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
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering