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http://www.business-standard.com/article/pti-stories/climate-change-will-have-profound-impacts-on-humankind-obama-114042200194_1.html
Press Trust of India | Washington April 22, 2014 Last Updated at 07:12 IST

Observing that climate change is altering the planet in ways that will have profound impacts on humankind, US President Barack Obama has urged Americans to protect environment for a healthy, sustainable future.

“Today, we face a problem that threatens us all. The overwhelming judgement of science tells us that climate change is altering our planet in ways that will have profound impacts on all of humankind,” Obama said in a proclamation issued yesterday.

“Farmers must cope with increased soil erosion following heavy downpours and greater stresses from weeds, plant diseases, and insect pests.

“Increasingly severe weather patterns strain infrastructure and damage our communities, especially low- income communities, which are disproportionately vulnerable and have few resources to prepare,” he said.

The consequences of climate change will only grow more dire in the years to come, Obama warned, arguing that this is why, last year, he took executive action to prepare US for the impacts of climate change.

“As my Administration works to build a more resilient country, we also remain committed to averting the most catastrophic effects.

He said since he took office, America has increased the electricity it produces from solar energy by more than tenfold, tripled the electricity it generates from wind energy, and brought carbon pollution to its lowest levels in nearly two decades.

“In the international community, we are working with our partners to reduce greenhouse gas emissions around the globe. Along with States, utilities, health groups, and advocates, we will develop commonsense and achievable carbon pollution standards for our biggest pollution source — power plants,” he said.

“Because caring for our planet requires commitment from all of us, we are engaging organisations, businesses, and individuals in these efforts, the US President said.

 

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Praise for new website on African crop pest
03 April 2014 Lancaster University

The UK’s Global Food Security Champion says a Lancaster University website about the African armyworm will help to combat the pest.

Armyworm Network provides important information for farmers in Africa plagued by this devastating pest.

Professor Tim Benton said: “The new website will be a valuable resource for all farmers, governments and others whose lives have been impacted by this major pest of cereal crops in Africa. The forecasts the site provides will be particularly useful for farmers and governments to plan armyworm control activities”.

Armyworms are the caterpillar stage of a moth that migrates throughout sub-Saharan Africa. It is a serious pest of all the main cereal crops, including maize (sweetcorn), rice, millet, sorghum and wheat, as well as pasture grasses, threatening food security in the region.

A cattle farmer from South Africa, who has had armyworms on his pastures for the second year running, said: “I went out early this morning and found hundreds of them on our fields. Last year they destroyed all of our winter grazing (150 hectares), despite our best efforts to control them.

“The website of your university, thousands of kilometres away, was the only comprehensive site I could find with useful information.”

Visitors to the new website can email directly experts in African armyworm biology and control, including Professor Ken Wilson from the Lancaster Environment Centre, who developed the website.

He said, “It is fantastic to be able to launch the new website. The previous site was extremely popular, especially with farmers in Africa and with international agencies wanting to know more about this important crop pest. The new website contains so much more information and is also much easier to navigate”.

The new Armyworm Network provides information and forecasts for large- and small-scale farmers in Africa, as well as for governments, donor agencies, non-governmental organizations, journalists and other stakeholders. It replaces and improves upon its predecessor, which received more than 10,000 visitors from 30 countries during the five years it was operational.

It provides visitors with more information about the biology of this major crop pest, how it can be controlled, current research developing a new biological pesticide against it , press reports of armyworm outbreaks, publications, a live Twitter feed, and regular forecasts issued by international pest monitoring organizations.

http://www.foodsecurity.ac.uk/blog/index.php/author/ken-wilson/

http://www.lancaster.ac.uk/armyworm/

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BY MATTHEW JONES
Friday 4th April 2014, 01:49 London

Whangarei again the site of incursion, only months after authorities deemed another discovery an isolated incident

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New Zealand’s fresh produce industry is again on high biosecurity alert, after the discovery of a second Queensland fruit fly (Q-fly) in Whangarei within three months, according to media reports.

The New Zealand Herald claimed the discovery was made in a surveillance trap located just 400m from where another Q-fly was detected in January. In that instance, heavy restrictions were place on fruit and vegetable trade in the region while a large-scale response operation, involving close to 50 quarantine officials, was undertaken.

New Zealand’s Ministry for Primary Industry’s (MPI) does not believe the two cases are related, after the investigation into January’s incursion determined it was an isolated incident, with no breeding population of Q-fly. A new control area has been established, with the movement of fresh produce around Whangarei again restricted.

“As in January, it is vital we find out if the insect is a solitary find or if there is a wider population in Whangarei,” MPI spokesman Andrew Coleman told SkyNews. “This insect is an unwanted and notifiable organism that could have serious consequences for New Zealand’s horticultural industry and home gardeners. It can damage a wide range of fruit and vegetables.”

January’s two-week response operation cost New Zealand taxpayers almost NZ$1m (US$850,000). New Zealand Green Party biosecurity spokesman Steffan Browning said this week’s discovery questioned the validity of the January campaign and the country’s biosecurity systems in general.

“Given that the last fruit fly was found in the same region only a few months ago it seems likely there is a connection,” Browning told the New Zealand Herald. “If it is the case that this fruit fly is linked to the previous incursion, then it raises serious concerns about MPI ending their January campaign early, before ensuring there were no other fruit fly in the region.”

Kiwifruit Vine Health chief Barry O’Neil said the discovery posed a low risk to the region’s kiwifruit crop, with no orchards within the control area.

http://www.fruitnet.com/eurofruit/article/161150/new-fruit-fly-discovery-in-nz

 

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Yao-Hua Law

 

Speed read
Introduced Philidris ants cut cacao tree yields by aiding a pathogen’s spread

But trees with native ants had greater yields than those without any ants

Farmers who manage ant communities are also managing pests, says expert

 

[KUALA LUMPUR] Native ants living in cacao trees in Indonesia that are often seen as pests in fact seem to boost their yields, a study suggests.

Scientists from Germany, Indonesia and Sweden studying how ant communities affect cocoa yields in Sulawesi found that trees with abundant native ants (Dolichoderus sp.) produced the best yields. In contrast, the yields of cacao trees where ants were excluded were 27 per cent lower and those in which an invasive, foreign ant species (Philidris sp.) were introduced had yields that were 34 per cent lower, the study says.

The results were published last week (4 December) in Proceedings of the Royal Society B.
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“Farmers face many challenges and those who manage ant communities are also managing pests.”

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Stacy Philpott, University of California Arno Wielgoss, a graduate researcher from the University of Göttingen, Germany, and the lead scientist of the 16-month study, tells SciDev.Net that ants live in a mutualistic partnership with the mealybugs — insects that suck plant nutrients and excrete sugar to their guardian ants. But they also protect the cocoa pods from even more destructive pests such as cocoa pod borers and Helopeltis bugs.

The invasive Philidris ants transmit the fungus-like plant pathogen Phytophthora sp. and so the heaviest yield loss, according to the study. These ants collect pieces of Phytophthora-infected cocoa pods to build protective tents over the mealy bugs, it says. The study says that Philidris ants and their tent materials harbour infectious Phytophthora spores with which the ants contaminate fresh cocoa pods.

Indonesia is the world’s third biggest cocoa producer. But increased pest attacks and aging trees have slashed its production this year.

Worldwide, cocoa farmers struggle against severe but geographically limited pest infestations. Ants, which form part of the complex network of life in cocoa farms, are often seen as pests.

Farmers often dislike ants, says Stacy Philpott, an associate professor in agroecology at the University of California, Santa Cruz, who studies insects in another tree crop, coffee. She says that the study is important in advancing the understanding of the ecological roles that ants play.

Wielgoss warns that insecticide spraying could hasten Philidris dominance as “insecticides harm other ant species more than Philidris that are protected in their tents”. The spread of Philidris, he adds, would also be likely to aggravate Phytophthora infection.

Despite this, the effects of having Dolichoderus ants may vary, as a Malaysian Cocoa Board officer says that untreated cacao trees produce only half the yields of trees with ant treatment.

Philpott says: “Translating scientific results into practice can be difficult despite vigorous research. Farmers face many challenges and farmers who manage ant communities are also managing pests.”

This article has been produced by SciDev.Net’s South-East Asia & Pacific desk.

Link to abstract in Proceedings of the Royal Society
References
Proceedings of the Royal Society B doi: 10.1098/rspb.2013.2144 (2013)

http://www.scidev.net/global/agriculture/news/native-ants-help-indonesian-cocoa-yields-1.html

 

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Midwest Producer

No crisis yet: With confirmed resistance, western corn rootworm is worthy of being watched

No crisis yet With confirmed resistance, western corn rootworm is worthy of being watched

 

It isn’t an epidemic and it won’t shut down corn production anytime soon. However, researchers have confirmed that western corn rootworms have developed resistance to Bt corn hybrids that express the Cry3Bba trait in some areas of Nebraska.

University of Nebraska-Lincoln entomologist Lance Meinke said testing in areas of northeast and southwest Nebraska has been conducted over the last few years to determine the cause of “greater than expected rootworm injury,” (GPE) observed in some cornfields.

We started seeing some fields with GPE as early as 2011,” Meinke said. “Our testing has included evaluation of factors other than western corn rootworm that could have caused corn plant damage. We’ve used a bioassay technique to assess the susceptibility of rootworms to various rootworm-active Bt traits. In that process, we collect the western corn rootworm beetles from GPE fields, bring them back to the laboratory and provide an environment for them to lay eggs.”

In their lab, Meinke’s team placed newly hatched

larvae on corn plants at the five-leaf stage under identical conditions.

“We compared survival of GPE collected populations and susceptible control population across the different Bt events on the market,” Meinke said. “We also did some on-farm trials, testing across different rootworm Bt traits to evaluate the level of rootworm control each provided in areas where western corn rootworm populations resistant to the Cry3Bb1 trait have shown up.”

What Meinke and hit team have found is that farmers who have planted corn hybrids that express the Cry3Bb1 trait numerous years in a row have provided a natural selection environment for western corn rootworms.

“When a few of the rootworms survive the Bt corn trait, they reproduce larger numbers of survivors and then the number of individuals in that population that can survive exposure to the Bt trait continues to expand,” Meinke said. “Resistance doesn’t mean the entire field will be a failure. Typically, this scenario begins with just a few survivors and it takes several years for the resistant proportion of a population to increase. That means the level of control the Bt corn hybrid provides in that field may decline over time as more rootworms survive exposure to the Bt trait.”

What researchers like Meinke hope to convey to corn growers is that western corn rootworm resistance isn’t yet a crisis, but it could become much more difficult to manage rootworms if available Bt technologies are overused and resistance to many or all rootworm Bt traits evolves.

“We need to understand that it takes millions of dollars and as long as 10 years to develop a new corn transgenic trait,” Meinke said. “That means, if we lose the technology in our current Bt hybrids, we won’t necessarily have a new one to replace it.”

Alternating tactics on a farm over years is a good way to proactively reduce the chance of resistance occurring or addressing resistance that has evolved.

“Crop rotation is the best tool,” Meinke said. “Generally, one year of soybeans in a field with resistant western corn rootworms wipes out that population. The beetles will lay eggs that hatch, but when larvae try to feed on soybean plants, they don’t find the nutrients they need and they die.”

If some level of crop rotation can be worked into the overall farm plan, over time rootworm populations densities will be suppressed and all tactics will work better.

Corn prices have enticed growers to plant corn-on-corn in recent years, and Meinke said industry specialists know that some operations may face significant risk and/or profit loss if they change their cropping strategy.

“In continuous corn, moving away from single trait Bt hybrids to pyramided trait hybrids (i.e. two or more Bt traits expressed in a hybrid that target the same pest) provides a high level of rootworm control and better resistance management,” Meinke said. “Resistance will likely evolve more slowly to a pyramid hybrid than a single trait hybrid because the insect population has to overcome two Bt traits and not just one.”

Through research, Meinke and his collaborators have found that strategic use of insecticides can be useful to complement other rootworm management tactics, but should be used on an as-needed basis.

“Use of a soil insecticide with a single trait hybrid that is failing the field can improve rootworm protection, but selection for resistance to the trait will continue,” Meinke said. “In most cases, adding soil insecticide over the top of pyramid trait hybrids at planting will not significantly improve rootworm protection but will only add to rootworm management costs.”

Integrated pest management (IPM) plans that utilize a variety of Bt or conventional corn hybrids, crop rotation, careful use of insecticide and other pest management practices give growers the best opportunity to maximize profits and manage western corn rootworm.

“IPM isn’t a use of every tool in every field during one season,” Meinke said. “Working with crop consultants to identify the best integrated plan for each field and farm will bring the best possible results.

“I want to encourage farmers to move away from the ‘silver bullet’ approach with Bt hybrids,” Meinke added. “The Bt traits should be viewed as one of many pest management tools we can incorporate into an effective IPM framework.””

http://www.midwestproducer.com/news/crop/no-crisis-yet-with-confirmed-resistance-western-corn-rootworm-is/article_7adb90b0-99a3-11e3-9d66-001a4bcf887a.html

Copyright 2014 Midwest Producer. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Extra TVUN

Food Security Can Come in Tiny, Wiggly Packages

Reprint |     |  Print | 
Zambian trader Dorothy Chisa sells caterpillars, a popular high-protein delicacy in the southern African country. Credit: Amy Fallon/IPS

Zambian trader Dorothy Chisa sells caterpillars, a popular high-protein delicacy in the southern African country. Credit: Amy Fallon/IPS

LUSAKA, Dec 18 2013 (IPS) - It is known as the land of copper to the outside world, but there’s another c-word that does a roaring trade in Zambia, albeit locally – caterpillars.

On a street corner in the capital Lusaka on a scorching hot day, Dorothy Chisa, 49, is selling the insects, a popular high-protein delicacy in the southern African country. They come raw in different sized pots starting at five Zambian Kwacha (less than one dollar).

“[People] like them very much. They taste very nice, like fish meat. They have vitamins. You pound them and you make a porridge for babies,” the married mother of seven, who can earn 600 Kwacha a day selling caterpillars, tells IPS. Found on the Mopane tree in Zambia’s north, the insects are called ‘Ifishimu’ in Bemba or ‘Ifinkubala’ in the Chewa language heard in the country’s east. The thorns on the black type are more visible than the brown, which vary in size.

After locals pick the living insects from the trees with their bare hands, the creatures are squeezed to discharge the leaves they’ve consumed and put on low heat to roast. In the sweltering Zambian weather, they normally dry within two days.

Locals mix them with nshima, a cornmeal dish and a staple in Zambia, as a snack with tomato and onion on top, and add them to stews. One Lusaka restaurant serves the insects, and at least one safari lodge at Victoria Falls, on the border with Zimbabwe, has them available to tempt mzungus (‘whites’).

Locals flock to the north from Lusaka and other parts of Zambia to buy them in bulk, selling the caterpillars across the country, all year round. This year, attendance in Northern Province schools dropped by more than 70 percent at one stage as students abandoned their lessons to catch the insects, a Zambian newspaper reported last month.

Demand by businessmen and women from urban areas is reported to have pushed up their price, with Kitwe and Lusaka residents camping in villages to snap them up. It was also claimed parents were forcing children to sell caterpillars.

According to a study published in May by the U.N. Food and Agriculture Organisation (FAO), entomophagy – the consumption of insects by humans – supplement the diets of approximately two billion people.

More than 1,900 species, found mostly in tropical countries, are edible. Given their high nutritional value, low emissions of greenhouse gases, low requirements for land and the high efficiency at which they convert feed into food, insects can contribute to food security and help with protein shortages, the report said.

In West Africa, the sheanut caterpillar is consumed, while the sapelli is lapped up in Central Africa (the species are the same as the Mopane but they feed off different trees).

“After buying from us they distribute in other provinces,” Chris Siame, surrounded by tall bags of caterpillars he bought in October and is now selling at bustling Soweto Market in Lusaka, tells IPS. “Some, they come from other countries like Malawi, Zimbabwe, even South Africa to buy them.”

In South Africa, the caterpillars are on the menu of one Johannesburg restaurant. Siame, 32, makes the journey of about 900 km to the north annually for three weeks to buy the insects. “We use the barter system. You give them [traders] clothes,” he explains. “If they don’t want it, you just give them cash.”

He purchased two-kg bags of caterpillars for 40 Kwacha (less than a dollar) each. After trucking them back to Lusaka he’s now selling them for 60 Kwacha a bag. “They taste like an egg yolk. I like them so much,” Siame says.

Their nutritional value is a bonus. According to the FAO, every 100 grammes of dried caterpillars contain about 53 grammes of protein, about 15 percent fat and about 17 percent carbohydrates. The insects are believed to have a higher proportion of protein and fat than beef and fish.

They’re also rich in potassium, calcium, magnesium, zinc, phosphorus and iron, among other vitamins and minerals. “When we go for antenatals, we’re advised to eat them,” another seller, breastfeeding a baby at Soweto Market, tells IPS.

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Halting papaya pest saved over $300 mn for India

              

A natural pest-control plan from US-based Virginia Tech that halted the papaya mealybug – that created havoc in southern India causing mould and stunted growth of several crops – has saved up to $309 million in the first year itself.

For a relatively modest cost of $200,000 during the first year of the intervention, financial loss that would have crossed $1.34 billion over five years has been prevented, said researchers from Virginia Tech.

Led by an Indian-origin crop scientist Rangaswamy ‘Muni’ Muniappan, the Virginia Tech team first discovered this devastating papaya pest – called paracoccus marginatus – in India in 2008 and devised a natural way to combat it.

“India’s first efforts to eradicate the papaya mealybug failed,” said Muniappan, who heads Virginia Tech’s integrated pest management innovation lab programme. “The government and farmers tried spraying pesticides but crop losses kept getting larger. It was clear to us that this was a case not for poisons but for natural, biological controls.” 

The winning intervention was based on three natural enemies of the mealybug – three parasitic wasps imported from Puerto Rico, Mexico, in July 2010. The wasp lays its eggs inside the mealybug larvae, and when the eggs hatch, the young wasps eat the larvae.

Excellent control of the papaya mealybug was obtained within five months, pesticide usage was reduced, and production and income were increased, said the research.

“I’m happy to hear that Virginia Tech scientists conducted an economic analysis. That is so often missing in biological-control projects,” said Marjorie A. Hoy, a University of Florida entomologist.

Source: daijiworld.com 

Publication date: 1/27/2014

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15-Jan-2014

http://www.eurekalert.org/pub_releases/2014-01/mpif-apa011514.php

Contact: Dr. Wilhelm Boland
boland@ice.mpg.de
49-364-157-1201
Max Planck Institute for Chemical Ecology 

Researchers discover an additional level of this insect-plant symbiosis

This news release is available in German.

 IMAGE: Leaves of Acacia hindsiiplants colonized by mutualistic (left) or parasitic ants (right). Plants associated with the mutualistic ant speciesPseudomyrmex ferrugineus are visibly healthier than their neighbors….

Click here for more information.

The biological term “symbiosis” refers to what economists and politicians usually call a win-win situation: a relationship between two partners which is beneficial to both. The mutualistic association between acacia plants and the ants that live on them is an excellent example: The plants provide food and accommodation in the form of food bodies and nectar as well as hollow thorns which can be used as nests. The ants return this favor by protecting the plants against herbivores. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, have now found that ants also keep harmful leaf pathogens in check. The presence of ants greatly reduces bacterial abundance on surfaces of leaves and has a visibly positive effect on plant health. Study results indicate that symbiotic bacteria colonizing the ants inhibit pathogen growth on the leaves. (New Phytologist, January 6, 2014, doi: 10.1111/nph.12664)

Myrmecophytes are plants which live in a symbiotic relationship with ants. The acacia species Acacia hindsii, which is native to tropical dry forests in Central America, is such a myrmecophyte. Its inhabitants are ants of the genus Pseudomyrmex. The ants depend completely on their host plants for nectar and the food bodies rich in proteins and lipids which they require. The acacia also provides shelter, the so-called domatia, in the hollows of its swollen thorns. In return for room and board, mutualistic Pseudomyrmex ferrugineus ants become bodyguards, protecting their host against herbivores and competing plants. However, some ants also benefit from the plant’s services without giving anything in return, such as the parasitic ant species Pseudomyrmex gracilis.

Scientists at the Max Planck Institute for Chemical Ecology have now looked more deeply into the insect-plant interaction, asking whether the tiny bodyguards also provide protection against microbial pathogens. They compared the leaves of acacia plants which were inhabited by either mutualistic or parasitic ants to leaves from which ants had been removed. Intriguingly, the leaves of acacia colonized by parasitic ants showed more leaf damage from herbivores and microbial pathogens than did the leaves that had mutualistic ants. The presence of the right symbiotic partner seemed to have a positive effect on the plant’s health.

 IMAGE: MutualisticPseudomyrmex ferrugineus ants on an acacia plant. The ants love nectar from the plant’s extrafloral nectaries.

Click here for more information.

Analysis of the surfaces of the leaves revealed that the number of plant pathogens as well as of necrotic plant tissues increased considerably when mutualisticPseudomyrmex ferrugineus ants were absent. These plants also showed strong immune responses in the form of an increased concentration of salicylic acid, a plant hormone which regulates defense against pathogens. Detailed analysis of the bacterial composition on the surfaces of the leaves suggested that the presence of mutualistic ants changed the bacterial populations and reduced harmful pathogens. Although far less pronounced, this effect could also be observed in parasitic ants.

How antimicrobial protection is transferred from ants to plant is still unclear. Chilean researcher Marcia González-Teuber, first author of the publication, suspected that microorganisms associated with the ants might play a role. Because acacia leaves are touched mainly by ants’ legs, she extracted the legs of mutualistic and parasitic ants and tested the effect of the extracts on the growth of bacterial pathogens in the lab. Plant pathogen Pseudomonas syringae was sensitive to the application of leg extracts of both ant species and its growth was inhibited. In the next step, the scientist isolated and identified bacteria from the legs of the ants. In lab tests, bacterial strains of the genera Bacillus, Lactococcus, Pantoeaand Burkholderia effectively inhibited the growth of Pseudomonas bacteria isolated from infected acacia leaves. Interestingly, some of the bacterial genera associated with the ants are known to produce antibiotic substances.

The Jena researchers have thus added another level of interaction to the symbiosis between ants and their host plants. “Such mutualistic relationships are much more complex than previously thought. In the future, we will have to include bacteria and other microorganisms in our considerations,” says Wilhelm Boland, head of the Department of Bioorganic Chemistry at the Max Planck Institute. Studies on symbiotic relationships between ants and myrmecophytic plants should not overlook the role of bacterial partners that help the ants protect “their” plants. [AO]

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Original Publication:

González-Teuber, M., Kaltenpoth, M., Boland, W. (2014). Mutualistic ants as an indirect defence against leaf pathogens. New Phytologist, DOI 10.1111/nph.12664

http://dx.doi.org/10.1111/nph.12664

Further Information:

Prof. Dr. Wilhelm Boland, Max Planck Institute for Chemical Ecology, E-Mail boland@ice.mpg.de, Tel.: +49 3641 57 1201

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http://www.youtube.com/watch?v=f4W1d0Cqm_Y or goo.gl/zIgmeg

 Published on Jan 17, 2014

A workshop in Ethiopia sponsored by the Integrated Pest Management Innovation Lab at Virginia Tech shared current knowledge about Tuta absoluta and its spread, as well as methods of controlling the pest.

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AgProfessional.com
Purdue University  |   December 19, 2013

Purdue University researchers have confirmed the long-held hypothesis that sorghum deters insects from feeding on its leaves by releasing hydrogen cyanide.

Mitch Tuinstra and Brian Dilkes found that insects preferred the leaves of a mutant sorghum plant with an abnormally slow release of cyanide to those of a wild-type sorghum plant with a normal cyanide-release rate. Fall army worms fed on the leaves of the mutant sorghum even though the leaves contained similar levels of dhurrin – the chemical compound responsible for synthesizing hydrogen cyanide – as those in normal sorghum plants.

“This study separates for the first time the accumulation of dhurrin from the release of hydrogen cyanide,” said Dilkes, assistant professor of horticulture and landscape architecture. “Both the mutant and normal sorghum plants contain dhurrin, but it’s the rate of cyanide release that causes the insects to avoid one in favor of the other. It’s a beautiful interaction between animal behavior and plant chemistry.”

Sorghum bicolor, the cultivated species of sorghum, is a critically important cereal grass used for food and animal forage in many parts of the developing world and is a promising bioenergy crop in the U.S. Its ability to thrive in arid environments makes it a more water-efficient crop than corn.

While the grain of sorghum is edible, its leaves can sometimes contain levels of hydrogen cyanide that are toxic to humans and animals. Livestock producers have long known that feeding sorghum leaves harvested at certain growth stages, and particularly under stress conditions such as drought, can result in cyanide poisoning of livestock. When properly managed, however, sorghum leaves can be safe forage for cattle.

Identification of genes that control cyanide production and release could lead to the development of cyanide-free sorghum plants.

Tuinstra and Dilkes identified a sorghum mutant with an exceptionally slow cyanide-release rate. They located the gene responsible for the defect by using next-generation sequencing, a technique that randomly generates short sequences from a genome – the total genetic content of an organism – and stitches them back together. Next-generation sequencing works like a text editor, said Tuinstra, professor of plant breeding and genetics.

“It’s just like taking a 10-word sentence from a book and asking where it belongs,” he said. “It finds the location of a specific sequence inside the species genome. The mutation is like a misplaced period in the middle of a sentence – it signals the reader to stop. In the case of the sorghum mutant, it halts the production of a functional protein.”

The sequencing technique allowed Tuinstra and Dilkes to identify the single nucleotide within the sorghum genome of 790 million base pairs that slowed the release of cyanide in the mutant plant.

“This study is an example of how new methods in DNA sequencing can now be used to unlock the genetic mechanisms of sorghum performance,” Tuinstra said.

After cloning the mutant, the researchers tested insect feeding preference by releasing fall army worms onto mutant and normal sorghum plants. Though both types of sorghum contained normal levels of dhurrin, the insects avoided the normal sorghum plants, settling and feeding on the leaves of the mutant sorghum instead. While the mutant contains the compounds necessary to generate cyanide, it cannot release cyanide quickly enough to ward off pests, Tuinstra said.

Next-generation sequencing is more often used in plant species with genomes much smaller than sorghum. The study clears the way to use advanced sequencing techniques to identify genes and gene functions in plants with large genomes, Dilkes said.

“We’ve demonstrated that these sequencing tools are robust enough to apply to organisms with complex genomes,” he said. “If we can use them in sorghum, we can use them in other crops. In terms of identifying genes of interest in complex organisms, we’re open for business.”

The paper was published in Genetics and is available athttp://www.genetics.org/content/195/2/309.full.pdf+html?sid=39121ec4-c3f7-43f8-a7d0-8e5107d03b40 .

The research was conducted using funds from the U.S. Department of Energy, the International Sorghum and Millet Collaboration Research Support Program and an Agriculture and Food Research Initiative Competitive Grant.

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