Sicily: “Tomato Fruit Blotch Virus” (ToFBV) – is threatening tomatoes


Sicily: “Tomato Fruit Blotch Virus” (ToFBV) – is threatening tomatoes

There is some concern for Sicilian tomato productions as, despite the fact that they have not yet recovered from the damage caused by ToBRFV, they might have to face a new problem in the form of the “Tomato Fruit Blotch Virus” (ToFBV – Blunervirus solani), an insidious disease that can be easily mistaken for the Tobamovirus and therefore treated as such, leading technicians and producers astray. Once again, just like it happened for ToBRFV, it was virologist and professor Walter Davino who spread the news during a convention held a few days ago in Ragusa (Sicily). Davino is one of the global leading experts in the field.

How the ToBFV looks on tomatoes

“ToFBV, or Blunervirus solani, is a new disease we have found in the Ragusa territory. This pathogen was identified for the first time in 2018 in the Fondi area (Lazio) and has not affected us so far,” reported Davino.

Professor Walter Davino

“This is worrying, as the virus can cause quite a lot of damage. It is a peculiar pathogen as we do not know it well and, as there is little information available at international as well, there is not much we can do at the moment.”

How ToFBV spreads

“What we know about this virus is that it is insidious, as plants show no symptoms until the berries change their color, meaning they can no longer be commercialized. This, in turn, means the damage is total and that the entire production is lost. The other thing we know is that it spreads via a well-known mite – Aculopis lycopersici – which is widespread in Sicily.”

Video interview
https://www.youtube.com/embed/S550rzroLwg

“I would also like to add that there are no resistant nor tolerant plants, so all we can do is follow the usual prophylaxis to contain the pathogen in our area, plus we must make every effort to find means suitable to contain the disease.”

Spreading of the virus

The news about the presence of TiBRFV in Sicily was given in 2019, always by Professor Favino. Operators are asked not to jump to conclusions to avoid speculation.

* The images contained in this article were kindly provided by Professor Walter Davino.

Publication date: Mon 29 Jan 2024

Climate smart agriculture can lead to ‘triple wins’ for farmer


Climate smart agriculture can lead to ‘triple wins’ for farmer

January 29, 2024 

Anna Page 

How climate smart agriculture can lead to ‘triple wins’ for farmers threatened by climate change

Image: Pexels

Global food consumption is predicted to increase by 51% by 2050. This is a profound challenge for our agrifood systems, which will only be made harder by the increased pressures of climate change on food security. In addition, agriculture is not just impacted by climate change; it is also a significant source of the greenhouse gas emissions driving climate change.

On the surface it may appear that these three challenges – the need for increased production, increased resilience, and reduced emissions – are incompatible. How can we increase food production without increasing emissions? Will the changes required to make agriculture more resilient impact productivity?

Climate Smart Agriculture (CSA) is an approach to agriculture designed to address all three challenges together, in an integrated way. CSA practices are not just better for the planet, but can increase productivity and provide increased security to the 3.8 billion people today living in households whose livelihoods depend to some degree on agriculture.

CSA doesn’t describe a single method but is rather a suite of traditional and modern knowledge and technologies that are better for farmers and the environment. The challenges faced by farmers and the feasibility of each solution will vary globally. Therefore, CSA doesn’t take a one size fits all approach, instead applying relevant best practices in local contexts. Not every individual practice recommended under CSA will provide improvements to all three of the challenges being targeted. Combining these practices can lead to the ‘triple win’ of increasing productivity, building resilience, and reducing emissions.

Below are some examples of practices that are encouraged in CSA:

Intercropping

Intercropping is growing two or more different crops in close proximity. There are multiple types of intercropping that involve different combinations, arrangements, and sowing time of crops. Different types of intercropping can bring different benefits. The benefits compared to monocultures can include reduced pests, improved yield, and improved soils.

Push-pull

Push-pull is a type of intercropping where repellent species are grown in proximity to the cash crop, to ‘push’ away pests, while attractive species are grown around the perimeter of the field to ‘pull’ the pests away. This can reduce the requirements for pesticides, saving money for the farmer and promoting biodiversity in the surrounding environment.

Crop rotations

Crop rotation involves growing different crops over sequential years in the same field, instead of growing the same crop in the same place for multiple years. This prevents crop-specific pests from establishing over multiple years and improves soil health.

Cover crops, catch crops and green manures

Growing non-cash crops in crop rotation with cash crops can improve the soil and help control weeds. Cover crops cover the soil between cash crops, smothering weeds and preventing soil erosion. Catch crops prevent nutrient losses through run off and leaching. Green manures capture nutrients, such as nitrogen from the atmosphere and can then be dug into the soil. This can help reduce fertilizer usage which can contribute to emissions.

Manures and organic fertilizers

Both the production and use of fertilizers can produce significant emissions, but fertilizers are important for achieving high yields. Use of organic fertilizers rather than synthetic fertilizers and reducing the amount of fertilizer used through precision fertilizing, can reduce emissions while increasing yields.

Mulches

Using mulches to cover the soil conserves moisture and nutrients, regulates soil temperature and improve soil structure. This can contribute to resilience and yield and reduce fertilizer requirements.

Conservation tillage

Conservation tillage, also known as minimum tillage, disturbs the soil as little as possible, leaving the residue from previous years crop in the field (often defined as a minimum of 30% of the soil left covered in residues). This helps prevent soil erosion, improve nutrient cycling and conserve nutrients and water.

Resistant varieties

Certain crops and varieties of crops have resistance to pests or enhanced tolerance to environmental stressors such as heat, drought, salinity and flooding. Using these varieties will increase resilience to climate change and reduced pesticide use.

Discover practical advice about climate smart agriculture

You can browse all the content in CABI’s PlantwisePlus Knowledge Bank recommending these CSA practices here

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Plant warfare: The crucial function of Nrc proteins in tomato defense mechanisms


Plant warfare: The crucial function of Nrc proteins in tomato defense mechanisms

by Boyce Thompson Institute

Credit: CC0 Public Domain

In the fascinating world of plant biology, a study recently featured on the cover of The Plant Journal has been turning heads. The research delves into the intricate defense mechanisms of tomatoes against the notorious bacterial pathogen Pseudomonas syringae pv. tomato (Pst). It’s a classic tale of nature’s arms race: As pathogens evolve to outsmart plant defenses, plants counter with more sophisticated immune responses.

The study is based on research conducted by scientists in Dr. Greg Martin’s lab at the Boyce Thompson Institute (BTI). Central to the study are proteins called Nucleotide-binding leucine-rich repeat receptors (NLRs), the plant equivalent of immune system warriors. They recognize and respond to pathogen attacks, triggering a series of defense mechanisms. Among these are the helper NLRs, Nrc2 and Nrc3, which work in concert with the tomato NLR Prf and its partner kinase, Pto, in a well-orchestrated defense against Pst.

The groundbreaking aspect of this research lies in its exploration of the roles of Nrc2 and Nrc3. Using CRISPR technology, the scientists created tomato mutant plants lacking these NLRs. While these mutants appeared normal under typical conditions, they exhibited increased susceptibility to Pst, similar to plants lacking the Prf protein.

“This finding was pivotal, highlighting the indispensable role of Nrc2 and Nrc3 in the tomato immune response,” noted Dr. Ning Zhang, a post-doctoral researcher at BTI and first author of the study.

One of the most intriguing outcomes of the research is understanding how Nrc2 and Nrc3 fit into the overall defense system. They seem to act upstream in the signaling cascade that leads to programmed cell death—a critical component of the plant’s immune response. This places them as essential intermediaries of the complex network of plant immunity.

The attention to Zhang’s research is a validation of its significance. “I’m thrilled that our discoveries on the workings of helper NLRs received prominent coverage in The Plant Journal,” she remarked. “Our work sheds light on how plants defend themselves—a topic of immense importance in agriculture.”

In essence, the research by Zhang and colleagues isn’t just a story of scientific discovery; it’s a roadmap for future innovations in crop resilience. “By unraveling the roles of helper NLRs like Nrc2 and Nrc3, we are a step closer to developing crops that can better withstand the challenges posed by pathogens, helping ensure food security and agricultural sustainability,” said Zhang.

More information: Ning Zhang et al, Helper NLRs Nrc2 and Nrc3 act codependently with Prf/Pto and activate MAPK signaling to induce immunity in tomato, The Plant Journal (2023). DOI: 10.1111/tpj.16502

Journal information: The Plant Journal 

Provided by Boyce Thompson Institute 


Explore further

Two plant immune branches more intimately connected than previously believed

Africa: New rice lines offer Rice Yellow Mottle Virus (RYMV) protection


Africa: New rice lines offer Rice Yellow Mottle Virus (RYMV) protection

JANUARY 11, 2024

 Editors’ notes

by Arne Claussen, Heinrich-Heine University Duesseldorf

Various rice plants, both control plants and mutants, between three and four weeks after inoculation. Credit: IRD / Laurence Albar

Rice yellow mottle virus (RYMV) is responsible for high crop losses in Africa, particularly among small-scale farmers. A research team has now produced rice lines that are resistant to the disease by means of genome editing.

The rice varieties, the development of which the team describes in Plant Biotechnology Journal, are a preliminary step toward being able to generate resistant locally adapted elite varieties for small-scale food producers in Africa.

RYMV is an RNA virus spread by beetles and direct leaf-to-leaf contact. In Africa, where the majority of producers farm plots of land barely one hectare in size, between ten and one hundred percent of the rice harvests are regularly lost to this virus. This makes it a life-threatening problem for the poorest farmers.

There is no effective protection against the virus. “The only real protection is to develop rice varieties that possess a resistance gene against RYMV, which would make the plant invulnerable,” says Dr. Yugander Arra, lead author of the study now published in Plant Biotechnology Journal.

A research team from the Institute for Molecular Physiology at HHU (headed by Professor Dr. Wolf B. Frommer) and the Institut de recherche pour le développement (IRD) in Montpellier, France, has developed such resistant rice lines.

Three resistance genes are currently known; mutations in just one gene, RYMV1, 2, and 3, are sufficient to achieve resistance. The resistant form rymv2 occurs in poor-yielding African rice (Oryza glaberrima) varieties. RYMV2, also known as CPR5.1, encodes an essential protein from the pores of the cell nucleus.

In the model plant Arabidopsis thaliana, the loss of the only gene copy of CPR5 results in a broad spectrum of resistance to viruses, bacteria, and fungi. However, growth is severely restricted; the plants exhibit spontaneous lesions and produce low yields. So, it was important to test whether rymv2 resistance could be transferred to other rice varieties without negative consequences.

In Africa, other high-yield rice varieties based on the Asian species Oryza indica are mainly used, and these do not have the resistance gene. Inserting the relevant gene is, however, not a particularly promising approach as the descendants of such “inter-species” hybrids are highly sterile and, therefore, cannot reproduce and pass on the resistance easily.

Using the CRISPR/Cas genome editing method, the research group has now shown that mutations of the RYMV2 gene can be produced in an Asian rice variety that make it resistant to the virus in a similar way to the African form. In the next step, the aim is to edit relevant African elite varieties in the same way to make them available to African small-scale producers. Helping these farmers is the goal of the international research consortium “Healthy Crops,” which is headed by HHU.

Plants have hereditary mechanisms that were useful for survival in the early days of evolution but which are now more likely to be harmful. Maize is a good example of this: A gene causes the kernels to be aborted when drought conditions prevail at the time of fertilization. This trait caused by the gene was good for the wild perennial forebears of today’s maize plants but has a detrimental effect on the yield of the annual plants now used in agriculture.

The situation is similar with the rice examined here. Professor Frommer says, “This resistance trait is attributable to the loss of a gene function that is not essential. If we switch the gene off completely, the plants behave normally. However, as a result of the loss of the gene function, they are resistant to the virus.”

Dr. Eliza Loo, Healthy Crops Group Leader, adds, “It is so to speak an archetype, which was useful for its forebears, but which now leads to devastating crop losses in periods of drought. It would appear expedient to switch this gene off and it has no obvious side effects.”

Surprisingly, neither switching off the closely related CPR5.2 gene nor the two genes RYMV 2 and CPR5.2—at least under greenhouse conditions—leads to impairments. It is also noteworthy that the loss of CPR5.2 does not lead to RYMV resistance. Everything indicates that editing the RYMV2 gene is a promising approach to combating rice disease in Africa.

More information: Yugander Arra et al, Rice Yellow Mottle Virus resistance by genome editing of the Oryza sativa L. ssp. japonica nucleoporin gene OsCPR5.1 but not OsCPR5.2, Plant Biotechnology Journal (2023). DOI: 10.1111/pbi.14266

Journal information: Plant Biotechnology Journal 

Provided by Heinrich-Heine University Duesseldorf 


Explore further

Genome editing used to create disease-resistant rice

USA: Tar spot was confirmed in central Missouri cornfields in 2023


USA: Tar spot was confirmed in central Missouri cornfields in 2023

Problems ahead for 2024? Tar spot was confirmed in central Missouri cornfields; universities look for answers through DNA.

Picture of Mindy Ward

Mindy Ward

January 17, 2024

2 Min Read

A close up of tar spot on a corn leaf

PINNING DOWN DISEASE: Tar spot, a disease that generally does not like heat, is finding a way to survive. It’s moved south, and researchers are looking into its DNA to see exactly what is at work in Missouri cornfields.KIERSTEN WISE, BUGWOOD.ORG

Mandy Bish spent the early days of fall 2023 stopping at random cornfields in central Missouri looking for tar spot, and she found it about 90% of the time.

“It might have taken me four or five plants,” the University of Missouri Extension state plant pathologist explained, “but I could confirm it pretty rapidly.”

By season’s end, tar spot spread to an additional 25 additional counties in the state, bringing the grand total to 49 counties dealing with this fungal pathogen.

In most regions of the state, tar spot appeared later in the season, and yield losses were not observed. However, there were instances in northwest and northeast Missouri where yield losses occurred.

It boils down to environmental conditions and perhaps disease design.

Weather prompted early arrival

Bish’s phone started ringing in June 2023 with reports of tar spot in Missouri.

“I said it wasn’t tar spot because it was too early,” she said, “but I was wrong.”

During the MU Crop Management Conference in December, she explained how the risk of tar spot increases when cooler temperatures (minimum air temperature is less than 59.7 degrees F) and cooler dew-point temperatures (less than 55.6 degrees) combine over a window of time. And that was the scenario in the state for June when air and dew-point temperatures were about 6 degrees below the three-year average.

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However, July saw warmer temperatures, with some regions reaching triple digits. “This disease does not like heat, and it got hot,” Bish said. “The disease kind of stagnated.”

A map indicating movement of tar spot in Missouri

By mid- to late August, cooler temperatures returned with a little moisture from Mother Nature and irrigation pivots. Tar spot started spreading once again across Missouri cornfields.

“One thing we know is you have to have some moisture for disease progression,” Bish explained. “So just seeing it first, you don’t need moisture, but to have a progression of the disease, you need some moisture and that’s what happened.”

With environmental conditions out of many growers’ controls, university researchers are looking into others means to slow the spread of the tar spot, right down to its DNA.

Studying the genome of tar spot

The fungal pathogen Phyllachora maydis causes tar spot. However, with the rapid spread of the disease, Bish and university researchers are wondering if the pathogen is the same in all states. Are there types (or races) of the pathogen that are more adapted to thrive in Southern climates?

University researchers are working together to answer this question. Comparing DNA from different samples of the pathogen can help scientists understand and provide researchers with more information about tar spot across the Corn Belt.

Bish said the results may provide a launching pad for opportunities to improve management of this corn disease.

Read more about:Tar Spot

About the Author(s)

Mindy Ward

Mindy Ward

Editor, Missouri Ruralist

Mindy resides on a small farm just outside of Holstein, Mo, about 80 miles southwest of St. Louis.

After graduating from the University of Missouri-Columbia with a bachelor’s degree in agricultural journalism, she worked briefly at a public relations firm in Kansas City. Her husband’s career led the couple north to Minnesota.

There, she reported on large-scale production of corn, soybeans, sugar beets, and dairy, as well as, biofuels for The Land. After 10 years, the couple returned to Missouri and she began covering agriculture in the Show-Me State.

“In all my 15 years of writing about agriculture, I have found some of the most progressive thinkers are farmers,” she says. “They are constantly searching for ways to do more with less, improve their land and leave their legacy to the next generation.”

Mindy and her husband, Stacy, together with their daughters, Elisa and Cassidy, operate Showtime Farms in southern Warren County. The family spends a great deal of time caring for and showing Dorset, Oxford and crossbred sheep.

Digital Monitoring of Crop Pests Via Vibrational Signals


January 17, 2024 The Entomology Profession 0

The Insect Eavesdropper, a system that uses a contact microphone and minicomputer to analyze the vibrational signals of insects feeding on plants, took 1st Place in the 2023 ESA Antlion Pit, an innovation competition for entomology-related products and services. View the 2023 Antlion Pit presentation session here. (The video is cued to start with the Insect Eavesdropper presentation; skip back or ahead to see other segments.)

Last November at Entomology 2023 saw the return of the Antlion Pit, an innovation competition for entomology-related products and services. Six teams were selected to compete out of nine applications, with the “Insect Eavesdropper” team earning 1st Place and a $5,000 prize to invest in advancing their product, a system using a contact microphone and a minicomputer to detect and identify the vibrational signals of insects feeding on plants.

A system that uses a contact microphone and minicomputer to analyze the vibrational signals of insects feeding on plants took 1st Place in the 2023 ESA Antlion Pit, an innovation competition for entomology-related products and services. The creators of the Insect Eavesdropper are Emily Bick, Ph.D., BCE-Intern (left), assistant professor in the Department of Entomology at the University of Wisconsin-Madison, and Dev Mehrotra (right), master’s student in computer science working in Bick’s lab at UW.

The creators of the Insect Eavesdropper are Emily Bick, Ph.D., BCE-Intern, assistant professor in the Department of Entomology at the University of Wisconsin-Madison, and Dev Mehrotra, master’s student in computer science working in Bick’s lab at UW.

Entomology Today connected with Bick and Mehrotra for a Q&A to learn more about Insect Eavesdropper and its development.

Entomology Today: How did you both get started on developing the Insect Eavesdropper? What inspired this pursuit?

Bick and Mehrotra: When Emily visited a sugarcane farm in Indonesia, she was challenged to develop a sensor to directly measure insects boring within plants, rather than monitoring adult immigration and using degree days to predict when boring larvae were active. After looking into existing technologies such as laser vibrometers, electric stethoscopes, and other potential methods, Dev built the very first Insect Eavesdropper.

Can you summarize what the Insect Eavesdropper does and how it works?

The Insect Eavesdropper is a contact microphone strategically clipped to or stuck on a plant. A minicomputer starts, stops, and saves a recording of insects chomping on the leaves, sucking on the plant, boring through its tissue, or chewing on the roots. The recording is pre-processed and the feeding “event” is extracted and then run through a machine learning algorithm for species identification. Thus far, the Insect Eavesdropper can detect, identify to species, and count insects that are directly feeding on plants.

What are the likely potential applications for the Insect Eavesdropper? Who might be the primary customers for it as a commercial product?

The Insect Eavesdropper addresses the unmet need for cost-effective and accurate digital monitoring of insects as they directly feed on crops. The technology’s potential use cases are twofold:

  1. Subscription to data, analysis, and alerts from a network of Insect Eavesdroppers continuously monitoring sentinel crops. This method mimics trapping networks or predictions from degree days in an accurate, efficient, and cost-effective way.
  2. The mobile version of the Insect Eavesdropper, termed “Rambling Eavesdropper,” which crop consultants, growers, extension folk, and researchers can use to sample crops for pests via non-destructive, efficient methods.

We highlight the Eavesdropper ecosystem below, with each type of user on the left, the sensor flow within the gray boxes, and leaving the decision making up to the better-informed stakeholder, on the left.

Flowchart running left to right. At left are a tractor logo labeled Agtech, a sweepnet labeled Consultants, and a farmer icon labeled Growers. Agtech and Consultants have arrows labeled Subscribe pointing the top row of the flowchart, starting with Sensor Network followed by Continuous Monitoring, under a header of Insect Eavesdropper. Consultants and Growers have arrows labled Purchase sensor, Alert subscription, pointing to the bottom row of the flowchart, starting with Mobile Sensor followed by Pest snapshot, under a header of Rambling Eavesdropper. The rows then converge to Analytics and Alerts, followed by an icon at end of a person with a light bulb icon. Across the top, stages are labeled Sensor deployment, Data collection, Analysis, Insight, and Ag Decisions.
The Insect Eavesdropper, a system that uses a contact microphone and minicomputer to analyze the vibrational signals of insects feeding on plants, took 1st Place in the 2023 ESA Antlion Pit, an innovation competition for entomology-related products and services. The creators of the Insect Eavesdropper envision it being used as both a sensor network for continuous monitoring or a mobile, handheld sensor for spot-checking crops for pests. (Figure courtesy of Emily Bick, Ph.D., BCE-Intern, and Dev Mehrotra)

What stage are you in now in developing and testing the Insect Eavesdropper? What challenges do you currently face?

On the hardware, Dev has led the efforts in Emily’s lab to successfully develop two prototypes for the Insect Eavesdropper and Rambling Eavesdropper. The former is a stationary version, continuously monitoring insects similar to Malaise traps or sticky cards; the latter is version that can be carried around a field, mimicking a sampling tool like a sweep net.

We received an accelerator grant from the Wisconsin Alumni Research Foundation to “unwire” the Insect Eavesdropper, using a module such as LoRa, Bluetooth, or Wi-Fi for data transmission. On the software, we are building a toolkit to make the sensor more accessible to anyone, regardless of programing capability. This will allow a broad variety of potential users to independently work with the Insect Eavesdropper.

Functionally, we are formalizing the machine learning algorithms that identify species, adding to our species library, and working through density estimates based on feeding events. Additionally, we are handing the Insect Eavesdropper to researchers working across the world, trying to find the limits of the Insect Eavesdropper as well as externally validate the sensor.

How did competing in and taking 1st Place in ESA’s Antlion Pit competition advance your work on the Insect Eavesdropper?

The Antlion Pit competition helped spread the word about the Insect Eavesdropper and its potential. It was exciting to expose our idea to scrutiny across the entomology community. The Antlion Pit competition provided us with valuable feedback that will shape the Insect Eavesdropper for years to come.

For those interested in the Insect Eavesdropper, where can they learn more, and what should we be on the lookout for next from you?

To learn more, please visit www.bicklab.com/eavesdropper. If academics are interested in applying the Insect Eavesdropper to a difficult entomological problem, they should reach out to Emily at ebick@wisc.edu. If industry folks are interested in potentially licensing the method, they should reach out to Emily Bauer at the Wisconsin Alumni Research Foundation at emily@warf.org. Everyone else should keep your eyes peeled for our upcoming publications.

The Insect Eavesdropper, a system that uses a contact microphone and minicomputer to analyze the vibrational signals of insects feeding on plants, took 1st Place in the 2023 ESA Antlion Pit, an innovation competition for entomology-related products and services. It also received an accelerator grant from the Wisconsin Alumni Research Foundation to incorporate a module for wireless data transmission.

Learn More

Insect Eavesdropper

Antlion Pit Competition, Entomological Society of America

Fossils of first photosynthesising bacteria


Fossils of first photosynthesising bacteria

January 4, 2024 Matthew Ward Agius Matthew Agius is a science writer for Cosmos Magazine.

Photosynthesis first evolved in living organisms at least 1.75 billion years ago, according to a new study into ancient organisms by a team of Belgian biologists.

The updated timescale is the result of their study into fossilised cyanobacteria (sometimes referred to as ‘blue-green algae’) sourced from the McArthur Basin, which stretches from the northern fringe of Australia along the Arafura Sea and Gulf of Carpentaria.

The group from the University of Liège believe they’ve found in microfossils of Navifusa majensis the “oldest direct evidence” of specialised biological structures – thylakoid membranes – which are essential to oxygenic (oxygen-producing) photosynthesis.

A photomicrograph of a modern-day cyanobacterium. Credit: N Nehring via Getty Images

Photosynthesis is the chemical process by which plants and some single-celled organisms create energy. In the cells of most photosynthesising organisms, carbon dioxide and water are converted using light energy into sugar and oxygen.

Typically, this occurs at sites in plant cells called chloroplasts. Within these structures are thylakoids, which house the green pigment chlorophyll that absorbs sunlight for use in photosynthesis.

Unlike plants, cyanobacteria don’t possess chloroplasts.

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They do have thylakoids, which is why evolutionary biologists think these single-celled organisms were incorporated into complex plant cells as chloroplasts.

But not all cyanobacteria produce their energy using thylakoids – the genus Gloeobacter instead photosynthesises via light-capturing protein structures in their plasma membrane.

Understanding cyanobacteria evolution could help scientists understand a major change in Earth’s history.

Oxygen-producing photosynthesis is the likely cause of a major historic spike of oxygen in Earth’s atmosphere about 2.4 billion years ago – vital for the development of life on our planet. Scientists working across several disciplines have struggled to pinpoint the precise cause of this so-called Great Oxidation Event, however the Liège study published today in the journal Nature at least pushes the dial backwards.

Led by PhD student Catherine Demoulin and Dr Emmanuelle Javaux, the research team studied N. majensis microfossils obtained from rock formations in the Northwest Territories in Canada, the Democratic Republic of Congo and the McDermott Formation in the Northern Territory, Australia. Of these, the McDermott samples were the oldest – dating back 1.75 billion years – providing a new minimum timepoint for the emergence of thylakoid-containing cyanobacteria.

Aerial photo of stromatolites
Stromatolites formed by billion-year-old cyanobacteria at the Hamelin pools in Western Australia. Credit: Intst via istock/Getty Images Plus

In their study, they note the specimens were highly preserved, allowing the arrangement of thylakoid membranes to be microscopically observed.

“Thylakoids represent direct ultrastructural evidence for oxygenic [oxygen-producing] photosynthesis,” they write.

“The discovery of preserved thylakoids within N. majensis reported here provides direct evidence for a minimum age of about 1.75 Ga for the divergence between thylakoid-bearing and thylakoid-less cyanobacteria.

“By probing the older fossil record, it may also allow testing of the hypothesis that the emergence of thylakoid membranes may have contributed to the rise in oxygen around the GOE, and to the permanent oxygenation of the early Earth.”

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Originally published by Cosmos as Biologists pinpoint fossils of first photosynthesising bacteria

Kenya: Sustainable biopesticides for horticulture


Kenya: Sustainable biopesticides for horticulture

In recent years, there has been a growing complexity of phytosanitary challenges in the horticulture and floriculture sectors due to the increased global movement of agricultural produce. The overreliance on synthetic pesticides poses threats to quality and international competitiveness. The Embassy of the Kingdom of the Netherlands held a workshop to promote biopesticides at the 2023 Naivasha Horticulture Fair as a sustainable solution to evolving sanitary and phytosanitary standards.

In recent years, phytosanitary-related challenges have become more complex, mainly due to the increased movement of agricultural produce and regulated materials from one country to another. Kenya is no exception. Some of these pests and diseases have the capacity to directly affect consumers, damage crops, and the natural environment. Their impact is widespread, given that most of these pests and diseases are transboundary. The burden to control them mainly falls on the producers. This directly affects the quality of produce and ultimately competitiveness of Kenyan produce on the international market. Overreliance on synthetic pesticides has made this worse due to heightened demands on the use of pesticides that are in alignment with the phytosanitary standards for the import and export markets. Sanitary and Phytosanitary Standards (SPS) measures are now a strategic tool for developing and differentiating markets, increasing market access, coordinating the quality and safety of food systems, and defining market niches for export products.

For sustainability, the safe use of chemicals in production is key to meeting the SPS standards. It is towards this goal, that the Embassy of the Kingdom of the Netherlands, together with partners, held a workshop during the 20th edition of the Naivasha Horticultural fair in Naivasha- Nakuru County, where stakeholders shared experiences on the use of bio solutions, regulation policies and the role that all play in enabling the transition to the use of biopesticides, as a solution to changing Sanitary and Phytosanitary requirements in the horticulture and Floriculture sectors.

Bart Pauwels, Agriculture Counsellor at the Embassy of the Kingdom of the Netherlands, opened the workshop forum by highlighting the changing demands from government to government for stringent sanitary phytosanitary standards, that is informed by the changing environment for production and growing demands by consumers. “Pests are becoming more resistant to pesticides, and the effects of climate change are worsening the production environment in agriculture. It is therefore imperative for the sector to adapt to these changes and seek safer solutions to addressing the pest and disease menace in a bid to safeguard trade.”

Regulatory agencies in Kenya, such as Kenya Plant Health Inspectorate Service (KEPHIS), Kenya Flower Council (KFC), Pest Control Products Board (PCPB), and IBMA (International Biocontrol Manufacturers Association), have been working with growers, researchers, and agro-chemicals suppliers to ensure that the pesticides used in production are in alignment with the phytosanitary standards for the import and export markets.

According to Sarah Wambugu, Senior Pesticide Registration Officer- Pest Control Products Board (PCPB), “With the changing SPS requirements, there has been increased interest in licensing biocontrol solutions that aim to reduce the overuse of synthetic chemicals.”

It was noted that production and commercialization of bio-pesticides is hampered by lengthy and costly registration processes and inadequate production, distribution and storage infrastructure. The situation is compounded by a lack of awareness to the public and the proliferation of adulterated products. This is a challenge in the Bio-control space since most products have a limited shelf life, hence making it very expensive for many manufacturers to introduce biopesticides.

To address this, there was a proposal to PCPB to consider providing temporary permits for products that have been approved in other key markets. This way, more producers in the Horticulture and Floriculture sectors will be able to access the biopesticides solutions. Sarah added that PCPB makes exemptions in special cases, such as emergencies from pest and disease outbreaks, and is in the process of exploring other opportunities to hasten the approval process.

Kenya’s floriculture sector is advanced with reference to regulatory systems. According to John Njenga, Scheme Manager- Kenya Flower Council, the council is working towards compliance by its members to global standards and has set 2025 as the year to attain full compliance. “By becoming members of Kenya Flower Council, we monitor our members’ usage of chemicals through data collection and audits undertaken to make sure that compliance is achieved. Through compliance and accreditation by the council, It becomes easier for them to access all markets. However, the cost of transition from synthetic to some of the biopesticides is very high. This poses a risk of adoption by the producers. There is a need to seek ways to make bio-control solutions affordable and accessible.”

Farmers who have started to use bio-protection solutions are already noting positive changes in the quality of their produce. Amala Munyendo – a farm manager, noted that by using biopesticides, their use of synthetic chemicals has remarkably reduced the prevalence of pests, too. On the other hand, Avinash Mokate highlighted that, at the onset of using bio solutions, the results are achieved at a much slower rate, but once the soil gains its health, the yields increase, and the maintenance cost also reduces. “However, it’s important to note that the efficacy of biopesticides can vary depending on factors like crop type, pest species, and local environmental conditions. Integrated pest management (IPM) strategies that combine various pest control methods, including biopesticides, synthetic pesticides, and cultural practices, are often the most effective way to address pest challenges while meeting SPS standards.

Source: agroberichtenbuitenland.nl

Publication date: Wed 17 Jan 2024

Endophytic bacteria to improve tomato plants immune responses managing root-rot disease


Endophytic bacteria to improve tomato plants immune responses managing root-rot disease

Around the world, a variety of crops, including tomatoes, suffer serious economic losses due to the Rhizoctonia root-rot disease. Herein, Bacillus velezensis, Bacillus megaterium, and Herpaspirillum huttiense isolated from strawberry (Fragaria chiloensis var. ananassa) plants were pragmatic as plant growth promotors for battling the Rhizoctonia root rot disease and bringing about defense mechanisms as well as growth promotional strategies in tomato plants. These endophytic bacteria demonstrated potent antifungal activity against R. solani in vitro along in vivo.

Data explained that the isolated endophytic bacteria could produce Indole acetic acid, Gibberellic acid GA, and siderophore as well as solubilize phosphate in the soil. The consortium of (Bacillus velezensis, Bacillus megaterium, and Herpaspirillum huttiense) increased the protection % against Rhizoctonia infection by (79.4%), followed by B. velezensis by (73.52%), H. huttiense by (70.5%), and B. megaterium by (67.64%), respectively. There was an increase in soluble proteins and carbohydrates in infected plants treated with a consortium of endophytic bacteria by 30.7% and 100.2% over untreated infected plants, respectively.

Applying endophytic bacteria either alone or in combination lowered the level of malondialdehyde MDA and hydrogen peroxide H2O2 and improved the activities of antioxidant enzymes in both infected and uninfected plants. Also, bacterial endophytes have distinctive reactions regarding the number and concentrations of isozymes in both infected and uninfected plants. It could be recommended the commercial usage of a mixture of targeted bacterial endophyte strains as therapeutic nutrients against Rhizoctonia root-rot disease as well as plant growth inducer.

Abbas, M.M., Ismael, W.H., Mahfouz, A.Y. et al. Efficacy of endophytic bacteria as promising inducers for enhancing the immune responses in tomato plants and managing Rhizoctonia root-rot disease. Sci Rep 14, 1331 (2024). https://doi.org/10.1038/s41598-023-51000-8

Click here to read the complete paper

Publication date: Wed 17 Jan 2024

Targeted pest control with RNA spray


Targeted pest control with RNA spray

by Désirée Schulz, Fraunhofer-Gesellschaft

Green peach aphids carry various yellowing viruses that lead to high losses in sugar beet yields. Credit: Leonie Graser/Fraunhofer-Gesellschaft

Protecting plants efficiently against pests without harming other organisms—this is the objective of the joint research project ViVe_Beet, which is coordinated by the Julius Kühn Institute (JKI). Scientists from the JKI Institute for Plant Protection in Field Crops and Grassland, the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Sugar Beet Research (IfZ) are involved in the project.

The strategy adopted by the project partners involves the use of customized double-stranded RNA molecules, incorporated into a suitable formulation. This formulation is then applied through conventional application methods to protect sugar beets from yellowing viruses in the future.

Application of synthetic chemical insecticides and pesticides in agriculture has a negative impact on insect diversity and bee health. To avoid such harm, the EU phased out approval of systemically effective neonicotinoids in 2019. However, this has led to new issues in agriculture, particularly because green peach aphids (Myzus persicae), among the insects displaying high resistance to synthetic chemical insecticides, have proven exceptionally challenging to manage.

These aphids transmit several yellowing viruses—affecting sugar beets in particular—leading to enormous losses in sugar beet harvests. “We’re actually speaking of a 20% to 50% loss in yield due to the viruses alone,” says Maurice Pierry who has been supporting the ViVe_Beet project at the Fraunhofer IME Bioresources branch in Gießen from the start.

New approach to pest control: RNA interference (RNAi)

The scale of the issue means that new approaches are urgently required to ensure sustainable and efficient control of the aphids. Fraunhofer IME and its project partners JKI and IfZ have chosen a biological, species-specific approach and are working together to control these aphids with the help of RNA interference (RNAi).

Targeted pest control with RNA spray
During the RNA interference (RNAi) process, the double-stranded RNA (dsRNA) is cut into small interfering RNA (siRNA) by the Dicer enzyme. The siRNA is incorporated into the RISC enzyme complex serving as the template for matching sequences which are then degraded by RISC. Credit: Maurice Pierry/Fraunhofer-Gesellschaft

RNAi is a natural immune response of the hosts to the foreign genetic material of viruses, which is often present in the form of double-stranded RNA (dsRNA). Pierry explains, “Viruses have genetic material in the form of RNA. When RNA enters the cell of a living being (i.e., an insect in our case), an enzyme called ‘Dicer’ chops it into smaller segments known as small interfering RNA (siRNA).

“They are then incorporated into the RNA induced silencing complex (RISC) and used as a template to degrade matching mRNA sequences. If we select these dsRNAs so that they match a crucial gene of the insect, you can induce the organism to control itself effectively via its own RNAi system.”

From lab tests to the field

At the start of the project, which is scheduled from October 2021 to September 2024, potentially effective genes and their base sequences had to be identified. This was followed by biological methods to produce dsRNA specifically adapted to these base sequences. Pierry states, “To start with, we had to identify a gene that has an effect when silenced with the RNA interference mechanism. Effects vary from molting problems and a drop in offspring to increased mortality of the pests. After conducting a number of tests, we managed to identify several genes that cause high mortality in the aphids when silenced. This was the first major milestone.”

In a second step, the Fraunhofer IME scientists had to create a formulation that would protect the double-stranded RNA molecule from environmental factors such as temperature, humidity, UV rays and RNA-degrading enzymes until it reaches its destination, e.g., in the aphids’ intestines, where it is absorbed by the cell. “We have also been successful in this area. This means that our dsRNA is protected by a formulation that boosts the effect and has prolonged longevity,” says Pierry.

In the meantime, the researchers have embarked on the third step: The first spray trials directly on the target plant. “We have developed an RNA spray method and tested it in greenhouse spray trials. So far, we have achieved a mortality rate of 70% and a reduction in population size. These are great results,” says Pierry.

The final step will involve field trials including all previously excluded environmental factors. These will be carried out by JKI and the IfZ next summer.

Selective plant protection agents are harmless to other organisms

The innovative approach of the ViVe_Beet project can potentially lead to the development of new, environmentally friendly, selective plant protection agents, as the specific and natural molecules can be used not only to control insects but also viruses or fungi.

“This method is special as the specifically adapted dsRNA affects the target organism, in this case, the green peach aphids, but no other organisms such as humans or beneficial insects like bees,” says Pierry.

This new method of pest control raises hope for sustainable plant protection and has a high potential for future applications.

Provided by Fraunhofer-Gesellschaft 


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