The findings could help ease hunger in many countries where people rely heavily on the cassava plant (Manihot esculenta) as a primary food source, said Richard Sayre, the study's lead author and a professor of plant cellular and molecular biology at Ohio State University.
The researchers used a gene from the bacterium E. coli to genetically modify cassava plants. The plants, which were grown in a greenhouse, produced roots that were an average of 2.6 times larger than those produced by regular cassava plants.
"Not only did these plants produce larger roots, but the whole plant was bigger and had more leaves," Sayre said. Both the roots and leaves of the cassava plant are edible.
Cassava is the primary food source for more than 250 million Africans ?about 40 percent of the continent's population. And the plant's starchy tuberous root is a substantial portion of the diet of nearly 600 million people worldwide.
Sayre said he hopes to offer these plants to countries where cassava is an important crop.
The current study appears in the online early issue of the Plant Biotechnology Journal. Sayre collaborated with Ohio State colleague Uzoma Ihemere and scientists from BASF Plant Science in Research Triangle Park, N.C., and BARC-West in Beltsville, Md., who formerly worked on this project in his laboratory.
Sayre said that cassava produces sugar more efficiently than any other cultivated plant.
"We wanted to find a way to help the plant redirect that excess sugar and use it to make starch," Sayre said.
The researchers used a variety of cassava native to Colombia (cassava was brought to Africa from South America by the Portuguese in the 1500s.) They inserted into three cassava plants an E. coli gene that controls starch production. A non-modified fourth plant ser
Source:Ohio State University