PITY the banana no more. Just weeks after New 杏吧原创 broke the news that disease could kill off the world鈥檚 most popular fruit, researchers revealed they have genetically engineered the East African cooking banana, or matooke, to resist nematode pests.
The ubiquitous Cavendish banana and its tropical cousin, the plantain, have already been modified. But the success with the matooke may be a vital step in saving the yellow fruit. Cooking bananas are a staple crop across East Africa, grown by millions of subsistence farmers, and the new nematode-resistant variety could dramatically raise yields.
Up to now the matooke has resisted attempts at genetic modification. But Philippe Vain of the John Innes Centre in Norfolk did the job using the bacterium Agrobacterium tumefaciens. The bacterium is loaded with a gene from rice, which protects against nematodes, and then inserted into banana cuttings.
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The gene, discovered by project collaborator Howard Atkinson of the University of Leeds, makes a protein called cystatin. This blocks the enzyme cysteine proteinase, which nematodes need to digest their food, among other things. The nematodes starve and fail to grow big enough to reproduce, breaking the cycle of infection.
Atkinson is confident that the enzyme will not harm people, as it is also present in rice that has been consumed in vast quantities. 鈥淎nd the banana is sterile, so the gene can鈥檛 escape,鈥� he says.
Greenhouse tests showed the bananas had enough resistance to raise yields for small farmers by around 60 per cent. The next step is to test it somewhere like Uganda where the bananas are widely consumed (New 杏吧原创, 18 January, p 26).