Seed World

Research Finds that Sugar Helps Corn Cope with Drought

New research shows that genetically altering the amounts of a naturally occurring sugar can substantially improve the yield of drought affected corn. The research, a collaborative project between Syngenta and Rothamsted Research, is published in the journal Nature Biotechnology.
Drought significantly impacts crops worldwide, hitting poorest farmers most dramatically. In the United States and even in the United Kingdom predictions are that water will become increasingly limiting for crops.
Syngenta scientists introduced a single transgene to alter the amounts of a naturally occurring sugar, called trehalose 6-phosphate or T6P, in a highly tissue-specific manner. The plants were evaluated for several years in maize field trials in North and South America.
In doing so, corn under no or mild drought, increased in yield between 9 percent and 49 percent, and corn under severe drought, increased in yield between 31 percent and 123 percent, according to Syngenta.
“Our collaboration with Rothamsted Research has given us significant new insights into how our corn trait functions to improve response to drought in the field,” says Michael Nuccio, Syngenta principle research scientist and the study leader. “This knowledge will be important for designing the next generation of crop varieties able to remain productive under water-limiting conditions.”
The research includes support by a team of scientists at Rothamsted Research, led by professor Matthew Paul, to understand the regulation of plant and crop processes by T6P. This biological knowledge will help Syngenta develop crop traits for the world’s farmers.
T6P drives the allocation of the plant’s main sugar, called sucrose, to different parts of the plant during growth and development. By altering the amounts of T6P in key cells that deliver sucrose to developing seeds in the cobs, more sucrose is transported into the corn kernels. This increases seed numbers per cob and the overall harvest index and yield.
“The work shows that T6P exerts significant control of yield in corn,” Paul says. “This is one of few reports where genetic modification of an intrinsic plant process for yield works in the field.
“We think that this can be explained because there is a tension between the need to produce enough seed to survive against the need to adjust seed number to ensure viability. It is possible that natural selection has placed greater emphasis on survival of a few viable seed rather than on maximizing seed numbers and productivity per se, as required in an agricultural system and there is still room to select for this.”
The scientists consider the corn yield increases could be the tip of the iceberg.
“Corn is the world’s highest yielding crop,” Paul says. “This technology has the potential to greatly improve maize productivity. Imagine what could be achieved for global food security if this trait were targeted in other crops, too. Not only does it increase maximum yield output, but it also prevents catastrophic yield loss in dry years.”