Talk about genetically modifying wheat for the sake of science, actually to develop a ‘TILLING’ resource for wheat: Recently, scientists from the University of California, Davis, have discovered the function of a gene that allows wheat to discern the length of each day and night, according to the new report finding. When UC Davis researchers knocked out the gene, wheat flowering was delayed for more than 100 days. The finding, “PHYTOCHROME C plays a major role in the acceleration of wheat flowering under long-day photoperiod,” published online June 24, 2014 in the journal Proceedings of the National Academy of Sciences, gives plant breeders and researchers a new tool for either accelerating or delaying wheat’s flowering time, which is important for adapting the crop to new and changing climates. TILLING is an abbreviation for targeting induced local lesions in genomes. It’s not about weeding a garden as in ’tilling’ the soil.
TIILLING allows the researchers to make almost any gene inoperative. In this new study, the scientists were able to knock out the different copies of the plant’s gene, known as Phytochrome C, in order to study their function.
Though plants don’t have the sensory organs to actually see light, they have developed biochemical responses for detecting when it is springtime. Proteins called phytochromes are activated by red light and regulate the responses of many other genes
The University of California, Davis researchers found that the gene — named Phytochrome C — changes form when it detects the red hues of daylight and activates a separate gene, known as Photoperiod 1. This gene is also regulated by the circadian clock that oscillates with every 24-hour period. The simultaneous regulation of Photoperiod 1 by light signal (an external signal) and by the circadian clock (an internal oscillator) is required to measure the length of days and nights.
The discovery of the Phytochrome C function was made possible by a genetic technique called “TILLING,” or Targeting Induced Local Lesions IN Genomes. The process was developed by UC Davis plant biology professor Luca Comai and adapted to wheat by UC Davis plant sciences professor Jorge Dubcovsky, a wheat geneticist and senior author on the new paper.
“We’ve invested a lot of our time in recent years to develop a TILLING resource for wheat,” Dubcovsky said, according to a June 23, 2014 UC Davis news release, Springtime for wheat starts with a gene that ‘sees’ light. “That has enabled us to do studies in wheat that we were not able to do in the past. We couldn’t answer those questions before.”
While breeders are already able to modify flowering time in wheat, this discovery provides one more way of doing that
The scientists will now start looking for variations in Phytochrome C that can be used to alter the flowering time in wheat. This would allow breeders to adapt wheat to new geographic climates and would mean farmers in northern regions could better manage their shorter growing seasons.
“We’ve gone one step deeper in our basic understanding of wheat flowering,” Dubcovsky said, according to the news release.
The loss of functional wheat PHYC results in altered expression of circadian clock and photoperiod genes and a dramatic delay in flowering under long days, indicating that PHYC promotes wheat flowering under inductive photoperiods, explains the study’s abstract. The findings of the study provide another entry point to modify wheat flowering and to accelerate the development of wheat varieties better adapted to new and changing environments.
Other UC Davis researchers on this study included Andrew Chen, Chengxia Li, Wei Hu, Mei Yee Lau, Huiqiong Lin, Nathan C. Rockwell, Shelley S. Martin, Judith A. Jernstedt and J. Clark Lagarias. More information about TILLING is available at the UC Davis TILLING website.
Wheat geneticist Jorge Dubcovsky has been named a recipient of the 2014 Wolf Prize in Agriculture, recognizing his work in improving the world’s most important source of food grain for people
The Jerusalem-based Wolf Foundation named two Wolf Prize winners in agriulcture this year, the other being Leif Andersson of Uppsala University, Sweden, according to another UC Davis news release from January 20, 2014, “Jorge Dubcovksy wins Wolf Prize for improvements to wheat.” The $100,000 Wolf Prizes are awarded annually to outstanding scientists and artists in the fields of agriculture, chemistry, physics, mathematics, medicine and the arts. This year five prizes were awarded to eight individuals in four countries.
The new Wolf Prize laureates received their awards in May 2014 from the president of Israel and Israel’s minister of education during a ceremony at the Knesset Building in Jerusalem. In selecting Dubcovsky, the Wolf Foundation committee wrote that his research achievements are “truly impressive” and that Dubcovsky’s “combined basic and applied approach was able to dramatically improve the nutritional value of wheat, and the impact of the discoveries was increased when they were made available to the scientific community.”
Dubcovsky, a professor in the Department of Plant Sciences and a Howard Hughes Medical Institute and Gordon and Betty Moore Foundation investigator, was born and raised in Argentina. He began his career teaching middle school science and math classes, and earned his bachelor’s degree in biological sciences from the University of Buenos Aires in 1984.
He received his doctoral degree in biological sciences in 1989 from the University of Buenos Aires. In 1992, interested in the techniques that were becoming available in the growing field of molecular biology, he came to UC Davis for a research fellowship under the direction of Professor Jan Dvorak. Employing such techniques, he and Dvorak used molecular markers to mine new information about plant biology and generated the first molecular genetics maps in wheat.
Dubcovsky joined the University of California, Davis faculty in 1996. During the past two decades, he has conducted pioneering research in mapping and isolating genes in wheat’s massive genome and deploying those genes in wheat cultivars. He and his laboratory colleagues have identified and cloned genes involved in disease resistance, protein content, flowering and frost tolerance. Identification of these important genes has enabled researchers and breeders to accelerate the development of more nutritious and better-adapted wheat varieties.
In 2011, Dubcovsky received a USDA Honor Award, the most prestigious award given by the agency’s secretary in recognition of exceptional leadership in science, public policy and management vital to guiding the nation’s food and agricultural system. In 2013, he was elected to the National Academy of Sciences, one of the highest honors for scientists and engineers in the United States.
German-born inventor, diplomat and philanthropist Ricardo Wolf established the Wolf Foundation in 1975 A resident of Cuba for many years, he became Fidel Castro’s ambassador to Israel, where he lived until his death in 1981. Five or six annual Wolf Prizes have been awarded since 1978 to outstanding scientists and artists. A total of 290 individuals from around the world, including this year’s laureates, have been honored with this prestigious prize.