Parasitic wasps switch off the immune systems of fruit flies by draining calcium from the flies’ blood cells, a finding that offers new insight into how pathogens break through a host’s defenses.

“We believe that we have discovered an important component of cellular immunity, one that parasites have learned to take advantage of,” says Emory University biologist Todd Schlenke, whose lab led the research.

The Proceedings of the National Academy of Sciences (PNAS) published the results, showing how a wasp version of a conserved protein called SERCA, which normally functions to pump calcium from the cell cytoplasm to the endoplasmic reticulum, can block a host’s cellular immune response.

“Before our study, there were hints that calcium signaling was important for blood cell activation following infection, but the fact that a parasite actively suppresses this signaling shows how important it is, Schlenke says. He adds that the insects can serve as a model for more complex human immune systems.

“It’s incredible the way the wasps use a protein in their venom to control the flies at a molecular level,” says Nathan Mortimer, a post-doctoral fellow in the Schlenke lab who conducted the experiments. “Instead of killing the fly immune cells, the wasps actually take over blood-cell signaling, manipulating the host’s behavior from the bottom up.”

The research team also included Emory biologist Balint Kacsoh; Jeremy Goecks and James Taylor, from Emory’s departments of biology and mathematics and computer science; and James Mobley and Gregory Bowersock of the University of Alabama, Birmingham.

Fruit flies and the tiny wasps that parasitize them have co-evolved complex strategies of attack and defense. The wasps inject their eggs into the body cavities of fruit fly larvae, along with venom that aims to suppress the flies’ cellular immunity. If the flies fail to kill the wasp egg, a wasp larva hatches inside the fruit fly larva and begins to eat its host from the inside out.

“The wasp larvae have these sharp appendages, like the fingers of Edward Scissorhands, that they use to stick into the fly tissue and start eating,” Mortimer says. “It’s a brutal process.”

In previous research, the Schlenke lab has shown how fruit flies sometimes use alcohol in rotting fruit as a drug to kill the wasps.

In the current study, the researchers focused on the molecular attack strategies of the wasps. After sequencing the transcriptome of the newly described wasp species Ganaspis sp.1, they took a proteomic approach to identify peptide sequences out of the wasp’s venom gland, which they could then link back to full-length transcript sequences.

“We found that the venom of Ganaspis sp.1 is a toxic cocktail of 170 different proteins,” Schlenke says, “but the most prominent component was the SERCA calcium pump protein. That really surprised us.”

Calcium pumps are found in the membranes of every living cell of every animal, and are needed to maintain ionic homeostasis and cellular stability. One type of pump moves calcium ions out of the endoplasmic reticulum and into the cytoplasm where they transmit signals that activate other proteins. The SERCA calcium pump operates in the opposite direction, sucking calcium ions out of the cytoplasm and back into storage.

“We wondered why the wasps would inject the flies with a protein that the flies already have, and that every cell needs to function,” Schlenke says. “How could that be an infection strategy?”

The researchers knew of studies suggesting that a calcium burst in cytoplasm is associated with the activation of human blood cells. They wondered if something similar was happening with the flies.

Mortimer conducted experiments on a transgenic fly strain with cells that fluoresce in the presence of calcium. He found that the fly blood cells release a burst of calcium into their cytoplasm, and that this activates the blood cells to start homing in on the wasp eggs. Genetically increasing or decreasing blood-cell calcium levels makes the flies more or less resistant to the parasite infection.

“The wasp venom prevents this calcium burst, and it’s like the fly blood cells don’t realize they’re supposed to be responding to infection,” Mortimer says. “The venom essentially sucks the calcium out of the fly’s blood cells.”

The experiments showed that the wasp venom is specifically targeted to the fly blood cells, and has no effect on other cells.

An unresolved question is how a SERCA protein, which is hydrophobic and normally resides in an oily membrane, moves out of a wasp venom cell and makes its way into a fly blood cell.

“We have no idea how it works,” Schlenke says, “but somehow this calcium pump moves through all these environments and finds its way into its target cells.”

The researchers hypothesize that virus-like particles in the wasp’s venom may be involved. “If they aren’t really viruses, they seem to be some virus-like thing that the wasp has invented,” Schlenke says. “It’s pure speculation, but we think maybe the wasps use these particles as delivery vehicles for the calcium pumps.”

Previous research has established that fruit fly immune signaling pathways have homologues in humans, making fruit flies a valuable model for learning about human immunity. That work led to the award of the 2011 Nobel Prize in physiology or medicine to Jules Hoffmann, a fruit fly immunologist.

Studying the wasp-fly battle for survival at the molecular level provides a powerful new tool for unlocking more secrets of immunity that could apply to human health, Mortimer says.

“I’m also interested in using the flies to understand more about the immune systems of mosquitos and other insect vectors of human disease,” he says. “If we could somehow boost vector insect immunity, it could decrease transmission of human disease like malaria.”

On the night of May 13 a documentary called ”The Fruit Hunters” premiered at the Laemmle Monica 4. The fascinating (and taste-tempting) film was directed by Yung Chang and features actor Bill Pullman, who has been cultivating a vertical orchard at his home in the Hollywood Hills for nearly 20 years.

Now that the rains are just around the corner, prepare your fruit tree planting materials. In doing so, don’t just get any available seedling. Fruit trees take several years before they bear fruit so it is important that what you plant are the varieties with superior fruits.

Here are a few pointers you might consider. Of course, you should plant grafted planting materials to make sure your trees bear fruit early and that you know before hand the kind of fruit you will expect.

Here are a few varieties you might consider planting these coming weeks. Say you want to plant avocado. If so, select a variety that produces fruits with excellent eating quality. One such variety is the so-called Super Avocado which produces fruits that weigh as much as one kilo and the flesh is fine-textured, yellowish and sweetish, and without fibers.

If you are going to plant rambutan, you might as well plant the varieties with proven productivity and with excellent eating quality. There are three that we particularly like. One of them is the R-5 which produces big red fruits with very smooth white flesh that separates readily from the seed. Another is the Super Red which is also very attractive, high-yielding and with good eating quality. Another variety that is highly adaptable to local conditions is the Rongrein which originally came from Thailand.

What is good about rambutan is that the trees always bear fruit every year as long as they are taken care of. And one can stagger the fruiting, just as we have done with our own trees. Right now, we are harvesting from three trees. Several other trees will be harvestable in a month’s time. And there are some that are just flowering.

Chicos are also a favorite of many Filipinos. If you want something that is decorative and is very prolific, plant the variegated chico. The fruits are small but they are very sweet. Then there is the Mapino variety, a selection by the Institute of Plant Breeding. This produces fruits that weigh 120 grams each or more and the flesh is so smooth and fine-textured. Another good variety is the Yusepeng chico which was named after the late Carlos Yusepeng, a rare fruit collector from Gen. Santos City.

In any case, being a superior variety is just one consideration. What is equally important is to take good care of whatever fruit tree you plant. Fertilize them adequately. Don’t allow them to be overtaken by weeds, especially when they are still small.

The Central Regional Minister, Mr Samuel Sarpong, has launched a GH¢1.2 million organic Sugar-Loaf Pineapple growing project at Essarkyir in the Ekumfi District of the Central Region.

The project, which is jointly sponsored by Japan and the Central Regional Development Commission, (CEDECOM) is aimed at expanding and improving sugar-loaf pineapple cultivation in order to reduce poverty in the district.

The two-year project would assist 277 small-holder-farmers in the district to cultivate one-acre pineapple farm each, and also create access to the export market.

The launch was on the theme: “Stimulating High Economic Growth through Pineapple Production.”

Mr Sarpong, who addressed a durbar of chiefs and people of the area, commended the Japan the constant support to Ghana and urged the beneficiaries to make maximum use of the funds provided to increase their products as well as improve upon their living standards.

He said the money is a revolving fund, and so the beneficiaries should make sure it yields the needed profit for others to profit from it.

Mr Sarpong also urged them to take advantage of the project to produce quality pineapples that would meet the international market standards.

Mr Edwin Nii Lantey Vanderpuye Deputy Minister of Trade and Industry said the government has an agricultural base policy that aims at ensuring the production of the necessary raw materials to feed the nation’s industries.

He said pineapple cultivation would be given the necessary boost to increase production so as to meet local and international demands.

Mr Spencer Taylor Acting Executive Director of CEDECOM noted that pineapple growing has been identified as the pre-occupation and the life blood of the people of Ekumfi although the farmers are confronted with challenges which position them below the poverty line.

He said pineapple cultivation in the area is saddled with challenges including pest infestation and unavailability of market for the product, which leads to huge post- harvest losses and low pricing of the commodity.

Mr Taylor said the commission contributed GH¢200.00 towards the projects and that 10 communities would be beneficiaries of the project.

Mr Abeiku Crentsil Member of Parliament for Ekumfi Constituency commended CEDECOM for making provisions for the beneficiaries to retain 30 per cent of the revenue.

This he noted would help with the development of the area.

Mr Crentsil appealed to the government and civil society organisations to provide the area with a processing factory so as to help reduce post-harvest losses.

Safohen Nana Imprem VI, Acting President of Ekumfi Traditional Council, who presided over the event appealed for the reconstruction of the Otuam – Ekumfi road as well as some feeder roads in the District.

Myanmar exported mangoes and watermelons for the fist time to Singapore last week, according to Myanmar Fruit and Vegetable Producers and Exporters Association.

Myanmar has started mango export to Singapore on May 7, said Lei Lei Oo, Vice Chairperson of Myanmar Fruit and Vegetable Producers and Exporters Association.

“Singapore has accepted mangoes from Myanmar. Now, we have sent 3 tonnes of mango. More will be exported depending on our capacity. We aim to export mangoes until its season ends,” said a director of Myanmar Golden Produce Company which made the shipment.

Myanmar has also introduced seedless watermelons to Singapore. Soe Than Min Din, Chairman of Myanmar Fruit and Vegetable Producers and Exporters Association, said, “Seedless watermelons have been traded to China through the border for five years. We earlier attempted to export them with air shipment, but failed to do so due to the fruits’ weight. Now, we have started sea shipments to Singapore. This is more profitable than trading watermelons through the border.”

In the past, Myanmar exported its fruits mainly to China, but it initiated market expansion three years ago. It has targeted Singapore, Malaysia and Thailand, and has participated in international fruit festivals around the world.

Philadephia Gov. Corbett and senior agricultural officials from Chile gathered at Packer Avenue Marine Terminal in South Philadelphia on Tuesday to mark what they say is a growing Chilean and South American fruit trade to Philadelphia.

On a pier behind them, the Bahia Castillo, a refrigerated cargo ship, was unloading fresh Chilean fruit. About 10,000 pounds of the grapes, kiwis, apples, and pears were donated to Philabundance, the hunger relief group, which took the fruit by truck to area food pantries.

A delegation that went with Corbett last month on a trade mission to Chile and Brazil met with Chilean Agricultural Minister Luis Mayol Bouchon and invited him to Philadelphia.

“Historically, the Port of Philadelphia was the principal port for the United States for all exports of fresh fruit from Chile,” Mayol said.

About 40 percent of all Chilean agricultural exports to the United States pass through the ports on the Delaware River, and 86 percent of those exports are fruit.

Grapes, apples, pears, cherries, and citrus fruit from Chile are “winter” fruit, and begin arriving here in early December. An 8.8-magnitude earthquake in Chile in 2010 slowed fruit shipments, but after the government and people of Chile made repairs, the fruit harvest and shipments have returned to previous volumes.

“Chile is Pennsylvania’s largest out-of-country provider of fruit and wine,” Corbett said. “This port puts the goods of any importer within a day’s drive of almost half the population of our nation.”

Philadelphia handles $680 million a year in imports from Chile. “As I told the agricultural minister, we love Chile, and hope to continue to do business with them for a long time,” said Charles Kopp, chairman of the Philadelphia Regional Port Authority.

The way fruit is shipped is changing from “break bulk” cargoes loaded individually on pallets to giant containers such as truck trailers.

About 533,000 metric tons of Chilean fruit arrive annually at ports on the Delaware River, said Sean Mahoney, the port authority’s marketing director.

The Philadelphia port handles 44 percent of the fruit on the river. The other 56 percent goes to South Jersey and Wilmington ports.

“It’s a very, very important trade to the region,” Mahoney said. “Other ports, like Miami in South Florida, are looking closely at ways to try to take the cargo out of this area and move it up by train to markets in the Northeast.

“We want very much to grow the fruits and vegetables that are coming in, and hold onto this tremendous opportunity that we have.”

KARACHI: Fruit and rice exporters have expressed the optimism the newly government elect would formulate policies, which would pave way for enhancing country’s export to substantial level.

This step would ultimately result in sustainable economic recovery the country badly needed at this crucial juncture of its history.

Waheed Ahmad President All Pakistan Fruit and Vegetable Exporters Association (PFVA) while congratulating Pakistan Muslim League PML (N) on its clear majority in the lower house of parliament hoped this victory would result in sustainable economic recovery of the country.

For the last many years, the country is lagging far behind in trade and export field mainly on account of unsustainable and ill-directed policies resulting in stagnation of fruit and vegetable exports.

If the new government focuses on horticulture sector for next 3 to 4 years, this sector has the potential to boost existing $500 million export to more than $5 billion level a year.

In this regard Research and Development (R&D) sector is most vital for enhancing existing fruit and vegetable yield to substantial level as the current annual produce has been showing constant decline on account of host of factors.

Unless new varieties of fruit and vegetables are not introduced through rigorous efforts by the scientists, which would help improving existing standard of exporting material, the decline in both sectors exports would continue haunting the national economy.

More than 50 percent of national economy is agriculture based and any neglect in this regard can spell critical consequences for the economy of the country.

Referring to significance of value addition, he said it could also substantially boost demand of Pakistani fruits and vegetables across the globe.

Rice Exporters Association (REAP) Chairman Jawaid Ghouri in his reaction urged the newly elected leadership of PML (N) to ensure special measures not only to push rice exports of the country but to restore overall economic activities of the country facing decay for the last many years.

He said during the last many years, rice exports have emerged as major revenue earning sector of the country, which ranges around $2 billion but to sustain this ambitious goal appears to be a monumental task, which acutely requires government help.

Exploring new markets across the globe for enhancing rice export also requires official help which can be achieved through strong coordination and enhanced working between Trade development Association of Pakistan (TDAP) and REAP.

TEHRAN - Iran imported 481,000 tons of fruits, valued at $354 million, in the past Iranian calendar year, which ended on March 20, ILNA quoted Iranian Customs Administration Director Abbas Memarnejad as saying on Sunday.

The annual Konkan Fruit Festtraditionally held in the capital city of Panaji will be held at the BPS club in Margao this year. Thekonkan fruit fest-2013 will be held from May 10 to May12 .

The fest is a popular event that celebrates anamazing diversity of local fruits of the Konkan region. This provides a platform to the fruit growers to exhibit their fruits and consumers to learn more about them.

Miguel Braganza, secretary of the Botanical Society of Goa, said “There will be a lot of fun and excitement at the Konkan Fruit Fest-2013. Various new features have been introduced at the event including an ICAR demonstration on vermi-composting, mushroom cultivation and grafting .”

“We have often had requests from both farmers and citizens of South Goa to bring the fest to Margao so that others can also participate and be a part of the event. I am looking forward to seeing a greater number of participants at the event,” Braganza said. ”

Various competitions on processed fruit products, ranging from pickle, candy, jam and syrup to cakes and wines will also be held. A fruit eating and fruit carving competition will also be a part of this three-day festival.

“I have been attending this festival for several years now. I think it is a fantastic exhibition of fruits. Also, children learn a lot about the various local fruits. Iam really looking forward to attending this year’s edition of the festival,” said Suvarna Fonseca, a lecturerfrom Margao.

Citrus Australia, the peak grower group, is hopeful Indonesia will lift import restrictions on fruit by July, just as the mandarin season in Queensland kicks off.

Overall citrus exports to Indonesia were worth $14 million last year, before Indonesia imposed quotas in November, in a bid to support its own growers.

Indonesia announced last week it will ease those restrictions, in response to a complaint by the United States.

Judith Damiani, chief executive of Citrus Australia Limited, says a delegation of citrus and grape exporters met trade officials in Jakarta last week, and negotiations are still at a sensitive stage.

“The export situation seems to be changing every day,” she said.

“(Indonesia is) in our top five export markets, it’s particularly important for Australian mandarins.

“Last year, mandarin exports was valued at close to $9 million.

“For oranges, Australian navel exports, it’s close to $5 million.

“Of course Indonesia is a growing market.”

The Indonesian trade ministry’s changes to horticulture imports are expected to be effective from July this year.

Indonesia has also been the most significant apple market for Australia, worth $1.45 million in 2010, but the import restrictions have reduced that dramatically.

Now Apple and Pear Australia Ltd is hosting a delegation from emerging Asian markets, excluding Indonesia.

Claire Fitchett, marketing manager with the peak apple group, says it’s the first time its hosted retailers from China, Singapore, Malaysia and Thailand.

“We just think it’s time to start working aggressively in our Asian markets.

“It’s a perfect time of year, with pink ladies being harvested.”