Tag Archives: plant diseases

Mushroom compost as a biobased nanocarrier for curing plant diseases

Scientists in Europe have just cured a plant disease Esca (fungi that destroy grapevines) for the first time ever. A May 22, 2019 news item on Nanowerk announces the research success,

Plant diseases, though a normal part of nature, can have disastrous effects in agriculture. They reduce food for people and revenues in rural areas. In the worst cases they result in hunger and starvation, as many famines in history show. About 16% of all crops are lost to plant diseases each year across the world.

The Max Planck Institute for Polymer Research in Mainz has just delivered a double novelty to the scientific world: nanocarriers made of “waste”, which release drugs in a way that cured a plant disease for the first time.

Nanocarriers are very tiny degradable capsules that have been studied for medical applications in the last 30 years. These nanocapsules are considered the “magic bullet” to cure human cancer, because they discharge the drug directly to the targeted cells.

A May 20, 2019 BIOrescue project press release, which originated the news item, delves further into the research,

Treating plant diseases that have never been cured before

Thanks to the European research funds of the BIOrescue project, the researchers at the Max Plank Institute investigated the possibility to transpose the same principle to cure plant diseases. They have been testing these nanocapsules to treat ESCA, a fungi disease that affects 2 billion grapevine plants across the world for which there has not been a cure so far.
Dr Frederik Wurm, who is leading this research at Max Planck said “After two years of testing in our labs and then on Riesling vineyards in Germany, it looks like we have managed to reduce the symptoms of the disease. Further tests will confirm if this cure is a solution in the long term. If the effects are confirmed the same method can be extended potentially to any other disease in agriculture”.

“Circular” nanocarriers made of waste

The second novelty of these nanoscopic capsules is that they can be made of waste material – in this case used mushrooms compost.

“Normally nanocarriers are made of polymers based on fossil fuels. In the past, we have developed biobased nanocarriers made of lignin coming from the paper and pulp industry. But this is the very first time we try to develop them from agricultural residues, which makes them a truly “circular” product, from used plant fertiliser to plant cure. Nothing is going to be wasted!” said Wurm.

To obtain these tiny biodegradable capsules, the Max Planck researchers carried out a chemical conversion to transform the soluble lignin obtained after the pretreatment of used mushroom compost.

Afterwards the nanocarriers have been loaded with the drug that is usually sprayed on the plant with very limited effects. Thanks to the natural enzymatic degradation of the nanocarriers, the drug is released inside the plant in a controlled and progressive way. With this effective method the drug only targets the fungi, which destroy the plant from inside. Tests demonstrated that these nanocarriers are not toxic for the plants and do not reach the crop.

“Beyond the agricultural sector, the capsules have a myriad of other potential applications from food enhancement to pharmaceutical products. It’s only a matter of time until we find biobased nanocarriers available on the market for any of these uses” said Wurm.

Bio-based nanocarrier Courtesy: BIOrescue

You can find out more about the BIOrescue project here, including interesting facts such as this,

To satisfy consumer demand for mushrooms, European farmers use over three million tonnes of compost each year. Though the compost contains valuable organic components, it is only suitable for one to three mushroom harvests, and disposing of it creates significant economic and logistical problems for Europe’s farmers.

Apparently, this is is a ‘circular economy’ project. ‘Circular economy’ being one of the latest buzz terms. Let’s hope it graduates to something ‘beyond buzz’, as it were.

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.