Genes from sweet pepper to fortify African banana against devastating wilt disease

Aug 06, 2010

In a major breakthrough, crop scientists announced today the successful transfer of green pepper genes to bananas, conferring on the popular fruit the means to resist one of the most devastating diseases of bananas in the Great Lakes region of Africa.

The Banana Xanthomonas Wilt (BXW) costs banana farmers about half a billion dollars worth of damage every year across East and . The leaves of affected crops turn yellow and then wilt, and the fruit ripens unevenly and before its time. Eventually the entire plant withers and rots.

Dr. Leena Tripathi, a biotechnologist with International Institute of (IITA) and lead author of the paper, said there is still a long way to go before the transgenic bananas find their way onto farmers' fields, but she called the breakthrough "a significant step in the fight against the deadly banana disease."

The transformed bananas, newly-infused with one of two proteins from the green pepper, have shown strong resistance to Xanthomonas wilt in the laboratory and in screen houses. The researchers are poised to begin confined field trials in Uganda soon.

Some of the findings on the protective impact of the two proteins—plant ferredoxin-like amphipathic protein (Pflp) and hypersensitive response-assisting protein (Hrap)—were published recently in the journal Molecular Plant Pathology.

"The Hrap and Pflp genes work by rapidly killing the cells that come into contact with the disease-spreading bacteria, essentially blocking it from spreading any further," Tripathi said. "Hopefully, this will boost the arsenal available to fight BXW and help save millions of farmers' livelihoods in the Great Lakes region."

The novel green pepper proteins that give crops enhanced resistance against deadly can also provide effective control against other BXW-like bacterial diseases in other parts of the world. Tripathi adds that the mechanism known as Hypersensitivity Response also activates the defenses of surrounding and even distant uninfected banana plants leading to a systemic acquired resistance.

Scientists from the IITA and the National Agricultural Research Organisation (NARO) of Uganda, in partnership with African Agricultural Technology Foundation (AATF), will soon begin evaluating these promising new banana lines under confined field trials. The Ugandan National Biosafety Committee recently approved the tests, which can now move forward.

The genes used in this research were acquired under an agreement from the Academia Sinica in Taiwan.

The highly destructive BXW affects all varieties, including the East African Highland bananas and exotic dessert, roasting, and beer bananas. The crop is also under threat from another deadly disease, the banana bunchy top.

Dr. Tripathi says that there are presently no commercial chemicals, biocontrol agents or resistant varieties that can control the spread of BXW. "Even if a source of resistance is identified today," Tripathi said, "developing a truly resistant banana through conventional breeding would be extremely difficult and would take years, even decades, given the crop's sterility and its long gestation period."

BXW was first reported in Ethiopia 40 years ago on Ensete, a crop relative of banana, before it moved on to bananas. Outside of Ethiopia, it was first reported in Uganda in 2001, then rapidly spread to the Democratic Republic of Congo, Rwanda, Kenya, Tanzania, and Burundi, leaving behind a trail of destruction in Africa's largest banana producing and consuming region.

BXW can be managed by de-budding the banana plant (removing the male bud as soon as the last hand of the female bunch is revealed) and sterilizing farm implements used. However, the adoption of these practices has been inconsistent at best as farmers believe that de-budding affects the quality of the fruit and sterilizing farm tools is a tedious task.

The research to fortify against BXW using genes from sweet pepper was initiated in 2007.

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Provided by Burness Communications

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User comments : 5

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newsreader
not rated yet Aug 06, 2010

Does this type of work concern anyone? What are the chances the solution will end up being worse than the original problem? This reminds me of attempts to control unwanted pests by introducing new species into a habitat.
Djincs
not rated yet Aug 07, 2010
If the solution is worse this is not a solutio, and there wont be any effect because thats why a field trials are conducted before the planting of big area.

"Hopefully, this will boost the arsenal available to fight BXW and help save millions of farmers' livelihoods in the Great Lakes region."
And the resistance is 100% natural, they take a protein which desolve in to the soil , no pesticides, just briliant solution for this type of problems.
I just cant get why is all this stupid critisism.
"This reminds me of attempts to control unwanted pests by introducing new species into a habitat."
No it is nothing like that the cultivated banana cant escape into the wild and to harm the other species, and the bananas we eat are triploids they have 3n copies from every hromosome(they cant reproduse by seeds) it cant crossbread with the wild ones. Great job!
Djincs
not rated yet Aug 07, 2010
How come people say only bad things for GMO or dont say anything at all! Just leave your prejudices for 5 sec while you read this!
Scott_T
not rated yet Aug 07, 2010
It'd be nice if they could bring back some of the older varietys of bananas too.
david_42
5 / 5 (1) Aug 07, 2010
Bananas are propagated via cuttings. They are virtually sterile and there is no way the genes can be transferred into the wild. They can't "infect" non-GM bananas for the same reason. The cuttings are clones, not genetic mixes. Any plant that does not carry the new gene, never will.