Global Plant Council Blog

Plant Science for Global Challenges

Tag: sustainable agriculture (page 2 of 9)

Taking the brakes off plant production: not so good after all

Reposted with kind permission from the MSU-DOE Plant Research Laboratory. Original article.

By: Igor Houwat, Atsuko Kanazawa, David Kramer

The need for speed: increasing plant yield is one way to increase food and fuel resources. But asking plants to simply do more of the usual is a strategy that can backfire. Photo by Romain Peli on Unsplash

When engineers want to speed something up, they look for the “pinch points”, the slowest steps in a system, and make them faster.

Say, you want more water to flow through your plumbing. You’d find the narrowest pipe and replace it with a bigger one.

Many labs are attempting this method with  photosynthesis, the process that plants and algae use to capture solar energy.

All of our food and most of our fuels have come from photosynthesis. As our population increases, we need more food and fuel, requiring that we improve the efficiency of photosynthesis.

But, Dr. Atsuko Kanazawa and the Kramer Lab are finding that, for biological systems, the “pinch point” method can potentially do more harm than good, because the pinch points are there for a reason!  So, how can this be done?

 

ATP synthase: an amazing biological nanomachine

Atsuko and her colleagues at the MSU-DOE Plant Research Laboratory (PRL) have been working on this problem for over 15 years. They have focused on a tiny machine in the  chloroplast called the  ATP synthase, a complex of proteins essential to storing solar energy in “high energy molecules” that power life on Earth.

That same ATP molecule and a very similar ATP synthase are both used by animals, including humans, to grow, maintain health, and move.

In plants, the ATP synthase happens to be one of the slowest process in photosynthesis, often limiting the amount of energy plants can store.

Photosynthetic systems trap sunlight energy that starts the reaction to move electrons forward in an assembly-line fashion to make useful energy compounds. The ATP synthase is one of the “pinch points” that slows the flow as needed, so plants stay healthy. In cfq, the absence of feedback leads to an electron pile up at PSI, and a crashed system. By MSU-DOE Plant Research Laboratory, except tornado graphic/CC0 Creative Commons

 

Kicking up the gears of plant production

Atsuko thought, if the ATP synthase is such an important pinch point, what happens if it were faster? Would it be better at photosynthesis and give us faster growing plants?

Years ago, she got her hands on a mutant plant, called cfq, from a colleague. “It had an ATP synthase that worked non-stop, without slowing down, which was a curious example to investigate. In fact, under controlled laboratory conditions – very mild and steady light, temperature, and water conditions – this mutant plant grew bigger than its wild cousin.”

But when the researchers grew the plant under the more varied conditions it experiences in real life, it suffered serious damage, nearly dying.

“In nature, light and temperature quality change all the time, whether through the passing hours, or the presence of cloud cover or winds that blow through the leaves,” she says.

 

Plants slow photosynthesis for a reason!

Recent innovations from the Kramer lab are enabling Atusko and her colleagues to probe into how real environmental conditions affect plant growth.

Atsuko’s research now shows that the slowness of the ATP synthase is not an accident; it’s an important braking mechanism that prevents photosynthesis from producing harmful chemicals, called reactive oxygen species, which can damage or kill the plant.

“It turns out that sunlight can be damaging to plants,” says Dave Kramer, Hannah Distinguished Professor and lead investigator in the Kramer lab.

“When plants cannot use the light energy they are capturing, photosynthesis backs up and toxic chemicals accumulate, potentially destroying parts of the photosynthetic system. It is especially dangerous when light and other conditions, like temperature, change rapidly.”

“We need to figure out how the plant presses on the brakes and tune it so that it responds faster…”

The ATP synthase senses these changes and slows down light capture to prevent damage. In that light, the cfqmutant’s fast ATP is a bad idea for the plant’s well-being.

“It’s as if I promised to make your car run faster by removing the brakes. In fact, it would work, but only for a short while. Then things go very wrong!” Dave says.

“In order to improve photosynthesis, what we need is not to remove the brakes completely, like in cfq, but to control them better,” Dave says. “Specifically, we need to figure out how the plant presses on the brakes and tune it so that it responds faster and more efficiently,” David says.

Atsuko adds: “Scientists are trying different methods to improve photosynthesis. Ultimately, we all want to tackle some long-term problems. Crucially, we need to continue feeding the Earth’s population, which is exploding in size.”

The study is published in the journal, Frontiers in Plant Science.

 

Fighting Fusarium wilt to beat the bananapocalypse

Dr. Sarah Schmidt (@BananarootsBlog), Researcher and Science Communicator at The Sainsbury Laboratory Science. Sarah got hooked on both banana research and science writing when she joined a banana Fusarium wilt field trip in Indonesia as a Fusarium expert. She began blogging at https://bananaroots.wordpress.com and just filmed her first science video. She speaks at public events like the Pint of Science and Norwich Science Festival.

 

Every morning I slice a banana onto my breakfast cereal.

And I am not alone.

Every person in the UK eats, on average, 100 bananas per year.

Bananas are rich in fiber, vitamins, and minerals like potassium and magnesium. Their high carbohydrate and potassium content makes them a favorite snack for professional sports players; the sugar provides energy and the potassium protects the players from muscle fatigue. Every year, around 5000 kg of bananas are consumed by tennis players at Wimbledon.

But bananas are not only delicious snacks and handy energy kicks. For around 100 million people in Sub-Saharan Africa, bananas are staple crops vital for food security. Staple crops are those foods that constitute the dominant portion of a standard diet and supply the major daily calorie intake. In the UK, the staple crop is wheat. We eat wheat-based products for breakfast (toast, cereals), lunch (sandwich), and dinner (pasta, pizza, beer).

In Uganda, bananas are staple crops. Every Ugandan eats 240 kg bananas per year. That is around 7–8 bananas per day. Ugandans do not only eat the sweet dessert banana that we know; in the East African countries such as Kenya, Burundi, Rwanda, and Uganda, the East African Highland banana, called Matooke, is the preferred banana for cooking. Highland bananas are large and starchy, and are harvested green. They can be cooked, fried, boiled, or even brewed into beer, so have very similar uses wheat in the UK.

In West Africa and many Middle and South American countries, another cooking banana, the plantain, is cooked and fried as a staple crop.

In terms of production, the sweet dessert banana we buy in supermarkets is still the most popular. This banana variety is called Cavendish and makes up 47% of the world’s banana production, followed by Highland bananas (24%) and plantains (17%). Last year, I visited Uganda and I managed to combine the top three banana cultivars in one dish: cooked and mashed Matooke, a fried plantain and a local sweet dessert banana!

 

Three types of banana in a single dish in Uganda.

Another important banana cultivar is the sweet dessert banana cultivar Gros Michel, which constitutes 12% of the global production. Gros Michel used to be the most popular banana cultivar worldwide until an epidemic of Fusarium wilt disease devastated the banana export plantations in the so-called “banana republics” in Middle America (Panama, Honduras, Guatemala, Costa Rica) in the 1950s.

Fusarium wilt disease is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC). The fungus infects the roots of the banana plants and grows up through the water-conducting, vascular system of the plant. Eventually, this blocks the water transport of the plant and the banana plants start wilting before they can set fruits.

Fusarium Wilt symptoms

Fusarium Wilt symptoms

The Fusarium wilt epidemic in Middle America marked the rise of the Cavendish, the only cultivar that could be grown on soils infested with FOC. The fact that they are also the highest yielding banana cultivar quickly made Cavendish the most popular banana variety, both for export and for local consumption.

Currently, Fusarium wilt is once again the biggest threat to worldwide banana production. In the 1990s, a new race of Fusarium wilt – called Tropical Race 4 (TR4) – occurred in Cavendish plantations in Indonesia and Malaysia. Since then, TR4 has spread to the neighboring countries (Taiwan, the Philippines, China, and Australia), but also to distant locations such as Pakistan, Oman, Jordan, and Mozambique.

Current presence of Fusarium wilt Tropical Race 4. Affected countries are colored in red.

In Mozambique, the losses incurred by TR4 amounted to USD 7.5 million within just two years. Other countries suffer even more; TR4 causes annual economic losses of around USD 14 million in Malaysia, USD 121 million in Indonesia, and in Taiwan the annual losses amount to a whopping USD 253 million.

TR4 is not only diminishing harvests. It also raises the price of production, because producers have to implement expensive preventative measures and treatments of affected plantations. These preventive measures and treatments are part of the discussion at The World Banana Forum (WBF). The WBF is a permanent platform for all stakeholders of the banana supply chain, and is housed by the United Nation’s Food and Agricultural Organization (FAO). In December 2013, the WBF created a special taskforce to deal with the threat posed by TR4.

Despite its massive impact on banana production, we know very little about the pathogen that is causing Fusarium wilt disease. We don’t know how it spreads, why the new TR4 is so aggressive, or how we can stop it.

Fusarium Wilt symptom

Fusarium Wilt symptoms in the discolored banana corm.

Breeding bananas is incredibly tedious, because edible cultivars are sterile and do not produce seeds. I am therefore exploring other ways to engineer resistance in banana against Fusarium wilt. As a scientist in the 2Blades group at The Sainsbury Laboratory, I am investigating how we can transfer resistance genes from other crop species into banana and, more recently, I have been investigating bacteria that are able to inhibit the growth and sporulation of F. oxysporum. These biologicals would be a fast and cost-effective way of preventing or even curing Fusarium wilt disease.

 

Twitter:           @BananarootsBlog

Email:              mailto:sarah.schmidt@tsl.ac.uk

Website:          https://bananaroots.wordpress.com

A taste of CRISPR

Dr Craig CormickThis week’s blog was written by Dr Craig Cormick, the Creative Director of ThinkOutsideThe. He is one of Australia’s leading science communicators, with over 30 years’ experience working with agencies such as CSIRO, Questacon and Federal Government Departments.

So what do you think CRISPR cabbage might taste like? CRISPR-crispy? Altered in some way?

Participants at the recent Society for Experimental Biology/Global Plant Council New Breeding Technologies workshop in Gothenburg, Sweden, had a chance to find out, because in Sweden CRISPR-produced plants are not captured by the country’s GMO regulations and can be produced.

Professor Stefan Jansson, one of the workshop organizers, has grown the CRISPR cabbage (discussed in his blog for GPC!) and not only had it included on the menu of the workshop dinner, but also had samples for participants to take away. Some delegates were keen to pick up the samples while others were unsure how their own country’s regulatory rules would apply to them.

 

 

Regulatory issues

The uncertainty some delegates felt about the legality of taking a CRISPR cabbage sample home was a good demonstration of the diversity of regulations that apply – or may apply – to new breeding technologies, such as CRISPR and gene editing – and there was considerable discussion at the workshop on how European Union regulations and court rulings may play out, affecting both the development and export/import of plants and foods produced by the new technologies.

A lack of certainty has meant many researchers are unable to determine whether their work will need to be subjected to costly and time-consuming regulations or not.

The need for new breeding technologies was made clear at the workshop, which was attended by 70 people from 17 countries, with presentations on the need to double our current food production to feed the world in 2050 and reduce crop losses caused by problems such as viruses, which deplete crops by 10–15%.

The two-day workshop, held in early July, looked at a breadth of issues, including community attitudes, gene editing success stories, and tools and resources. But discussions kept coming back to regulation.

Outdated regulations

Regulations of gene technologies were largely developed 20 years ago or so, for different technologies than now exist, and as a result are not clear enough for researchers to determine whether different gene editing technologies they are working on may be governed by them or not.

The diversity of regulations is also going to be an issue, for some countries may allow different gene editing technologies, but others may not allow products developed using them to be imported.

That led to the group beginning to develop a statement that captured the feeling of the workshop, which, when complete, it is hoped will be adopted by relevant agencies around the world to develop their own particular positions on gene editing technologies. It would be a huge benefit to have a coherent and common line in an environment of mixed regulations in mixed jurisdictions.

CRISPR cabbage

And as to the initial question of what CRISPR cabbage tastes like – just like any cabbage you might buy at your local supermarket or farmers market, of course – since it is really no different.

 

Want to read more about CRISPR? Check out our interview with Prof. Stefan Jansson or our introduction to CRISPR from Dr Damiano Martignago.

Brazil’s transgenic sugarcane stirs up controversy

By Luisa Massarani

This article was originally published on SciDev.Net. Read the original article.

[RIO DE JANEIRO] A genetically modified (GM) cane variety that can kill the sugarcane borer (Diatraea saccharalis) has been approved in Brazil,  to the delight of some scientists and the dismay of others, who say it may threaten Brazilian biodiversity.

Brazil is the second country, after Indonesia, to approve the commercial cultivation of GM sugarcane. The approval was announced by the Brazilian National Biosafety Technical Commission (CTNBio) on June 8.

Sugarcane borer is one of the main pests of the sugarcane fields of South-Central Brazil, causing losses of approximately US$1.5 billion per year.

“Breeding programmes could not produce plants resistant to this pest, and the existing chemical controls are both not effective and severely damaging to the environment,” says Adriana Hemerly, a professor at the Federal University of Rio de Janeiro, in an interview with SciDev.Net.

“Studies conducted outside Brazil prove that protein from genetically modified organisms harms non-target insects, soil fauna and microorganisms.”

Rogério Magalhães

“Therefore, the [GM variety] is a biotechnological tool that helps solve a problem that other technologies could not, and its commercial application will certainly have a positive impact on the productivity of sugarcane in the country.”

Jesus Aparecido Ferro, a member of CTNBio and professor at the Paulista Júlio de Mesquita Filho State University, believes the move followed a thorough debate that began in December 2015 — that was when the Canavieira Technology Center (Sugarcane Research Center) asked for approval to commercially cultivate the GM sugarcane variety.

“The data does not provide evidence that the cane variety has a potential to harm the environment or human or animal health,” Ferro told SciDev.Net.

To develop the variety, scientists inserted the gene for a toxin [Cry] from the bacterium Bacillus thuringiensis (Bt) into the sugarcane genome, so it could produce its own insecticide against some insects’ larvae.

This is a technology that “has been in use for 20 years and is very safe”, says Aníbal Eugênio Vercesi, another member of the CTNBio, and a professor at the State University of Campinas.

But Valério De Patta Pillar, also a member of the CTNBio and a professor at the Federal University of Rio Grande do Sul, points to deficiencies in environmental risk assessment studies for the GM variety — and the absence of assessments of how consuming it might affect humans and animals.

According to Pillar, there is a lack of data about the frequency with which it breeds with wild varieties. Data is also missing on issues such as the techniques used to create the GM variety and the effects of its widespread use.

Rogério Magalhães, an environmental analyst at Brazil’s Ministry of the Environment, also expressed concern about the approval of the commercial transgenic cane.

“I understand that studies related to the impacts that genetically modified sugarcane might have on Brazilian biodiversity were not done by the company that owns the technology,” said Magalhães in an interview with SciDev.Net. This is very important because Brazil’s climate, species, and soils differ from locations where studies might have taken place, he explained.

Among the risks that Magalhães identified is contamination of the GM variety’s wild relatives. “The wild relative, when contaminated with transgenic sugarcane, will have a competitive advantage over other uncontaminated individuals, as it will exhibit resistance to insect-plague that others will not have,” he explained.

Another risk that Magalhães warns about is damage to biodiversity. “Studies conducted outside Brazil prove that Cry protein from genetically modified organisms harms non-target insects, soil fauna and microorganisms.”

Magalhães added that some pests have already developed resistance to the Bt Cry protein, prompting farmers to apply agrochemicals that are harmful to the environment and human health.

This piece was originally published by SciDev.Net’s Latin America and Caribbean desk.

 

This article was originally published on SciDev.Net. Read the original article.

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