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Archive for the ‘Host plant resistance’ Category

Climate change means farmers in West Africa need more ways to combat pests

by Loko Yêyinou Laura Estelle, The Conversation

worm on corn
Credit: Unsplash/CC0 Public Domain

The link between climate change and the spread of crop pests has been established by research and evidence.

Farmers are noticing the link themselves, alongside higher temperatures and greater variability in rainfall. All these changes are having an impact on harvests across Africa.

Changing conditions sometimes allow insects and diseases to spread and thrive in new places. The threat is greatest when there are no natural predators to keep pests in check, and when human control strategies are limited to the use of unsuitable synthetic insecticides.

Invasive pests can take hold in a new environment and cause very costly damage before national authorities and researchers are able to devise and fund ways to protect crops, harvests and livelihoods.

Early research into biological control methods (use of other organisms to control pests) shows promise for safeguarding harvests and food security. Rapid climate change, however, means researchers are racing against time to develop the full range of tools needed for a growing threat.

The most notable of recent invasive pests to arrive in Africa was the fall armyworm, which spread to the continent from the Americas in 2016.

Since then, 78 countries have reported the caterpillar, which attacks a range of crops including staples like maize and has caused an estimated US$9.4 billion in losses a year.

African farmers are still struggling to contain the larger grain borer, or Prostephanus truncatus Horn, which reached the continent in the 1970s. It can destroy up to 40% of stored maize in just four months. In Benin, it is a particular threat to cassava chips, and can cause losses of up to 50% in three months.

It’s expected that the larger grain borer will continue to spread as climatic conditions become more favorable. African countries urgently need more support and research into different control strategies, including the use of natural enemies, varietal resistance and biopesticides.

My research work is at the interface between plants, insects and genetics. It’s intended to contribute to more productive agriculture that respects the environment and human health by controlling insect pests with innovative biological methods.

For example, we have demonstrated that a species of insect called Alloeocranum biannulipes Montr. and Sign. eats some crop pests. Certain kinds of fungi (Metarhizium anisopliae and Beauveria bassiana), too, can kill these pests. They are potential biological control agents of the larger grain borer and other pests.

Improved pest control is especially important for women farmers, who make up a significant share of the agricultural workforce.

In Benin, for example, around 70% of production is carried out by women, yet high rates of illiteracy mean many are unable to read the labels of synthetic pesticides.

This can result in misuse or overuse of chemical crop protection products, which poses a risk to the health of the farmers applying the product and a risk of environmental pollution.

Moreover, the unsuitable and intensive use of synthetic insecticides could lead to the development of insecticide resistance and a proliferation of resistant insects.

Biological alternatives to the rescue

Various studies have shown that the use of the following biological alternatives would not only benefit food security but would also help farmers who have limited formal education:

  1. Natural predators like other insects can be effective in controlling pests. For example I found that the predator Alloeocranum biannulipes Montr. and Sign. is an effective biological control agent against a beetle called Dinoderus porcellus Lesne in stored yam chips and the larger grain borer in stored cassava chips. Under farm storage conditions, the release of this predator in infested yam chips significantly reduced the numbers of pests and the weight loss. In Benin, yams are a staple food and important cash crop. The tubers are dried into chips to prevent them from rotting.
  2. Strains of fungi such as Metarhizium anisopliae and Beauveria bassiana also showed their effectiveness as biological control agents against some pests. For example, isolate Bb115 of B. bassiana significantly reduced D. porcellus populations and weight loss of yam chips. The fungus also had an effect on the survival of an insect species, Helicoverpa armigera (Hübner), known as the cotton bollworm. It did this by invading the tissues of crop plants that the insect larva eats. The larvae then ate less of those plants.
  3. The use of botanical extracts and powdered plant parts is another biological alternative to the use of harmful synthetic pesticides. For example, I found that botanical extracts of plants grown in Benin, Bridelia ferruginea, Blighia sapida and Khaya senegalensis, have insecticidal, repellent and antifeedant activities against D. porcellus and can also be used in powder form to protect yam chips.
  4. My research also found that essential oils of certain leaves can be used as a natural way to stop D. porcellus feeding on yam chips.
  5. I’ve done research on varietal (genetic) resistance too and found five varieties of yam (Gaboubaba, Boniwouré, Alahina, Yakanougo and Wonmangou) were resistant to the D. porcellus beetle.

Next generation tools

To develop efficient integrated pest management strategies, researchers need support and funding. They need to test these potential biocontrol methods and their combinations with other eco-friendly methods in farm conditions.

Investing in further research would help to bolster the African Union’s 2021–2030 Strategy for Managing Invasive Species, and protect farmers, countries and economies from more devastating losses as climate change brings new threats.

Initiatives like the One Planet Fellowship, coordinated by African Women in Agricultural Research and Development, have helped further the research and leadership of early-career scientists in this area, where climate and gender overlap.

But much more is needed to unlock the full expertise of women and men across the continent to equip farmers with next generation tools for next generation threats.

Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.


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Why African farmers should balance pesticides with other control methods

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A gene from 28 million years ago protects today’s plants against caterpillars

Date:November 15, 2022Source:eLifeSummary:The defense mechanisms plants use to recognize and respond to a common pest — the caterpillar — has arisen from a single gene that evolved over millions of years, according to a new report.Share:

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The defence mechanisms plants use to recognise and respond to a common pest — the caterpillar — has arisen from a single gene that evolved over millions of years, according to a report published today in eLife.

The study finds that some plants, such as soybeans, have lost this protective gene over time, and suggests that breeding plants or genetically engineering them to reintroduce the gene could protect against crop failure.

The health status of a plant depends on the immune system it inherits. In plants, this means inheriting certain types of pattern recognition receptors that can recognise distinct pathogens and herbivore-derived peptides, and trigger an appropriate immune response.

“Inheriting the right types of pattern recognition receptors can allow plants to recognise threats and cope with diseases and pests,” explains lead author Simon Snoeck, postdoctoral researcher at the Department of Biology, University of Washington, US. ” Although we know many pest-derived molecules which activate immune responses in plants, our knowledge of how plants evolved the ability to sense new threats is limited.”

To address this gap, the team set out to define the key evolutionary events that allowed plants to respond to a common threat — the caterpillar. It was already known that species in a group of legumes — including mung beans and black-eyed peas — are uniquely able to respond to peptides produced from the mouths of caterpillars as they munch through plant leaves. So they looked at the genomes of this group of plants in depth to see whether a common pattern recognition receptor called the Inceptin Receptor (INR) had changed over millions of years, gaining or losing the ability to recognise caterpillars.

They found that a single, 28-million-year-old receptor gene perfectly corresponds with the plant immune response to the caterpillar peptides. They also found that among the descendants of the oldest plant ancestors that first evolved the receptor gene, a few species that could not respond to the caterpillar peptides had lost the gene.

To understand how this ancient gene acquired the ability to recognise new peptides from today’s pathogens, the team employed a technique called ancestral sequence reconstruction where they combined information from all modern-day receptor genes to predict the 28-million-year-old original sequence. This ancestral receptor was able to respond to caterpillar peptides. However, a slightly older version with 16 changes in the receptor sequence could not.

This genetic history, together with computer models showing how the ancient and current receptor structures may have differed, provide clues to how the receptor evolved. It suggests that there was a key insertion of a new gene into the ancestral plant’s genome more than 32 million years ago, followed by rapid evolution of diverse forms of the new receptor. One of these forms acquired the ability to respond to caterpillar peptides, and this new capability is now shared in dozens of descendant legume species.

“We have identified the emergence and secondary loss of a key immunity trait over plant evolution,” concludes senior author Adam Steinbrenner, Assistant Professor at the Department of Biology, University of Washington. “In the future, we hope to learn more about genome-level processes that generate new receptor diversity and identify as-yet unknown immune receptors within plant groups. As increasing genomic data becomes available, such approaches will identify ‘missing’ receptors that are useful traits to reintroduce into plants to help protect crops.”


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Materials provided by eLifeNote: Content may be edited for style and length.


Journal Reference:

  1. Simon Snoeck, Bradley W Abramson, Anthony G K Garcia, Ashley N Egan, Todd P Michael, Adam Steinbrenner. Evolutionary gain and loss of a plant pattern-recognition receptor for HAMP recognitioneLife, 2022; 11 DOI: 10.7554/eLife.81050

Cite This Page:

eLife. “A gene from 28 million years ago protects today’s plants against caterpillars.” ScienceDaily. ScienceDaily, 15 November 2022. <www.sciencedaily.com/releases/2022/11/221115113928.htm>.

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NOVEMBER 16, 2022

Functions of transcription factors in maize resistance to insects and jasmonate signaling revealed

by Zhang Nannan, Chinese Academy of Sciences

corn
Credit: CC0 Public Domain

Maize (Zea mays) is an important food, feed, and bioenergy crop that plays a pivotal strategic role in food security, while insect pests seriously affect the yield and quality of maize. Benzoxazinoids (BXDs) and volatile terpenes are insect-resistant defensive compounds in maize. BXDs are toxic to insects and they directly inhibit insect growth and development, and volatile terpenes attract the natural enemies of herbivorous insects.

Previous studies have shown that jasmonic acid (JA) treatment can promote the accumulation of BXDs and volatile terpenes in maize, but the underlying molecular mechanisms were unknown.

A research team led by Prof. Wu Jianqiang at the Kunming Institute of Botany of the Chinese Academy of Sciences (KIB/CAS) has elucidated the functions of maize MYC2s in JA-mediated insect defense response by means of genetics, biochemistry, molecular biology, and bioinformatics.

According to the researchers, compared with the wild-type maize plants, the maize mutants, in which MYC2s were knocked out, were highly susceptible to the insects Mythimna separata and Spodoptera frugiperda.

The maize MYC2s mutants also showed a feminized tassel phenotype. Thus, MYC2s regulate maize insect resistance and sex determination of tassels. The researchers further demonstrated that maize MYC2s positively regulate the biosynthesis of BXDs and volatile terpenes, and the RNA-Seq and CUT&Tag-Seq analyses also revealed the regulatory landscape of maize MYC2s.

Moreover, they identified seven transcription factors that are physically targeted by MYC2s and they are likely involved in regulating the biosynthesis of BXDs.

This study provides important new insight into the molecular mechanisms of insect resistance and JA signaling in maize.

This work was published in the Journal of Integrative Plant Biology entitled “ZmMYC2s play important roles in maize responses to simulated herbivory and jasmonate.”

More information: Canrong Ma et al, ZmMYC2s play important roles in maize responses to simulated herbivory and jasmonate, Journal of Integrative Plant Biology (2022). DOI: 10.1111/jipb.13404

Provided by Chinese Academy of Sciences 

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Bonwell: the multi-fruited mini cucumber with high resistance to CGMMV

In ‘The future is sky’ series, we show that shared entrepreneurship is of paramount importance. Blake Fischer, Head Grower at JEM Farms, discusses the partnership between JEM Farms and Rijk Zwaan in this second video. “It’s always great to have another set of eyes looking at your crop and pointing things out that we can all learn from”, says Blake Fischer.

Furthermore, JEM Farms shared their experiences with our high CGMMV resistant mini-cucumber variety, Bonwell. Curious to learn more about ‘The future is sky’ series or Bonwell?

Publication date: Mon 14 Nov 2022

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The missing link: Fatty acid metabolism impacts plant immunity

Peer-Reviewed Publication

AMERICAN PHYTOPATHOLOGICAL SOCIETY

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Dr. Ye Xia and Zhenzhen Zhao
IMAGE: TWO OF THE STUDY’S AUTHORS, DR. YE XIA (RIGHT) AND ZHENZHEN ZHAO view more CREDIT: DR. YE XIA

That healthy salad you ate for lunch contains fatty acids—surprised? Fatty acids, lipids, and fats in our food may sound undesirable, but they are foundational to human life and to the plants we consume. Their interaction with certain proteins helps regulate plant growth.

Plant fatty acids (FAs) serve as structural constituents of cell membranes and are building blocks for certain hormones, among other things. Fatty acids are stabilized during synthesis by acyl carrier proteins (ACPs), found throughout all branches of life, which support and elongate the growing FA chains. A recent study, by Zhenzhen Zhao (of The Ohio State University) and colleagues, reveals a new dimension to the role of FA biosynthesis in plants by providing a direct link to the plant defense mechanism.

Published in Molecular Plant-Microbe Interactions (MPMI), the study found that the Arabidopsis plants lacking the Acyl Carrier Protein 1 (ACP1) were more resistant to the bacterial pathogen, Pseudomonas syringae, indicating that FA metabolism plays a critical role in plant immunity. Corresponding author Ye Xia comments, “Our research provided a direct link between FA metabolism and plant immunity and unraveled the potential role of ACP1 in plant defense across economically important crops.”

The study shows that ACP1 is essential to maintaining the homeostasis of hormones that affect a variety of plant stress responses. This effect on hormone signaling creates a broad arena for ACP1 to influence other biotic and abiotic stresses, an area ripe for further exploration. In addition, this research emphasizes the importance of studying individual members of gene families that may have discrete functions, since ACP1 plays a role in plant resistance—distinct from that of its close family member, ACP4.

ACP1 homologs are currently present in a variety of economically important crops. In the future, genetically engineering these important crops to modulate the expression of ACP1 is an exciting avenue to create disease-resistant varieties that withstand bacterial and other pathogen infections.

For additional details, read Involvement of Arabidopsis Acyl Carrier Protein 1 in PAMP-Triggered Immunity in Vol. 35, No. 8 / August 2022 of MPMI.

Follow two of the authors on Twitter

Zhenzhen Zhao: @­_ZhenzhenZhao

Ye Xia: @xiaye9999

About Molecular Plant-Microbe Interactions (MPMI)

Molecular Plant-Microbe Interactions® (MPMI) is a gold open access journal that publishes fundamental and advanced applied research on the genetics, genomics, molecular biology, biochemistry, and biophysics of pathological, symbiotic, and associative interactions of microbes, insects, nematodes, or parasitic plants with plants.

Follow us on Twitter @MPMIjournal and visit https://apsjournals.apsnet.org/journal/mpmi to learn more.


JOURNAL

Molecular Plant-Microbe Interactions

DOI

10.1094/MPMI-02-22-0049-R 

ARTICLE TITLE

Involvement of Arabidopsis Acyl Carrier Protein 1 in PAMP-Triggered Immunity

ARTICLE PUBLICATION DATE

31-Aug-2022

COI STATEMENT

The author(s) declare no conflict of interest.

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Alliance for Science

Disease-resistant GM cassava promises to be game-changer for Kenya

BY JOSEPH MAINA

AUGUST 15, 2022

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At the Kenya Agricultural and Livestock Research Organization (KALRO) center in Mtwapa, Kenya, scientist Paul Kuria uproots two sets of cassava tubers exposed to the devastating cassava brown streak disease (CBSD).

One of the plants is a conventional cassava variety that has no immunity to the disease. The second has been genetically modified (GM) to resist the disease. Kuria punctiliously slices each of the tubers open, and the difference between the two is stark — like night and day.

The conventional tuber looks emaciated and is punctured with brownish, unsavory spots dotting the entire circumference of its flesh. The GM tuber, on the other hand, is the picture of good health. Its skin is flawless and firm, and its flesh has an impeccable, white lustre.

CBSD is considered one of the world’s most dangerous plant diseases due to its significant impact on food and economic security. Cassava varieties that are resistant to the disease could considerably improve the crop’s ability to feed Africa while generating income for smallholder farmers.

In severe cases, the disease can lead to 100 percent yield loss. As noted by KALRO and its partners, cassava resistant to CBSD is in high demand by farmers where the crop is grown.

Meeting that demand has been an elusive target for plant breeders. But through modern biotechnology, a collaborative effort known as the VIRCA project has developed CBSD-resistant cassava line 4046. It has the potential to prevent 90 percent of crop damage, thus improving the yield and marketability of cassava roots.

“We used genetic engineering and produced an improved cassava,” Professor Douglas Miano, the lead scientist in the project, told journalists and farmers who toured the KALRO grounds in Mtwapa in early August.

“It’s the first GM cassava in the world, and Kenya is leading in this production,” Miano said.

The VIRCA (Virus Resistant Cassava for Africa) project was conceived in 2005 with the aim of solving the viral diseases that suppress cassava yields and reduce farmer incomes in East Africa. It brings together KALRO, the National Agricultural Research Organization (NARO) of Uganda and the Donald Danforth Plant Science Centre (DDPSC) in the United States.

“We have two main diseases affecting cassava production — CBSD and cassava mosaic disease,” Miano explained. “Cassava mosaic disease affects the leaves of the crop. The net effect is a reduction in the amount of cassava that is produced. CBSD, on the other hand, destroys the roots and affects the tuber.”

Scientists Paul Kuria displays GM disease-resistant cassava (left) vs cassava infected with CBSD. Photo: Joseph Maina

Dr. Catherine Taracha, a Kenyan who is on the project’s leadership team, said that plant viruses create a huge challenge for farmers.

“Cassava productivity is significantly hampered by viral diseases, and so we sought to develop a cassava line that would resist the viruses and thereby improve farmers’ livelihoods by boosting productivity and earnings from the crop,” Taracha said.

Because the line is yet to be approved for commercial release, the work is being carried out in regulated confined field trial conditions. If and when Kenya’s National Biosafety Authority approves line 4046 for the market, the new CBSD-resistant varieties would undergo normal government variety assessment and registration by regulators before being distributed to farmers.

The scientists further assure that CBSD-resistant cassava varieties are no different than their conventional equivalents — aside from their ability to resist CBSD.

“Due to the ability to resist CBSD, these varieties will be more productive with better quantity and quality of root yields,” Miano said.. “This will translate to greater demand and more profits for farmers.”

In addition, CBSD-resistant cassava line 4046 will produce disease-free planting material and thereby contribute to long-term sustainability of the cassava crop.

There will be no technology fee associated with line 4046, scientists say, implying that cassava stakes and cuttings will cost about the same as other highly valued cassava varieties.

Cuttings from CBSD-resistant cassava can be replanted in the same way farmers replant conventional cassava. They can also be grown with other crops because cultivation practices are the same as for conventional varieties.

The developers have further assured that CBSD-resistant cassava line is safe for the environment and biodiversity.

“We have developed the GM cassava up to the point where we have conducted all the safety studies and demonstrated that it is safe as food, feed and to the environment,” Miano said.

The general public and key stakeholders have been involved in the project, and it is anticipated that farmers and communities will be involved in selecting the best CBSD-resistant cassava varieties for their needs.

Cassava roots and leaves are the nutritionally valuable parts of the plant. The tuber is rich in gluten-free carbohydrates while the leaves provide vitamins A and C, minerals and protein. In addition to its nourishing properties, stakeholders have also identified cassava’s potential to spur Kenya’s industrial growth.

“Cassava is an important food crop, but we can also use it to industrialize in Kenya,” Miano asserted. “However, we have not yet been able to achieve this as a country.”

Miano identified starch as a potential cassava product that the country can leverage to advance its industrial growth. It is also projected that the improved cassava can protect farmers from devastating losses of this important food crop and contribute to the creation of thousands of jobs along the value chain due to the crop’s use as animal feed.

The scientists note that modern biotechnology is by far the best option to incorporate CBSD resistance in cassava cultivars carrying farmer-preferred characteristics. Similar approaches have been used to confer resistance to plant viruses and have been authorized by regulatory bodies around the world, including virus-resistant pawpaw, squash and beans.

Image: Scientist Paul Kuria displays cassava infected with cassava brown streak disease (left) and a GM variety that resists the devastating disease. Photo: Joseph Maina


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Researchers identify genes potentially responsible for sugarcane’s resistance to pests, cold and drought

by Ricardo Muniz, FAPESP

Researchers identify genes potentially responsible for sugarcane's resistance to pests, cold and drought
Researchers identify genes potentially responsible for sugarcane’s resistance to pests, cold and drought. Credit: Luciana Rossini/IAC, Sugarcane Center, Ribeirão Preto

A study conducted at the State University of Campinas (UNICAMP) in Brazil has identified orphan genes in wild sugarcane (Saccharum spontaneum), a species with exceptional resistance to biotic stresses such as nematodes, fungi, bacteria and other pests and diseases, and abiotic stresses such as cold, drought, salinity and nutritionally deficient soil.

According to an article on the study published in the journal Frontiers in Plant Science, the scientists responsible had set out to see if the orphan genes in S. spontaneum played a significant role in its stress resistance properties.

All living beings have genes that closely resemble those of other organisms’ genomes. Plants, for example, share the genes involved in photosynthesis. On the other hand, most organisms also have orphan or lineage-specific genes.

Orphan genes are found in a particular taxonomic group with no significant sequence similarity to genes from other lineages. They are sometimes called taxonomically restricted genes for this reason.

Birds, for example, have some genes that differ a great deal from those of mammals. Recent research has shown that even organisms in closely related species belonging to the same genus can have genes not shared by other species.

The researchers were interested in S. spontaneum because of characteristics such as past whole-genome duplication events that resulted in several copies of the same gene. Scientific evidence suggests orphan genes can originate in copies of pre-existing genes whose sequences change over time owing to mutations and eventually differ entirely from the original sequences.

Another possible explanation for the origin of orphan genes could be reorganization of genomic regions that do not encode genes, frequently seen in organisms with complex genomes, such as sugarcane.

“In the study, we identified parts of the genome of S. spontaneum that have no similarities to genes in any other organism. We believe they may be responsible for physiological traits or properties peculiar to the species,” said Cláudio Benício Cardoso-Silva, first author of the article. He conducted the project as postdoctoral research at UNICAMP’s Center for Molecular Biology and Genetic Engineering (CBMEG).

“As these plants evolved, some genes were expressed to a greater or lesser extent in response to various types of abiotic stress, particularly cold. This may mean they’re regulated as a result of these stresses,” said Cardoso-Silva, whose postdoctoral research was supervised by Anete Pereira de Souza, professor of plant genetics at UNICAMP’s Institute of Biology and last author of the article.

The researchers do not believe they can categorically conclude that the orphan genes they identified make the plant more stress-tolerant based on the results of the study. “But the fact that they’re regulated under conditions of stress serves as an alert to the possibility that they may play an important role in these processes,” he said.

The next step will be to experiment on plants submitted to various kinds of stress in order to investigate how orphan genes behave in terms of expression, compared to non-stressed plants. Once the best candidate genes are confirmed, biotech applications involving their insertion into commercially valuable plants can be studied, leading in future to the possibility of developing sugarcane varieties more resistant to environmental pressures.

“We shone a spotlight on this possibility for anyone who wants to use the data in the article to continue the research, or for scientists who work with gene transformation and editing, which is a different research field, to choose one or two genes as candidates and do the validation,” said Cardoso-Silva, who continues to work with genomics at the State University of Northern Rio de Janeiro (UENF). “My current research focuses on the evolutionary aspect of gene family expansion,” he explained.

“Today we have CRISPR [the gene editing technique], which offers biotech professionals a chance to select genes for tolerance of drought, salinity, cold or heat at a time when crop resilience with fewer inputs is paramount,” Souza said.


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A New Green Revolution Is in the Offing

Thanks to some amazing recent crop biotech breakthroughs

RONALD BAILEY | 8.10.2022 5:00 PM

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man stands in wheat field facing away from camera with outstretched arms

(Noam Armonn | Dreamstime.com)

A recent spate of crop biotech breakthroughs presage a New Green Revolution that will boost crop production, shrink agriculture’s environmental footprint, help us weather future climate change, and provide better nutrition for the world’s growing population.

The first Green Revolution was generated through the crop breeding successes pioneered by agronomist Norman Borlaug back in the 1960s. The high-yielding dwarf wheat varieties bred by Borlaug and his team more than doubled grain yields. The Green Revolution averted the global famines confidently predicted for the 1970s by population doomsters like Stanford entomologist Paul Ehrlich. Other crop breeders using Borlaug’s insights boosted yields for other staple grains. Since 1961, global cereal production has increased 400 percent while the world population grew by 260 percent. Borlaug was awarded the Nobel Peace Prize in 1970 for his accomplishments. Of course, the disruptions of the COVID-19 pandemic and Russia’s invasion of Ukraine are currently roiling grain and fertilizer supplies.

Borlaug needed 20 years of painstaking crossbreeding to develop his high-yield and disease-resistant wheat varieties. Today, crop breeders are taking advantage of the tools of modern biotechnology that can dramatically increase the rate at which yields increase and drought- and disease-resistance can be imbued in crops.

The Green Revolution’s crops required increased fertilizer applications to achieve their higher yields. However, fertilizers have some ecologically deleterious side effects. For example, the surface runoff of nitrogen and other fertilizers not absorbed by crops spurs the growth of harmful alga in rivers, lakes, and coastal areas. In addition, excess nitrogen fertilizer gets broken down by soil bacteria such that there are rising atmospheric concentrations of the greenhouse gas nitrous oxide, which, pound for pound, has 300 times the global warming potential of carbon dioxide.

The good news is that in the last month, two teams of modern plant breeders have made breakthroughs that will dramatically cut the amount of nitrogen fertilizers crops need for grain production. In July, Chinese researchers reported the development of “supercharged” rice and wheat crops, which they achieved by doubling the expression of a regulatory gene that increases nitrogen uptake by four- to fivefold and enhances photosynthesis. In field trials, the yields of the modified rice were 40 to 70 percent higher than those of the conventional varieties. One upshot is that farmers can grow more food on less land using fewer costly inputs.

Some crops like soybeans and alfalfa get most of the nitrogen fertilizer they need through their symbiotic relationship with nitrogen-fixing soil bacteria. Soybeans supply the bacteria living on their roots with sugars, and the bacteria in turn take nitrogen from the air and turn it into nitrate and ammonia fertilizers for the plants. However, nitrogen-fixing bacteria do not colonize the roots of cereal crops.

A team of researchers associated with the University of California Davis reported in July their success in gene editing rice varieties to make their roots hospitable to nitrogen-fixing bacteria. As a result, when grown under conditions of limited soil nitrogen, the yields of the gene-edited varieties were 20 to 35 percent higher than those of the conventional varieties. The researchers believe their gene-editing techniques can be applied to other cereal crops.

This new biotech-enabled Green Revolution promises a future in which more food from higher yields grown using less fertilizer means more farmland restored to nature, less water pollution, and reduced greenhouse gas emissions.

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Preventing late blight with GMO potatoes could ease food insecurity

Photos courtesy of MSUGMO late blight resistant potato plants

BLIGHT RESISTANCE: Researchers have developed GMO late blight-resistant plants, pictured here alongside conventional plants.

Commentary: Stop GMO critics from making choices for farmers in Africa or Asia.

Dave Douches | Aug 10, 2022

fps-generic.jpg

For many decades, my research has focused on genetically improving potatoes. Many think of potatoes as a less-than-ideal nutrition choice. The potato itself is a nutritional powerhouse, but it’s how we choose to prepare and eat them that often overshadows their nutritive benefits.

Nutritionally, potatoes produce a large amount of energy-rich carbohydrates and are high in vitamin C and potassium. Through crossbreeding, I have also developed a deep, purple-fleshed potato that is high in antioxidants typically found in fruits.

As the third-most important human food in the world, potatoes can play a critical role in global food security. Over the past few decades, world potato production growth has primarily been in developing countries. As the highest-yielding staple crop per acre, potatoes provide countless savings in land use across the globe.

Despite increased potato production and high-yield potential, yields in developing countries have not reached their full potential. Smallholder farmers often lack access to quality seed and knowledge of effective disease management practices.

One of the most important potato diseases because of its effect on crop yield is late blight (the disease that caused the Irish potato famine in 19th century). Late blight disease is recognized as one of the most destructive diseases of potatoes and is a major constraint of profitable potato production worldwide. Late blight management costs and losses from yield reductions are estimated at more than $6 billion per year globally.

The best way to overcome the problem of late blight is to produce a potato with durable resistance to the disease. An innovative solution to the grand challenge does exist, but the solution does not enjoy a consensus of support around the globe.

Late blight disease resistance can be achieved in potatoes through the introduction of three strong disease resistance genes from a wild species of potato into varieties preferred by consumers and farmers. These resistant varieties cannot be obtained by conventional crossbreeding. 

Genetically modified organisms

The late blight resistant potato I refer to was developed using genetic engineering, a scientific process that can insert and express genes (DNA) to improve an organism. This technology has been celebrated or villainized, depending on whom you trust.

As a plant breeder, I believe GE expands the toolbox that a breeder can use to solve challenges, especially in vegetative crops such as potatoes, where specific varieties are preferred in the market.

In medicine, one of the most recognizable examples is in the production of human insulin, which is manufactured using recombinant DNA technology. It has been licensed for human use since 1982 and widely prescribed to treat diabetes. GE has been widely accepted by the public in medical applications.

potatoes growing in field

YIELD ROBBER: Late blight disease is recognized as one of the most destructive diseases of potatoes and is a major constraint of profitable potato production worldwide. Researchers say the best way to overcome the problem of late blight is to produce a potato with durable resistance to the disease. Pictured is the difference in yield between LBR potato plants and conventional potatoes.

In agriculture, despite over 25 years of successful commercial production of many staple crops, GE crops still endure stiff criticism. The anti-GMO movement is well-funded and well-organized. Three claims of anti-GMO advocates are that GE is harmful to human and environmental health; that GMOs are unnatural; and were developed by large multinational corporations looking to control the seed sector and farmers.

These beliefs persist even after overwhelming scientific evidence continues to prove that current GMOs are safe to eat, and that disease- and insect-resistant GMOs can be good for the environment and health of farmers, and in many cases reduce input costs.

Risk or benefit?

A recent review offers a risk-benefit analysis of GMOs. The authors note that scientific evidence shows the technology is not only safe, but can also provide economic, environmental and health benefits. In addition, legal frameworks that regulate GMO crops exist to ensure safe products for people, animals and the environment.

As director of the Feed the Future Global Biotech Potato Partnership supported by the U.S. Agency for International Development (USAID), I have seen firsthand the benefits of the GE technology. The partnership is working to develop late blight resistant potato varieties in developing countries. Our late blight disease-resistant potatoes have demonstrated complete protection against the disease.

We have held field trials in Indonesia, where late blight disease is so prevalent, it can strike soon after plant emergence and destroy an entire potato field within weeks. On average, Indonesian farmers spray up to 17 times during a 90-day cropping cycle. That equates to two to three times a week where farmers are exposed to fungicides sprays, and oftentimes they apply without proper protective clothing.  

Science and regulatory agencies around the globe have consistently found crops and food developed by GE to be safe. In fact, 159 Nobel laureates to date have signed an open letter to the leaders of Greenpeace (an outspoken opponent of the technology), the United Nations and governments around the world in support of biotechnology, noting, “There has never been a single confirmed case of a negative health outcome for humans or animals from their consumption. Their environmental impacts have been shown repeatedly to be less damaging to the environment, and a boon to global biodiversity.”

The opportunity of choice

Wherever you may land in the GMO trust conversation, the technology is growing and expanding. In 2019, 190.4 million hectares of biotech crops were grown in 29 countries. The U.S. leads the world with 71.5 million hectares, with an average 95% crop adoption rate for GE soybeans, maize and canola. According to the USDA, more than 90% of U.S. corn, upland cotton and soybeans are GE varieties.  

In the U.S., which many consider a privileged society, people have many options and choices when it comes to making their food decisions. We are fortunate to have the opportunity of choice. Many developing countries struggle to achieve food security and cannot produce enough nutritious food to feed their people.

The State of Food Security and Nutrition in the World 2021 report by the U.N.’s Food and Agriculture Organization notes that 149.2 million, or 22%, of children younger than age 5 were affected by stunting, and 45.4 million children were affected by wasting (low weight for height).

More than nine out of 10 of all children affected by stunting or wasting are in Africa and Asia. The study also reports undernourished people in Africa (418 million) and Asia (282 million) rose by 103 million people from 2019 to 2020.

We cannot just ask farmers to grow more of what they’ve been growing to solve global food security. Farmers need to have a choice to grow more strategic crops and varieties that achieve higher and more stable yields resilient to climate shocks and threats.

This choice is even more critical in developing countries such as Bangladesh where we are working to bring the late blight disease resistant potato to smallholder farmers. Genetic engineering can offer disease- and pest-resistant and climate-tolerant crop plants for the farmers. GE crops can also lead to improved and enhanced nutritional traits in food products for the consumers.

In industrialized countries such as the U.S. and Europe, agricultural productivity can be easily increased through new technologies and innovations at every point within the food-value chain. We are afforded the luxury of opportunity.

However, for the smallholders in a country like Bangladesh, farming can be an entirely manual process, from plowing to planting and weeding, to harvest by hand. Technology and innovation are often out of reach for these farmers.

Bangladesh potato farmers at harvest

HARVEST: Bangladesh potato farmers work at harvest.

Many of those from the developed world can choose to select which organic, GE or conventionally bred food products to buy at a nearby store full of options. Billions of others are not afforded this choice. However, many GMO critics are making the choice for a farmer in Africa or Asia on which crops to grow and feed their communities by fighting against their use.

These opinions of distrust of the technology are often loud, misleading of the science, and influence leaders of developing countries to ban their farmers access to the technology. I believe every country and every farmer should have the right to make safe choices on their food security without the influence of disinformation and dissatisfaction of others.

We need to trust data, science and facts to solve global grand challenges. Sharpening our media literacy and critical-thinking skills will enable us to avoid disinformation, eliminate participation in misinformation sharing, and become advocates of truth.

Douches is a professor and director of the Potato Breeding and Genetics Program, and director of the Plant Breeding, Genetics and Biotechnology Graduate Program in the Department of Plant, Soil and Microbial Sciences in the College of Agriculture and Natural Resources at Michigan State University. He is also the project director of the Feed the Future Global Biotech Potato Partnership.

TAGS: CROPS

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prof. tzin

News Briefs

Prof. Vered Tzin, the plant biologist who is figuring out how wild wheat protects itself from insects. Courtesy

An Israeli plant biologist has discovered a way to protect cultivated wheat from insects without pesticides.

Prof. Vered Tzin of the Ben Gurion University of the Negev has discovered two defense mechanisms of wild wheat against pests that she hopes to reproduce in cultivated wheat.

Wild wheat has a coating of “hairs” that prevent insects from burrowing into their stalks. It also produces a poison – benzoxazinoids (BXDs) – that discourages bugs from eating it.

Cultivated wheat has lost many of its protective mechanisms, which allows insects to destroy a lot of the yield. Luckily, they can be bred back into cultivated wheat and improve pest resistance without relying on pesticides that do not work that well. 

PhD student Zhaniya Batyrshina is the first to have isolated the gene that controls the production of this poison.

“Wheat is an essential staple for so many and we must do all we can to safeguard this critical crop from loss by insects and disease,” says Prof. Tzin.

One of the most serious threats to it are aphids, tiny insects which suck out the its nutrients and also introduce deadly plant disease. There are about 5,000 different species of aphids all over the world.

They cause significant losses in yield, and the gradual increase in global temperatures has increased their reproduction rate. 

“Now that we know which gene controls its production, we can generate improved cultivated wheat with the same self defense capabilities,” says Prof. Tzin.

Prof. Tzin studied the wild emmer wheat which has long been found in the Fertile Crescent and is an ‘ancestor’ of both durum (pasta) and bread wheat.

Wheat provides 20 per cent of the world population’s caloric and human protein intake, and is essential for both human and livestock diets, which makes these findings significant.

The findings were published in the Journal of Experimental Botany and Frontiers in Plant Science.

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Breeder develops disease-resistant snack cucumbers varieties

“Developing varieties with resistances takes time but it’s an important role we play as plant breeders”

Rijk Zwaan is taking innovation to new heights in snack cucumbers by focusing on high wire varieties with the combination of Powdery Mildew (PM) and Cucumber Green Mottled Mosaic Virus (CGMMV) resistance. This is the latest development in the company’s ever-growing range of flavorsome snack cucumbers in various sizes and colors, all with the best possible resistances to help growers harvest a healthy crop.

Snack varieties with resistances to CGMMV and Powdery Mildew (PM)
Since introducing Quarto RZ – one of the first varieties of snack cucumber – in 2005, Rijk Zwaan has worked with growers and listened to consumers to breed new varieties that are not only agronomically sound and productive, but also delicious and visually appealing. “Developing varieties with resistances takes time but it’s an important role we play as plant breeders,” says Marcel van Koppen, a Dutch-based crop specialist at Rijk Zwaan. “Growers face pressure from a number of diseases such as mildew as well as viruses that can have serious consequences for crop viability. In 2019, we enhanced the snack cucumber range with the introduction of Quayal RZ as a PM-resistant version of Qwerty RZ. We’ve now taken our range to the next level once again by asking our breeders to develop snack cucumber varieties with a combination of PM and CGMMV resistances. This will be a significant improvement for growers and other value chain partners.”

Innovating the snack cucumber category for consumers
It is important to keep the segment fresh and exciting, since more than 35% of consumers in some markets eat snack cucumbers. One of Rijk Zwaan’s new varieties is Quirk RZ, a unique bi-coloured ‘baby apple’ snack cucumber with a sweet taste and good shelf life. Additionally the company has made further improvements in the smaller cucumber segment, resulting in the development of one-bites as well as a white-skinned variety which looks very striking in snack cucumber medleys. 

The future is sky
Rijk Zwaan continuously conducts research into new cucumber varieties, important resistances and technical characteristics. From generation to generation, the company maintains an ongoing dialogue with growers to anticipate new challenges in changing cultivation conditions, such as high wire. That’s why most of the company’s current varieties are suitable for both umbrella and high wire systems. “The future is the sky,” they say.

For more information:
Rijk Zwaan
info@rijkzwaan.com
www.rijkzwaan.com      

Publication date: Wed 10 Aug 2022

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