Targeted increase of sugar improves yields of drought-affected corn

A collaborative project between Syngenta and Rothamsted Research has shown that genetically altering the amount of a naturally occurring sugar improves the yield of drought-affected corn.

The research was published in the journal of Nature Biotechnology.

Drought impacts crops worldwide, hitting poorest farmers most dramatically. In the U.S. and even in the U.K., predictions remain that water will become limited for crops. The world’s major crops -- corn, rice and wheat -- have been affected by drought during the flowering period.

Syngenta scientists introduced a single transgene to alter the amount of a naturally occurring sugar called trehalose 6-phosphate, or T6P. The plants were evaluated over several years in extensive maize field trials in North and South America.

Through this transgene, 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.

The research includes support by scientists at Rothamsted Research led by 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. This is one of few reports where genetic modification of an intrinsic plant process for yield works in the field," Professor Matthew Paul said. "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."

“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. This knowledge will be important for designing the next generation of crop varieties able to remain productive under water-limiting conditions,” Michael Nuccio, principal research scientist at Syngenta and the study leader, said.

There could be further success if this trait could be targeted in other crops. Not only does it increase maximum yield output, but it also prevents catastrophic yield loss in dry years.