Scientists assumed leaves at the top of a plant would be the best at turning higher levels of light into carbohydrates--through the process of photosynthesis -- while the lower shaded leaves would be better at processing the low light levels that penetrate the plant's canopy of leaves. Turns out that in two of our most productive crops, these shaded leaves are less efficient than the top leaves, limiting yield.
These findings, published in the Journal of Experimental Botany, could help scientists further boost the yields of corn and Miscanthus, as well as other C4 crops that have evolved to photosynthesize more efficiently than C3 plants such as¬ wheat and rice.
"The wild ancestors of C4 crops are thought to have grown as individuals in open habitats where the number of leaves that they produced would have been limited by water and nitrogen and most leaves would be exposed to full sunlight" said principal investigator Steve Long, Gutgsell Endowed Professor of Plant Biology and Crop Sciences at the University of Illinois.
"Today we grow these crops in ever denser stands, and provide them with nitrogen and water so that they can produce many more layers of leaves. But as a result, the proportion of leaves that are shaded has increased, and the production of grain will depend more and more on the contribution of this increasing proportion of shaded leaves. So how do the Maseratis of photosynthesis, C4 crops, do when they are on a meager meager fuel ration in the shade?"
Not well, according to this paper: when top and bottom leaves are placed in the same low light, the lower canopy leaves showed lower rates of photosynthesis. Shaded corn leaves are 15 percent less efficient than top leaves--and worse, lower leaves are 30 percent less efficient than the top leaves of Miscanthus, a perennial bioenergy crop that is 60 percent more productive than corn in Illinois.
Considering the crop as a whole, this loss of efficiency in lower leaves may costs farmers about 10 percent of potential yield--a cost that will increase as planting density increases. This 'Achilles' heel' likely applies to other C4 relatives, such as sugarcane and sorghum.
"What's interesting is that we saw this loss in efficiency in the lower canopy was not due to the leaf senescing and dying off--we would have expected that," said first author Charles Pignon, a doctoral candidate in the crop sciences and at the Carl R. Woese Institute for Genomic Biology. "The leaves were still perfectly healthy when we were looking at them; they were even darker. In the article, we show through experiments that this was not caused by age."
"Next, it will be important to find out why this loss in efficiency occurs and if there's any way that we can fix it, since overcoming this and gaining a 10 percent increase in production would be very significant," Pignon said.
The paper "Loss of photosynthetic efficiency in the shade. An Achilles heel for the dense modern stands of our most productive C4 crops" was published in Journal of Experimental Botany . Co-authors also include Deepak Jaiswal and Justin McGrath, a postdoctoral researcher at the University of Illinois.
This work was supported by the Energy Biosciences Institute (EBI). The EBI is a public-private collaboration supported from BP in which bioscience and biological techniques are applied to help solve the global energy challenge. For more information, visit http://www.
Claire Benjamin | EurekAlert!
Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Filling intercropping info gap
16.11.2017 | American Society of Agronomy
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
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...
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...
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....
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,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences