Research helps to prevent virus damage in sweet potato crops

A research team from the University of Helsinki discovered that a virus which decreases the sweet potato crops of developing countries paralyses the defence of the plant.

Sweet potatoes

"When we understand how the disease emerges, we can find ways to prevent it," says team leader and Academy Professor Jari Valkonen.

For poor populations in developing countries, sweet potato is an important food plant, which is also able to yield crops in barren and dry environments. The only major threat for the cultivation of the plant is a disease caused by a mixed virus infection where the crini virus breaks down the sweet potato’s defence against several different viruses.

The research team led by Valkonen found in the crini virus an enzyme which destroys mini-RNA molecules required in the virus defence of the plant. This RNaseIII enzyme is alone capable of paralysing the defence of the plant.

The significance of the plant in the emergence of the disease was discovered by producing transgenic sweet potatoes. In this task, the research team was assisted by colleagues working for the Peru-based International Potato Center.

"Gene transfer work was carried out patiently in Peru. After four years, we had enough plants to use for the research," says Valkonen, praising the partners who helped to find the solution.

The next step for the research team is to find out which gene of sweet potato is subjected to the impact of the virus. "Then, for cultivation, we will seek individual plants where the gene has transformed so that it is immune to the virus."

Suitable plants are not looked for in fields, but from the sweet potato gene bank of the International Potato Center.

Valkonen is looking forward to a moment taking place in about five years when sustainable sweet potato variants resulting from the research can be planted in the fields of small farmers based in East Africa.

The research results were published in the “Proceedings of the National Academy of Sciences of the USA” journal in June.

Read more:
Department of Applied Biology >>
PNAS publication’s article online >>
International Potato Center >>

Text: Marja Lintula
Photo: Wikipedia Commons
16.7.2009
www.helsinki.fi/digitalcommunications

Translation: AAC Noodi Oy


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