Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stronger corn? Take it off steroids, make it all female

01.12.2011
A Purdue University researcher has taken corn off steroids and found that the results might lead to improvements in that and other crops.

Burkhard Schulz, an assistant professor of horticulture and landscape architecture, wanted to understand the relationship between natural brassinosteroids - a natural plant steroid hormone - and plant architecture, specifically plant height. Schulz said corn could benefit by becoming shorter and sturdier, but the mechanisms that control those traits are not completely understood.

"It is essential to change the architecture of plants to minimize how much land we need to produce food and fuels," said Schulz, whose findings are published in the early online version of the Proceedings of the National Academy of Sciences. "If you can find a natural mutation or mechanism that gives you what you need, you are much better off than using transgenic techniques that could be difficult to get approval for."

Schulz found that when maize loses the ability to produce brassinosteroids, it becomes a dwarf, as he suspected. But another feature caught him off guard: The plants without the naturally occurring steroids could not make male organs - they had kernels where the tassels should be.

That could be a cost-saving discovery for the seed industry. Hybrid seed producers must painstakingly remove the male pollen-producing tassels from each plant so that they do not pollinate themselves. Schulz said maize plants that produce only female organs would eliminate the detasseling step.

"This would be the perfect mutation for hybrid seed production," Schulz said. "There is no way these plants could produce pollen because they do not have male flowers."

Schulz used a multistep process to determine brassinosteroids' role in height and, later, sex determination. He wanted to ensure that light and the addition of gibberelic acid, a hormone that promotes cell growth and elongation, would not eliminate the dwarfism.

Schulz gathered known mutants of maize with short mesocotyls, the first node on a corn stalk. He suspected that even dwarf plants that produced brassinosteroids would have elongated mesocotyls if grown in the dark as they stretched for light, a trait typical of all brassinosteroid mutants. He also added gibberellic acid to the plants to ensure that a deficiency of that hormone was not causing the dwarfism.

The dwarf plants that did not grow in the dark or with the addition of the gibberellic acid were compared to regular maize plants that had been dwarfed by subjecting them to a chemical that disrupts the creation of brassinosteroids. Both exhibited short stalks with twisted leaves and showed the feminization of the male tassel flower.

Schulz then used information that was already known from the research plant Arabidopsis about genes that control brassinosteroid production. He found the same genes in the maize genome.

In the dwarf maize plants, those genes were mutated, disrupting the biosynthesis of the steroids. A chemical analysis showed that the compounds produced along the pathway of gene to steroid were greatly diminished in the maize dwarfs. Cloning of the gene revealed that an enzyme of the brassinosteroid pathway was defective in the mutant plants. A related enzyme in humans has been reported as essential for the production of the sex steroid hormone testosterone. Mutations in this enzyme in humans also resulted in feminization.

While Schulz expected brassinosteroids to affect plant height, he said he did not expect those steroids to affect sex determination.

"We don't know if this is a special case for corn or if this is generally the same in other plants," he said. "If it is the same in other plants, it should be useful for creating plants or trees in which you want only males or females."

Gurmukh Johal, a professor of botany and plant pathology and collaborator on the research, identified the mutant used in the research, nana plant1, years ago. He said better understanding the steroid-production pathways could be important to strengthening maize plants and increasing yields.

"Maize produces too much pollen and it actually wastes a lot of energy on that," Johal said. "This implies that by using this gene or the pathway it controls, we could manipulate the plants to improve their quality."

Schulz said he would look at other plants, such as sorghum, to determine if the same genes and pathways control sex determination and height.

The project was an international collaboration with George Chuck from the Plant Gene Expression Center at the University of California Berkeley, Shozo Fujioka of RIKEN Advanced Science Institute in Japan, Sunghwa Choe of Seoul National University in South Korea, and Devi Prasad Potluri of Chicago State University.

The National Science Foundation and the U.S. Department of Agriculture funded the research.

Writer: Brian Wallheimer, 765-496-2050, bwallhei@purdue.edu

Sources: Burkhard Schulz, 765-496-3635, bschulz@purdue.edu
Gurmukh Johal, 765-494-4448, gjohal@purdue.edu

Brian Wallheimer | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Agricultural and Forestry Science:

nachricht Filling intercropping info gap
16.11.2017 | American Society of Agronomy

nachricht Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>