Engineered wheat thwarts pre-harvest sprouting

May 12, 2009
Scientists from opposite sides of the world have created an improved variety of wheat by discovering how to prevent the phenomenon of premature sprouting, which can wipe out an entire crop.

The researchers, based at UC Berkeley and in Zhengzhou, China, have found a way to control “pre-harvest sprouting”–a situation in which wheat seeds sprout before they are harvested. This international problem destroys about 20 percent of all wheat in China annually. By overcoming this problem, the researchers expect to dramatically increase wheat yields and reduce the cost of products such as wheat noodles, a staple of the Chinese diet. The same procedure could be applied to barley, increasing yields for grain used in malting for beer.
This international collaboration has special significance to UC Berkeley researchers Bob Buchanan and Peggy Lemaux. These plant biologists have devoted their careers to improving crops, with several important breakthroughs in engineered cereal crops to their credit, including the development of hypoallergenic wheat and helping improve the nutritional quality of sorghum, a major food in developing countries. Most of the potential commercial and humanitarian applications of these findings have gone unrealized due to western resistance to GMOs. However, Buchanan and Lemaux expect the work on pre-harvest sprouting to result in commercialized wheat varieties in China.

The researchers in the current study, led by Jun Yin, a wheat specialist at Henan Agricultural University in Zhengzhou, found that reduced production of a central regulatory protein of seeds, thioredoxin h (Trx h), led to a dramatic decrease in the incidence of pre-harvest sprouting. The study builds on Buchanan’s work and stems from experiments he started in Berkeley as a postdoctoral researcher in 1962. Buchanan’s research on the role of Trx in seeds became well known in China beginning about 15 years ago, culminating with his visit to Zhengzhou in 2007, which solidified the international group’s current collaboration.

The research efforts of the two groups are described in an article appearing in a special issue of Molecular Plant, a peer-reviewed journal founded by UC Berkeley plant biologist Sheng Luan, and published on behalf of the Chinese Academy of Sciences (Molecular Plant 2009 3:430-441). The journal underscores China’s growing prominence in biology, especially the plant sciences, and sets an ongoing trend to establish a number of premier international journals. These developments are the result of the more than 40-fold increase in research funds, much of it for plant biology, made available in China in the past two decades.