Ion transporters in chloroplasts affect the efficacy of photosynthesis
2021-05-14
(Press-News.org) A study led by LMU plant biologist Hans-Henning Kunz uncovers a new role for ion transporters: they participate in gene regulation in chloroplasts.
In plants, photosynthesis takes place in intracellular 'factories' called chloroplasts. Plant chloroplasts evolved from photosynthetic cyanobacteria, which were engulfed by a non-photosynthetic cell in the course of evolution. As a result of this evolutionary event, chloroplasts possess two envelope membranes, and have retained functional remnants of their original cyanobacterial genomes. Henning Kunz (LMU Biocenter), his group, and their collaborators have now demonstrated that proteins involved in ion transport in the inner chloroplast membrane participate in the regulation of gene expression in the organelle, therefore playing an important role in the control of photosynthesis.
Photosynthesis actually occurs in a highly specialized 'thylakoid' membrane system in the chloroplast. This system is encapsulated by the inner and outer envelope. Among the proteins embedded in the inner membrane are ion transporters that regulate the ion balance in the medium, known as the stroma, which bathes the thylakoid membranes in the center of the organelle. It also contains the organelle's DNA genome, and the ribosomes that synthesize the proteins which it encodes. Notably, photosynthesis is crucially dependent on the coordinated expression of the chloroplast genome and genes that now reside in the cell nucleus. "Using the model plant Arabidopsis thaliana, we have now shown that the ion balance in the stroma plays a role in the exchange of regulatory information between chloroplasts and the nucleus," says Kunz.
He had previously observed that chloroplast development was delayed and plant growth retarded when two genes that code for specific ion-transport proteins were deleted. "Our experiments show that, in the absence of these ion transporters, certain RNA binding proteins that are encoded by nuclear genes are unable to bind to their target RNAs in the stroma of the chloroplasts," he explains. As a consequence, the processing and maturation of these RNAs (which are necessary for the transfer of genetic information from the chloroplast genome into stromal proteins) is inhibited. "This defect has a particularly significant effect on RNAs that are required for ribosome assembly in the stroma. The resulting reduction in the numbers of functional ribosomes severely impairs chloroplast protein synthesis in these mutants," Kunz explains.
The results reported in the new study could contribute to efforts to enhance the efficiency of photosynthesis under otherwise unfavorable environmental conditions, which would help crop plants to adapt to climate change. "Ion transporters could serve as important tools in this context," says Kunz. "Photosynthetic efficiency is highly dependent on the biochemistry of the stroma. These transport proteins have an important influence on this fine-tuned balance. Only if we start to understand their structures and complex functions in detail it will be possible to manipulate and benefit from the transporters' action."
INFORMATION:
ELSE PRESS RELEASES FROM THIS DATE:
2021-05-14
Input one, output one; input two, output two; input three; output purple --what kind of system is this? Computer algorithms can exist as non-deterministic systems, in which there are multiple possible outcomes for each input. Even if one output is more likely than another, it doesn't necessarily eliminate the possibility of putting in three and getting purple instead of three. Now, a research team from Iowa State University has developed a way to control such systems with more predictability. The results were published in IEEE/CAA Journal of Automatica Sinica.
"The supervisory control problem for discrete event systems under control involves ...
2021-05-14
The ability to visualize transparent objects such as biological cells is of fundamental importance in biology and medical diagnostics. Conventional approaches to achieve this include phase-contrast microscopy and techniques that rely on chemical staining of biological cells. These techniques, however, rely on expensive and bulky optical components or require changing, and in some cases damaging, the cell by introducing chemical contrast agents. Significant recent advances in nanofabrication technology permit structuring materials on the nanoscale with unprecedented ...
2021-05-14
Australian researchers have documented the diversity of cells in the human breast, explaining the relationship between healthy breast cells and breast cancer cells.
The research, which relied on expertise spanning from breast cancer biology through to bioinformatics, measured gene expression in single cells taken from healthy women and cancerous breast tissue, including tissue carrying a faulty BRCA1 gene. This enabled the researchers to create an 'RNA atlas' that details the different cells found in these tissues.
The atlas, which was described in EMBO Journal, ...
2021-05-14
Japanese researchers successfully tested reflectionless, highly refractive index metasurface that may eventually be used in practical applications to send, receive, and manipulate light and radio waves in the terahertz waveband (THz). THz is measured in millionths of a meter, known as micrometers. The metasurface, an artificial two-dimensional flat material, was made of micro-sized cut metal wires of silver paste ink placed on both the front and back of a polyimide film. The team, led by Takehito Suzuki, Associate Professor at the Tokyo University of Agriculture and Technology (TUAT) Institute of Engineering, published their findings on April 29, 2021 in Optics Express.
Such flat metasurfaces ...
2021-05-14
Psychology researchers at UC Santa Cruz have found that playing games in virtual reality creates an effect called "time compression," where time goes by faster than you think. Grayson Mullen, who was a cognitive science undergraduate at the time, worked with Psychology Professor Nicolas Davidenko to design an experiment that tested how virtual reality's effects on a game player's sense of time differ from those of conventional monitors. The results are now published in the journal Timing & Time Perception.
Mullen designed a maze game that could be played in both virtual reality and conventional formats, then the research team recruited 41 UC Santa Cruz undergraduate ...
2021-05-14
The COVID-19 pandemic has been shown to have caused a significant strain on the healthcare system and resources in the United States. However, data regarding the impact of the virus on hip fractures, primarily seen in elderly patients, is lacking.
Researchers at Hospital for Special Surgery (HSS) sought to compare characteristics and outcomes of hip fracture patients admitted during the COVID-19 outbreak to patients admitted before the outbreak. They also examined characteristics and outcomes of hip fracture patients with and without the virus. Their findings were presented at the 2021 Spring American Society of Regional Anesthesia and ...
2021-05-14
Interim results of a study conducted by researchers at Hospital for Special Surgery (HSS) suggest that oral tranexamic acid (TXA) is non-inferior to intravenous (IV) TXA in preventing blood loss in total knee and total hip replacement surgery. These findings were presented at the 2021 Spring American Society of Regional Anesthesia and Pain Medicine (ASRA) Annual Meeting.1
Previously available information suggests that oral, IV and topical TXA are all effective at reducing blood loss and drastically reducing blood transfusion rates during and after surgery, but research with direct comparisons for each method is limited.
"TXA in orthopedic surgery has become the standard ...
2021-05-14
While it has been said that the eyes are a window to the soul, a new study shows they could be a means for understanding diseases of the brain. According to new research by scientists at the UCSF Weill Institute for Neurosciences, retinal scans can detect key changes in blood vessels that may provide an early sign of Alzheimer's, while offering important insights into how one of the most common Alzheimer's risk genes contributes to the disease.
"The most prevalent genetic risk for Alzheimer's disease is a variant of the APOE gene, known as APOE4," said lead author Fanny Elahi, MD, PhD. "We still don't fully understand how this variant increases risk of brain degeneration, we just know that it does, and that this risk is modified by sex, race, and lifestyle. "Our ...
2021-05-14
Climate change is exacerbating problems like habitat loss and temperatures swings that have already pushed many animal species to the brink. But can scientists predict which animals will be able to adapt and survive? Using genome sequencing, researchers from McGill University show that some fish, like the threespine stickleback, can adapt very rapidly to extreme seasonal changes. Their findings could help scientists forecast the evolutionary future of these populations.
A popular subject of study among evolutionary ecologists, stickleback are known for their different shapes, sizes, and behaviours - they can even live in both seawater and freshwater, and under a wide range of temperatures. But what ...
2021-05-14
Plants have evolved unique immunity mechanisms that they can activate upon detecting the presence of a pathogen. Interestingly, the presence of some nonpathogenic microorganisms can also prompt a plant to activate its systemic immunity mechanisms, and some studies have shown that pretreating agricultural crops with such "immunity-activating" nonpathogenic microorganisms can leave the crops better prepared to fight off infections from pathogenic microorganisms. In effect, this means that immunity-activating nonpathogenic microorganisms can function like vaccines for plants, providing a low-risk stimulus for the plant's immune system that prepares it for dealing with genuine threats. These are exciting findings for crop scientists because they suggest the ...
LAST 30 PRESS RELEASES:
[Press-News.org] Ion transporters in chloroplasts affect the efficacy of photosynthesis
