Thiol Redox Switches in Germination – New Insights on Seed Germination
Plants are normally considered unspectacular by a casual observer but plants indeed have fascinating properties nothing short of superpowers. In a dry state, plants are capable of storing their energy for years and can release the energy to germinate anytime. The striking example for this scenario is the “super bloom” in the Death Valley National Park as the seeds suddenly germinate at rainfall and continue to have a spectacular desert bloom for several months after enduring the dry and hot desert for decades. A fully formed embryo is conserved in the plant seeds and when there are appropriate conditions, it continues to grow. This growth can happen even centuries later or in a few years. Intense research has been done on several plant hormones that control seed germination.
There have been many questions in this regard as to how is the energy in the seeds is made available, how can energy metabolism started efficiently and early and now a team of international scientists has discovered that in kick-starting the energy metabolism, the thiol redox switches play a key role.
The scientists observed in living seed cells, the energy metabolism
and the redox metabolism both of which relied on sulfur, using a new type of fluorescent biosensors. It was discovered that the energy metabolism was established in a matter of minutes when the seeds came into contact with water and their respiration is activated by the mitochondria or the plant cells’ “power stations”. Scientists also found out that to enable energy to be released efficiently, which molecular switched are activated and hence unraveled the central role played by thiol-redox switches.The lead of the study, Prof. Markus Schwarzländer from the University of Münster (Germany) says, ” We can get a better understanding of the mechanisms driving seed germination by looking into the very early processes of germination control. The uses of such switches could be applied in crop biotechnology in the future.” In farming, this study’s results could be useful as it can be known how seeds can germinate in synch and with minimal losses and also, on the other hand, it can be known how to have seeds to keep their germination vigor for as long as possible.
Method and Background
The general currency for energy in the cell, adenosine triphosphate (ATP) and the electron energy, Nicotinamide adenine dinucleotide phosphate (NADPH) in the mitochondria were visualized under the microscope by the researchers to be able to observe the activities taking place in the energy metabolism. They compared seeds from thale cress: both seeds “imbibed” with water and dry seeds.
Scientists first deactivated specific proteins using genetic methods and then compared the reaction shown by the modified seeds with that of the unmodified ones to find out whether the redox switches are important for kick-starting germination or not. It was seen that if the seeds lacked the relevant proteins, the seeds germinated much less active when they were allowed to age artificially in the laboratory.
By using biochemical methods, the researched then performed the so-called redox proteome analysis where they examined the relevant redox proteins in their entirety. The active mitochondria were isolated for this purpose and it was flash-frozen for studying this state directly where the process was taking place. Several so-called cysteine-peptides that are important for resource efficiency in energy metabolism were identified using mass spectrometry methods.
The lead author of the study, who carried out most of the experiments as part of his Ph.D. at the Institute of Crop Science and Resource Conservation at the University of Bonn and later as a postdoctoral researcher at the Institute of Biology and Biotechnology of Plants at the University of Münster, Dr. Thomas Nietzel explained that ” The traffic control system of a large city can be linked to this process. The germination or before the rush hour starts, putting a huge amount of metabolites ‘on the road, in the morning, the traffic light and routing systems need to be switched on.
Proceedings of the National Academy of Sciences(PNAS) journal published this study.
SOURCE-Thiol Redox Switches in Germination, Thiol Redox Switches in Germination
Good findings