

Are plants and brains alike?

The answer to the question about whether brains and plants are alike is the standard ‘yes and no’. That said, there are some startling similarities from a statistical perspective (from a July 6, 2017 Salk Institute news release (also received via email; Note: Links have been removed),

Plants and brains are more alike than you might think: Salk scientists discovered that the mathematical rules governing how plants grow are similar to how brain cells sprout connections. The new work, published in Current Biology on July 6, 2017, and based on data from 3D laser scanning of plants, suggests there may be universal rules of logic governing branching growth across many biological systems.

“Our project was motivated by the question of whether, despite all the diversity we see in plant forms, there is some form or structure they all share,” says Saket Navlakha, assistant professor in Salk’s Center for Integrative Biology and senior author of the paper. “We discovered that there is—and, surprisingly, the variation in how branches are distributed in space can be described mathematically by something called a Gaussian function, which is also known as a bell curve.”

Being immobile, plants have to find creative strategies for adjusting their architecture to address environmental challenges, like being shaded by a neighbor. The diversity in plant forms, from towering redwoods to creeping thyme, is a visible sign of these strategies, but Navlakha wondered if there was some unseen organizing principle at work. To find out, his team used high-precision 3D scanning technology to measure the architecture of young plants over time and quantify their growth in ways that could be analyzed mathematically.

“This collaboration arose from a conversation that Saket and I had shortly after his arrival at Salk,” says Professor and Director of the Plant Molecular and Cellular Biology Laboratory Joanne Chory, who, along with being the Howard H. and Maryam R. Newman Chair in Plant Biology, is also a Howard Hughes Medical Investigator and one of the paper’s coauthors. “We were able to fund our studies thanks to Salk’s innovation grant program and the Howard Hughes Medical Institute.”

The team began with three agriculturally valuable crops: sorghum, tomato and tobacco. The researchers grew the plants from seeds under conditions the plants might experience naturally (shade, ambient light, high light, high heat and drought). Every few days for a month, first author Adam Conn scanned each plant to digitally capture its growth. In all, Conn scanned almost 600 plants.

“We basically scanned the plants like you would scan a piece of paper,” says Conn, a Salk research assistant. “But in this case the technology is 3D and allows us to capture a complete form—the full architecture of how the plant grows and distributes branches in space.”

From left: Adam Conn and Saket Navlakha
From left: Adam Conn and Saket Navlakha Credit: Salk Institute

Each plant’s digital representation is called a point cloud, a set of 3D coordinates in space that can be analyzed computationally. With the new data, the team built a statistical description of theoretically possible plant shapes by studying the plant’s branch density function. The branch density function depicts the likelihood of finding a branch at any point in the space surrounding a plant.

This model revealed three properties of growth: separability, self-similarity and a Gaussian branch density function. Separability means that growth in one spatial direction is independent of growth in other directions. According to Navlakha, this property means that growth is very simple and modular, which may let plants be more resilient to changes in their environment. Self-similarity means that all the plants have the same underlying shape, even though some plants may be stretched a little more in one direction, or squeezed in another direction. In other words, plants don’t use different statistical rules to grow in shade than they do to grow in bright light. Lastly, the team found that, regardless of plant species or growth conditions, branch density data followed a Gaussian distribution that is truncated at the boundary of the plant. Basically, this says that branch growth is densest near the plant’s center and gets less dense farther out following a bell curve.

The high level of evolutionary efficiency suggested by these properties is surprising. Even though it would be inefficient for plants to evolve different growth rules for every type of environmental condition, the researchers did not expect to find that plants would be so efficient as to develop only a single functional form. The properties they identified in this work may help researchers evaluate new strategies for genetically engineering crops.

Previous work by one of the paper’s authors, Charles Stevens, a professor in Salk’s Molecular Neurobiology Laboratory, found the same three mathematical properties at work in brain neurons. “The similarity between neuronal arbors and plant shoots is quite striking, and it seems like there must be an underlying reason,” says Stevens. “Probably, they both need to cover a territory as completely as possible but in a very sparse way so they don’t interfere with each other.”

The next challenge for the team is to identify what might be some of the mechanisms at the molecular level driving these changes. Navlakha adds, “We could see whether these principles deviate in other agricultural species and maybe use that knowledge in selecting plants to improve crop yields.”

Should you not be able to access the news release, you can find the information in a July 6, 2017 news item on ScienceDaily.

For the paper, here’s a link and a citation,

A Statistical Description of Plant Shoot Architecture by Adam Conn, Ullas V. Pedmale4, Joanne Chory, Charles F. Stevens, Saket Navlakha. Current Biology DOI: http://dx.doi.org/10.1016/j.cub.2017.06.009 Publication stage: In Press Corrected Proof July 2017

This paper is behind a paywall.

Here’s an image that illustrates the principles the researchers are attempting to establish,

This illustration represents how plants use the same rules to grow under widely different conditions (for example, cloudy versus sunny), and that the density of branches in space follows a Gaussian (“bell curve”) distribution, which is also true of neuronal branches in the brain. Credit: Salk Institute

Nanoparticle fertilizer and dreams of a new ‘Green’ revolution

There were hints even while it was happening that the ‘Green Revolution’ of the 1960s was not all it was touted to be. (For those who haven’t come across the term before, the Green Revolution was a better way to farm, a way that would feed everyone on earth. Or, that was the dream.)

Perhaps this time, they’ll be more successful. From a Jan. 15, 2017 news item on ScienceDaily, which offers a perspective on the ‘Green Revolution’ that differs from mine,

The “Green Revolution” of the ’60s and ’70s has been credited with helping to feed billions around the world, with fertilizers being one of the key drivers spurring the agricultural boom. But in developing countries, the cost of fertilizer remains relatively high and can limit food production. Now researchers report in the journal ACS Nano a simple way to make a benign, more efficient fertilizer that could contribute to a second food revolution.

A Jan. 25, 2017 American Chemical Society news release on EurekAlert, which originated the news item, expands on the theme,

Farmers often use urea, a rich source of nitrogen, as fertilizer. Its flaw, however, is that it breaks down quickly in wet soil and forms ammonia. The ammonia is washed away, creating a major environmental issue as it leads to eutrophication of water ways and ultimately enters the atmosphere as nitrogen dioxide, the main greenhouse gas associated with agriculture. This fast decomposition also limits the amount of nitrogen that can get absorbed by crop roots and requires farmers to apply more fertilizer to boost production. However, in low-income regions where populations continue to grow and the food supply is unstable, the cost of fertilizer can hinder additional applications and cripple crop yields. Nilwala Kottegoda, Veranja Karunaratne, Gehan Amaratunga and colleagues wanted to find a way to slow the breakdown of urea and make one application of fertilizer last longer.

To do this, the researchers developed a simple and scalable method for coating hydroxyapatite (HA) nanoparticles with urea molecules. HA is a mineral found in human and animal tissues and is considered to be environmentally friendly. In water, the hybridization of the HA nanoparticles and urea slowly released nitrogen, 12 times slower than urea by itself. Initial field tests on rice farms showed that the HA-urea nanohybrid lowered the need for fertilizer by one-half. The researchers say their development could help contribute to a new green revolution to help feed the world’s continuously growing population and also improve the environmental sustainability of agriculture.

Here’s a link to and a citation for the paper,

Urea-Hydroxyapatite Nanohybrids for Slow Release of Nitrogen by Nilwala Kottegoda, Chanaka Sandaruwan, Gayan Priyadarshana, Asitha Siriwardhana, Upendra A. Rathnayake, Danushka Madushanka Berugoda Arachchige, Asurusinghe R. Kumarasinghe, Damayanthi Dahanayake, Veranja Karunaratne, and Gehan A. J. Amaratunga. ACS Nano, Article ASAP DOI: 10.1021/acsnano.6b07781 Publication Date (Web): January 25, 2017

Copyright © 2017 American Chemical Society

This paper is open access.

Clay nanosheets and world food security

This is some interesting agricultural research from Australia. From a Jan. 11, 2017 news item on phys.org,

A University of Queensland team has made a discovery that could help conquer the greatest threat to global food security – pests and diseases in plants.

Research leader Professor Neena Mitter said BioClay – an environmentally sustainable alternative to chemicals and pesticides – could be a game-changer for crop protection.

“In agriculture, the need for new control agents grows each year, driven by demand for greater production, the effects of climate change, community and regulatory demands, and toxicity and pesticide resistance,” she said.

“Our disruptive research involves a spray of nano-sized degradable clay used to release double-stranded RNA, that protects plants from specific disease-causing pathogens.”

The research, by scientists from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) and UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN) is published in Nature Plants.

A Jan. 11, 2017 University of Queensland press release, which originated the news item, provides a bit more detail,

Professor Mitter said the technology reduced the use of pesticides without altering the genome of the plants.

“Once BioClay is applied, the plant ‘thinks’ it is being attacked by a disease or pest insect and responds by protecting itself from the targeted pest or disease.

“A single spray of BioClay protects the plant and then degrades, reducing the risk to the environment or human health.”

She said BioClay met consumer demands for sustainable crop protection and residue-free produce.

“The cleaner approach will value-add to the food and agri-business industry, contributing to global food security and to a cleaner, greener image of Queensland.”

AIBN’s Professor Zhiping Xu said BioClay combined nanotechnology and biotechnology.

“It will produce huge benefits for agriculture in the next several decades, and the applications will expand into a much wider field of primary agricultural production,” Professor Xu said.

Here’s a link to and a citation for the paper,

Clay nanosheets for topical delivery of RNAi for sustained protection against plant viruses by Neena Mitter, Elizabeth A. Worrall, Karl E. Robinson, Peng Li, Ritesh G. Jain, Christelle Taochy, Stephen J. Fletcher, Bernard J. Carroll, G. Q. (Max) Lu & Zhi Ping Xu. Nature Plants 3, Article number: 16207 (2017) doi:10.1038/nplants.2016.207 Published online: 09 January 2017

This paper is behind a paywall.

I don’t usually do this but here’s the abstract for the paper,

Topical application of pathogen-specific double-stranded RNA (dsRNA) for virus resistance in plants represents an attractive alternative to transgenic RNA interference (RNAi). However, the instability of naked dsRNA sprayed on plants has been a major challenge towards its practical application. We demonstrate that dsRNA can be loaded on designer, non-toxic, degradable, layered double hydroxide (LDH) clay nanosheets. Once loaded on LDH, the dsRNA does not wash off, shows sustained release and can be detected on sprayed leaves even 30 days after application. We provide evidence for the degradation of LDH, dsRNA uptake in plant cells and silencing of homologous RNA on topical application. Significantly, a single spray of dsRNA loaded on LDH (BioClay) afforded virus protection for at least 20 days when challenged on sprayed and newly emerged unsprayed leaves. This innovation translates nanotechnology developed for delivery of RNAi for human therapeutics to use in crop protection as an environmentally sustainable and easy to adopt topical spray.

It helps a bit but I’m puzzled by the description of BioClay as an alternative to RNAi in the first sentence because the last sentence has: “This innovation translates nanotechnology developed for delivery of RNAi … .” I believe what they’re saying is that LDH clay nanosheets were developed for delivery of RNAi but have now been adapted for delivery of dsRNA. Maybe?

At any rate this paper is behind a paywall.

Nanoremediation to be combined with bioremediation for soil decontamination

There’s a very interesting proposal to combine nanoremediation with bioremediatiion (also known as, phytoremediation) techniques to decontaminate soil. From a June 10, 2016 news item on Nanowerk,

The Basque Institute of Agricultural Research and Development Neiker-Tecnalia is currently exploring a strategy to remedy soils contaminated by organic compounds containing chlorine (organochlorine compounds). The innovative process consists of combining the application of zero-iron nanoparticles with bioremediation techniques. The companies Ekotek and Dinam, the UPV/EHU-University of the Basque Country and Gaiker-IK4 are also participating in this project known as NANOBIOR.

A June 10, 2016 Elhuyar Fundazioa news release, which originated the news item, provides more detail about the proposed integration of the two techniques,

Soils affected by organochlorine compounds are very difficult to decontaminate. Among these organochlorine compounds feature some insecticides mainly used to control insect pests, such as DDT, aldrin, dieldrin, endosulfan, hexachlorocyclohexane, toxaphene, chlordecone, mirex, etc. It is a well-known fact that the use of many of these insecticides is currently banned owing to their environmental impact and the risk they pose for human health.

To degrade organochlorine compounds (organic compounds whose molecules contain chlorine atoms) present in the soil, the organisations participating in the project are proposing a strategy based on the application, initially, of zero-iron nanoparticles [also known as nano zero valent iron] that help to eliminate the chlorine atoms in these compounds. Once these atoms have been eliminated, the bioremediation is carried out (a process in which microorganisms, fungi, plants or enzymes derived from them are used to restore an environment altered by contaminants to its natural state).

The bioremediation process being developed by Neiker-Tecnalia comprises two main strategies: biostimulation and bioaugmentation. The first consists of stimulating the bacteria already present in the soil by adding nutrients, humidity, oxygen, etc. Bioaugmentation is based on applying bacteria with the desired degrading capability to the soil. As part of this process, Neiker-Tecnalia collects samples of soils contaminated by organochlorine compounds and in the laboratory isolates the species of bacteria that display a greater capacity for degrading these contaminants. Once the most interesting strains have been isolated, the quantity of these bacteria are then augmented in the laboratory and the soil needing to be decontaminated is then inoculated with them.

Bank of effective strains to combat organochlorines

The first step for Neiker-Tecnalia is to identify bacterial species capable of degrading organochlorine compounds in order to have available a bank of species of interest for use in bioremediation. This bank will be gathering strains collected in the Basque Country and will allow bacteria that can be used as a decontaminating element of soils to be made available.

The combining of the application of zero-iron nanoparticles and bioremediation constitutes a significant step forward in the matter of soil decontamination; it offers the added advantage of potentially being able to apply them in situ. So this methodology, which is currently in the exploratory phase, could replace other processes such as the excavation of contaminated soils so that they can be contained and/or treated. What is more, the combination of the two techniques makes it possible to reduce the decontamination times, which would take much longer if bioremediation is used on its own.

There is a NANOBIOR webpage here.

For the curious I have two 2012 posts that provide some very nice explanations by Joe Martin, then a Master’s student in the University of Michigan’s Public Health program,: Phyto and nano soil remediation (part 1: phyto/plant) and Phyto and nano soil remediation (part 2: nano).