If corn's intolerance of low temperatures could be overcome, then the length of the growing season, and yield, could be increased at present sites of cultivation and its range extended into colder regions.
Drs. Dafu Wang, Archie Portis, Steve Moose, and Steve Long in the Department of Crop Sciences and the Institute of Genomic Biology at the University of Illinois may have made a breakthrough on this front, as reported in the September issue of the journal Plant Physiology.
Plants can be divided into two groups based on their strategy for harvesting light energy: C4 and C3. The C4 groups include many of the most agriculturally productive plants known, such as corn, sorghum, and sugar cane. All other major crops, including wheat and rice, are C3. C4 plants differ from C3 by the addition of four extra chemical steps, making these plants more efficient in converting sunlight energy into plant matter.
Until recently, the higher productivity achieved by C4 species was thought to be possible only in warm environments. So while wheat, a C3 plant, may be grown into northern Sweden and Alberta, the C4 grain corn cannot. Even within the Corn Belt and despite record yields, corn cannot be planted much before early May and as such is unable to utilize the high sunlight of spring.
Recently a wild C4 grass related to corn, Miscanthus x giganteus, has been found to be exceptionally productive in cold climates. The Illinois researchers set about trying to discover the basis of this difference, focusing on the four extra chemical reactions that separate C4 from C3 plants.
Each of these reactions is catalyzed by a protein or enzyme. The enzyme for one of these steps, Pyruvate Phosphate Dikinase, or PPDK for short, is made up of two parts. At low temperature these parts have been observed to fall apart, differing from the other three C4 specific enzymes. The researchers examined the DNA sequence of the gene coding for this enzyme in both plants, but could find no difference, nor could they see any difference in the behavior of the enzyme in the test tube. However, they noticed that when leaves of corn were placed in the cold, PPDK slowly disappeared in parallel with the decline in the ability of the leaf to take up carbon dioxide in photosynthesis. When Miscanthus leaves were placed in the cold, they made more PPDK and as they did so, the leaf became able to maintain photosynthesis in the cold conditions. Why?
The researchers cloned the gene for PPDK from both corn and Miscanthus into a bacterium, enabling the isolation of large quantities of this enzyme. The researchers discovered that as the enzyme was concentrated, it became resistant to the cold, thus the difference between the two plants was not the structure of the protein components but rather the amount of protein present.
The findings suggest that modifying corn to synthesize more PPDK during cold weather could allow corn, like Miscanthus, to be cultivated in colder climates and be productive for more months of the year in its current locations. The same approach might even be used with sugar cane, which may be crossed with Miscanthus, making improvement of cold-tolerance by breeding a possibility.
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At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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