A study on the mechanisms of how plants respond and adapt to elevated levels of carbon dioxide (C02) and higher temperatures has opened a new perspective in climate research. Lead researcher Qiong A. Liu (Alison) of the Department of Biochemistry and Cell Biology at Stony Brook University found that elevated C02 and higher temperatures affect the aspect of gene expression in plants that control flowering time and cell proliferation.
The results of the study, “The Effects of Carbon Dioxide and Temperature on microRNA Expression in Arabidopsis Development,” are published July 31 in the online journal Nature Communications.
Elevated C02 levels in the atmosphere have enhanced the greenhouse effect and resulted in climate change — and continued climate change within this century is inevitable. But how do these changes impact plants on a cellular level? To discover the answer, Liu focused on examining the impact that increased levels of C02 and increased temperature, each separately had on small RNAs in Arabidopsis thaliana, small flowering plants that only need about six weeks to go from germination to seed maturation.
Small RNAs are important regulators of gene expression in nearly all eukaryotes —organisms whose cells contain a nucleus and other structures within membranes. Their expressions can be altered in response to environmental stress. MicroRNAs (or miRNAs) belong to one of two types of small RNAs that function to silence the expression of their regulated target genes. Therefore, increased levels of miRNAs can reduce their target gene expression, and vice versa. Since miRNA target genes are often important regulators in specific biological pathways, the identification of miRNAs that are changed in expression by environmental stresses, such as elevated CO2 concentration and temperature, can enable scientists to identify the biological pathways that are involved in regulating plant phenotypes in response to a changing environment.
“This is the first small RNA paper in the area of climate change,” Liu says. “CO2 has never been shown previously to regulate small RNA expression, and temperature-related small RNAs studies have been done previously, but only at freezing or low temperatures (the optimum temperature for Arabidopsis is at 23oC). We found that a 3-6oC increase in temperature from optimum temperature regulates a different set of miRNAs from other temperature-regulated miRNAs, but nearly all miRNAs affected by doubling the atmospheric CO2 concentration in an opposite direction.”
Using the next generation of sequencing in combination with statistical and computational analyses, Liu and her research team provided the first genome-wide profiling that demonstrated that increasing atmospheric CO2 concentration and temperatures within the ranges that will occur within this century can alter the expression of four functional groups of miRNAs: controlling flowering time, cell division and proliferation, stress responses, and potentially cell wall carbohydrate synthesis.
“These results indicate that under global warming conditions, plant grain and biomass production can be changed through altering the expression of these miRNAs,” Liu explains. “Given that nearly all of these miRNAs are conserved across multiple species, identification of these miRNAs provide us a starting ground to improve plant yields, particularly those that are economically important, to meet the upcoming challenges of global warming.”
Liu adds that one pathway, a miRNA (miR156)-regulated pathway, was identified to most likely mediate elevated CO2 concentration-induced early flowering. This result was obtained independently from other three relevant studies published at the same time in the journal Science and Elife, which demonstrated that sugar, the primary product of photosynthesis,can also regulate this pathway.
The study findings also raise other questions. Liu hopes to answer these questions by advancing the research.
“So far, we have only tested one concentration of CO2, and 3 to 6oC changes of temperature. We hope to get the data in a gradient of CO2 and temperature conditions. In addition, we also will be interested in understanding how these conditions affect miRNA expression in several other tissues — root, shoot, and flower tissues, for example, at different developmental stages,” she says. “In addition, further genetic investigation on identified miRNAs individually will shed new light on how their regulated pathways function in adaption to climate change.”
The researcher is now testing how combined conditions of elevated CO2 concentration and elevated temperature affect miRNAs expression. These are important experiments, she says, given that these two conditions are known to affect several miRNAs expression in the opposite directions. It is also practically more meaningful as climate change really has both CO2 concentration and temperature increases at the same time.
Liu is also preparing a manuscript that is related to how elevated CO2 concentration affects the genomic DNA methylation, which is another regulatory mechanism to regulate gene expression and genome stability.
In addition to Alison Liu, other researchers from Stony Brook University include Will Liao and Yijin Wu, doctoral graduate students in the Department of Applied Mathematics and Statistics; Kyeesha Bycoats (a medical student at Stony Brook); and undergraduate Zhifan Yang, of Department of Biomedical Engineering.
The research is supported by a grant from National Science Foundation.
Office of Media Relations | Newswise
Fine organic particles in the atmosphere are more often solid glass beads than liquid oil droplets
21.04.2017 | Max-Planck-Institut für Chemie
Study overturns seminal research about the developing nervous system
21.04.2017 | University of California - Los Angeles Health Sciences
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy