Individuals of one and the same plant species often differ greatly in their ability to resist pathogens: While one rose succumbs to bacterial infection, its neighbor blissfully thrives. Scientists from the Max Planck Institute of Developmental Biology in Germany have tracked down an explanation for this common phenomenon.
Their conclusion: disease resistance can incur high costs. Especially resistant plants of mouse ear cress (Arabidopsis thaliana) produce fewer and small leaves, and have a competitive disadvantage in the absence of enemies. Whether it is better to invest into disease resistance or biomass is thus very much dependent on the unpredictable circumstances a plant may find itself in. Therefore both large, but vulnerable plants co-exist in nature with small, but well-protected ones (Nature, June 3, 2010).
In the course of evolution, plants invented many ways to defend themselves against enemies. Some produce smelly or bad-tasting ingredients, others develop thorns or have a particular effective immune response to viruses and bacteria. If selection pressure is sufficiently high, one would thus expect only those individuals to survive that are best protected. Pathogens, in turn, should have a difficult time. Everybody knows that this is not the case. Indeed, plants vary tremendously in their ability to defend themselves, and this is true not only for different species, but also for members of the same species.
The group of Detlef Weigel at the Max Planck Institute for Developmental Biology has now tracked down a variant of the ACD6 gene, which functions as a universal weapon in the fight against predators. With it, the plants both produce much more of a chemical that is directly toxic to microbes and more signaling molecules important in immunity. These enable mouse ear cress plants to combat a wide range of enemies, from bacteria and fungi to insects such as aphids. However, not all varieties have this variant. While it occurs throughout the area where mouse ear cress grows, from North Africa to Scandinavia, and from Central Asia to Western Europe, at any given place it is found in only about 20 percent of individuals. This already suggests that this variant might also confer some disadvantages.
“We could show that this gene makes plants resistant against pathogens, but at the same time it slows down the production of leaves and limits the size of leaves, so that these plants are always smaller than those that do not have this variant,” said Detlef Weigel. “But as soon as they are being attacked, the plants with the special ACD6 variant have a leg up compared to plants with the standard version. On the down side, at places or in years where there are few enemies, they are penalized and lose out compared to the larger fellow plants.” Smaller size eventually leads to reduced number of seeds and hence to fewer progeny. The conclusion of Weigel: “Just as in human society, there is no free lunch in nature.”Scientists and institutes that participated in this study
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News