Navigation Links
Discovery of 'master switch' for the communication process between chloroplast and nuclei of plants

Scientists have puzzled for years in understanding how plants pass signals of stress due to lack of water or salinity from chloroplast to nucleus. They know that chloroplasts ?the cellular organelles that give plants their green color ?have at least three different signals that can indicate a plant is under stress.

Given the challenges the environment will be facing over the coming decades through global warming, this puzzle piece has become more pressing for plant scientists, who hope that understanding the stress responses of plants will, in time, lead to new generations of plants that are, among other things, more drought- and stress-tolerant.

That is why a study that appeared in the internationally recognized journal, "Science," is considered an important step forward in the understanding of how chloroplasts communicate with a cell’s nucleus when stresses such as drought, heat, salinity or light become too great on the organism.

A research team that includes Shai Koussevitzky, a research associate in the University of Nevada, Reno’s College of Agriculture, Biotechnology and Natural Resources, as well as Ron Mittler, associate professor of Biochemistry and Molecular Biology, has determined that multiple distress signals in plants converge on a single pathway, which then channels the information to the nucleus. The study was part of a collaborative effort led by Joanne Chory, professor and director of the Plant Biology Laboratory at the Salk Institute for Biological Studies in La Jolla, Calif., and investigator with the Howard Hughes Medical Institute.

Koussevitzky, looking at the end of the signaling pathway, found the corresponding binding factor known that ABI4, a known plant transcription factor. It prevents light-induced regulatory factors from activating gene expression. Additional work in the project had determined that the chloroplast-localized, nuclear-encoded protein GUN1 is required for integrating multiple stress-der ived signals within the chloroplast. This work was conducted by the first co-author of the article, Ajit Nott, who was a research associate in Dr. Chory’s lab.

Many of the nuclear genes that encode chloroplast proteins are regulated by a "master switch" in response to environmental conditions. This "master switch," like a binary computer, can activate or de-activate certain sets of genes based on stress signaling processes.

"One of our suggestions in the paper is that ABI4 seems like a prime candidate to be the ‘master switch,? Koussevitzky said. "ABI4 binds to a newly identified sequence motif, and by doing so prevents light-induced regulatory factors from activating gene expression. It has a role in so many signaling processes in the plant, it might actually be the ‘master switch?that researchers have been looking for."

The discoveries are critical to future research efforts in designing new generations of plants, Mittler said.

"A lot of things that occur in the chloroplast are important for production, for growth, for response to the environment," he said. "So this is a very basic mechanism of communication between the chloroplast and the nucleus. It had been previously suggested that the elements in this process go through multiple pathways. This work shows that the elements actually go through this one particular route.

"Now we are in much better shape in solving the question of generating plants that can use marginal water, or marginal soil, and do so in a way that the plant won’t completely suppress its normal metabolisms and activate all of its stress metabolisms when faced with a lot of stress. If you want to generate a plant that is more tolerant, you need to deal with these two things."

Added Koussevitzky: "We’re trying to put the signaling pathways in the context of the plant’s stress response. It will take a little more tweaking, but at least knowing that it is going through a certain particular pat hway will enable researchers to design what the targets should be downstream from these pathways." Work for the project was supported by a grant from the Department of Energy, the Howard Hughes Medical Institute, EMBO long term and Howard Hughes Medical Institute fellowships.

Source:University of Nevada, Reno

Related biology news :

1. Fundamental Finding Yields Insight into Stem Cells, Cancer; Opens Door to Drug Discovery
2. Discovery of key proteins shape could lead to improved bacterial pneumonia vaccine
3. UCSD Discovery Shows How Embryonic Stem Cells Perform Quality Control Inspections
4. Discovery Could Lead To Novel Approaches In HIV Treatment
5. Discovery Promises Simpler Therapy for Sickle Cell Disease
6. Discovery may lead to better Candidiasis drug
7. Protein Discovery Could Unlock The Secret To Better TB Treatment
8. Discovery clarifies role of peptide in biological clock
9. Eliminate Data Analysis Bottlenecks in Drug Discovery
10. Discovery of New Dopamine Action May Yield Alternative Psychiatric Drugs
11. Discovery could be key to bioterrorism defense

Post Your Comments:

(Date:4/5/2017)...  The Allen Institute for Cell Science today announces ... portal and dynamic digital window into the human cell. ... application of deep learning to create predictive models of ... a growing suite of powerful tools. The Allen Cell ... publicly available resources created and shared by the Allen ...
(Date:4/5/2017)... KEY FINDINGS The global market ... CAGR of 25.76% during the forecast period of 2017-2025. ... for the growth of the stem cell market. ... MARKET INSIGHTS The global stem cell market is segmented ... The stem cell market of the product is segmented ...
(Date:4/3/2017)... April 3, 2017  Data captured by ... platform, detected a statistically significant association between ... to treatment and objective response of cancer ... to predict whether cancer patients will respond ... as well as to improve both pre-infusion potency ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... (PRWEB) , ... October 10, 2017 , ... ... Science Center’s FirstHand program has won a US2020 STEM Mentoring Award. Representatives of ... award for Excellence in Volunteer Experience from US2020. , US2020’s mission is to ...
(Date:10/10/2017)... , Oct. 10, 2017 SomaGenics announced ... the NIH to develop RealSeq®-SC (Single Cell), expected to ... profiling small RNAs (including microRNAs) from single cells using ... highlights the need to accelerate development of approaches to ... "New techniques for measuring levels of ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
(Date:10/9/2017)... ... October 09, 2017 , ... The ... medical marijuana products targeting the needs of consumers who are incorporating medical marijuana ... place in Phoenix, Arizona. , As operators of two successful Valley dispensaries, The ...
Breaking Biology Technology: