The new method is described this week in the journal Science.
The team includes scientists from Cornell University, the University of Illinois, Boyce Thompson Institute, DuPont Crop Genetics Research, the University of North Carolina, the City University of New York, the International Maize and Wheat Improvement Center and the U.S. Department of Agriculture.
The innovation involves a new approach for selecting the parent stock for breeding maize, and significantly reduces the ambiguity and expense of finding varieties that yield the highest provitamin A content available. As part of this investigation, the researchers have identified a naturally mutated enzyme that enhances the provitamin A content of maize.
Vitamin A deficiency is a leading cause of eye disease and other health disorders in the developing world. Some 40 million children are afflicted with eye disease, and another 250 million suffer with health problems resulting from a lack of dietary vitamin A.
“Maize is the dominant subsistence crop in much of Sub-Saharan Africa and the Americas,” the researchers write, “where between 17 and 30 percent of children under the age of 5 are vitamin A deficient.”
Maize also is one of the most genetically diverse food crops on the planet, said Torbert Rocheford, a professor of nutritional sciences at Illinois and a corresponding author on the paper.
This diversity is tantalizing to those hoping to make use of desirable traits, but it also provides a formidable challenge in trying to understand the genetic basis of those attributes.
One hurdle to increasing the provitamin A content of maize has been the expense of screening the parent stock and progeny of breeding experiments, Rocheford said.
A common technique, called high performance liquid chromatography (HPLC), can assess the provitamin A content of individual plant lines. But screening a single sample costs $50 to $75, he said.
“That’s really expensive, especially since plant breeders like to screen hundreds or more plants per cycle, twice a year,” he said. “The cost was just prohibitive.”
The new approach uses much more affordable methods and gives a more detailed picture of the genetic endowment of individual lines. One technique the researchers employed, called quantitative trait loci (QTL) mapping, allowed them to identify regions of the maize chromosomes that influence production of the precursors of vitamin A. They also used association mapping, which involves studying variation in selected genes and tracking inheritance patterns to see which form of a gene coincides with the highest provitamin A content. Polymerase chain reaction (PCR) allowed them to amplify and sequence the different versions (alleles) of the genes of interest, to find the alleles that boosted levels of vitamin A precursors in the plant.
This approach led to an important discovery. The team found a mutant form of an enzyme vital to the cascade of chemical reactions that produce the precursors of vitamin A in the plant. This mutant is transcribed in lower quantities than the normal allele and steers the biochemistry toward producing higher levels of vitamin A precursors.The study analyzed 300 genetic lines selected to represent the global diversity of maize, and identified some varieties that came close to the target amount of 15 micrograms of beta-carotene (a form of provitamin A) per gram. Current maize varieties consumed in Africa can have provitamin A content as low as 0.1 micrograms per gram.
Diana Yates | University of Illinois
Small but versatile; key players in the marine nitrogen cycle can utilize cyanate and urea
10.12.2018 | Max-Planck-Institut für Marine Mikrobiologie
Carnegie Mellon researchers probe hydrogen bonds using new technique
10.12.2018 | Carnegie Mellon University
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
10.12.2018 | Event News
06.12.2018 | Event News
03.12.2018 | Event News
10.12.2018 | Life Sciences
10.12.2018 | Physics and Astronomy
10.12.2018 | Life Sciences