Hemoglobins, key components of our blood, are ancient proteins with well-known roles in oxygen transport and respiration in animals. Hemoglobins are also present in plants and bacteria, but until now the physiological role of plant hemoglobins has been unclear. A group of researchers reveal this week that one such mysterious plant hemoglobin serves to assist in the fixation of nitrogen in the root nodules of legumes through a process that is conceptually not unlike that undertaken by mammalian hemoglobins in facilitating oxygen transport and exchange in the blood.
The most conspicuous plant hemoglobins are the symbiotic hemoglobins of legumes; these hemoglobins accumulate in root nodules and give these specialized organs their distinctive red color. Legume root nodules accommodate bacteria, called rhizobia, that reduce atmospheric nitrogen to ammonia, which is subsequently used by the plant for growth and colonization of nitrogen-poor soils. Symbiotic nitrogen fixation is important for sustainable agriculture and contributes millions of tons of reduced nitrogen to crops and pastures each year.
As reported this week, researchers led by Dr. Michael Udvardi at the Max Planck Institute of Molecular Plant Physiology have succeeded in eliminating the production of symbiotic hemoglobins in nodules of the model legume Lotus japonicus, enabling researchers to assess for the first time the role and importance of these proteins in plants. The results of the study indicate that symbiotic hemoglobins are important for oxygen transport and energy metabolism in plant root nodules. Furthermore, these proteins help to maintain free-oxygen concentrations in nodules at levels low enough to avoid damage of oxygen-sensitive nitrogenase, the bacterial enzyme complex responsible for symbiotic nitrogen fixation. Thus, plant hemoglobins fulfill roles analogous to those of animal hemoglobins, as well as novel roles that are apparently unique to symbiotic nitrogen fixation.
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Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
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In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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