TSRI scientists clone gene that regulates circadian rhythms in plants

August 03, 2000

La Jolla, CA, August 4, 2000 - Scientists at The Scripps Research Institute (TSRI) have cloned a gene that regulates circadian rhythms in plants, providing an increased understanding -- on a molecular level -- of the processes that enable organisms to anticipate and adapt to daily variations in the environment. According to Steve Kay, Ph.D., Professor of Cell Biology and an author of the study, "The work moves scientists in the direction of understanding how this gene helps plants keep accurate track of time, an extremely important capacity for organisms that are completely dependent on the daily cycle of light."

Further, researchers believe that understanding internal "clocks" in plants might also elucidate how clocks work in other species, including humans.

The study, "Cloning of the Arabidopsis Clock Gene TOC1, an Autoregulatory Response Regulator Homolog," appears in today's issue of Science. Its authors are Drs. Carl Strayer, Tokitaka Oyama, Thomas F. Schultz, Ramanujam Raman, David E. Somers, Paloma Mas, Satchidananda Panda, Joel A. Kreps, and Steve A. Kay.

Many biological processes -- the growth of fungi, activity of insects, changes in blood pressure in humans -- fluctuate daily, rising and falling at predictable times of day or night. They do so because the organisms possess internal clocks that time the rhythms. Plants, for example, use their clocks to get a jump on the day, gearing up their photosynthetic machinery and raising their leaves just before dawn. They also use their clocks to measure day length and in that way anticipate changes in the seasons - a system that determines when they shed their leaves or produce seeds or tubers in the fall, or make flowers or fruit in the spring.

Scientists have provided evidence of the existence of internal clock mechanisms by placing organisms in isolation chambers where they are prevented from seeing day/night cycles and in spite of this, their rhythms recur approximately every 24 hours. In the current study, scientists in the Kay lab worked with a mutant plant whose clock ran too fast, cycling approximately once every 21 hours.

To identify the gene responsible for this defect, the Kay group combined old-fashioned genetic techniques with modern technologies. They bred the mutant variety to normal plants and analyzed rhythms in the descendents. Using a gene from fireflies, regulated by the plant's clock, they could visualize the plants' glow rhythms. They also used information from a plant genome project, similar to the human genome project, to help correlate the defect in the glow rhythm with a particular region of a plant chromosome. Once the clock gene, called TOC1, was identified, researchers borrowed another glow gene - this one from a jellyfish - and hooked it up to TOC1 to see where it works within cells.

TOC1 was found in a member of the mustard family, a species named Arabidopsis, but similar genes likely regulate timing in species including corn, rice and wheat.
-end-
The study was funded by the National Institutes of Health and the National Science Foundation.

Scripps Research Institute

Related Cell Biology Articles from Brightsurf:

Deep learning on cell signaling networks establishes AI for single-cell biology
Researchers at CeMM have developed knowledge-primed neural networks (KPNNs), a new method that combines the power of deep learning with the interpretability of biological network models.

RNA biology provides the key to cell identity and health
Two papers in Genome Research by the FANTOM Consortium have provided new insights into the core regulatory networks governing cell types in different vertebrate species, and the role of RNA as regulators of cell function and identity.

Cell biology: Your number's up!
mRNAs program the synthesis of proteins in cells, and their functional lifetimes are dynamically regulated.

Cell biology -- maintaining mitochondrial resilience
Mitochondria cannot autonomously cope with stress and must instead call on the cell for help.

Cell biology: All in a flash!
Scientists of Ludwig-Maximilians-Universitaet (LMU) in Munich have developed a tool to eliminate essential proteins from cells with a flash of light.

A biology boost
Assistance during the first years of a biology major leads to higher retention of first-generation students.

Cell-free synthetic biology comes of age
In a review paper published in Nature Reviews Genetics, Professor Michael Jewett explores how cell-free gene expression stands to help the field of synthetic biology dramatically impact society, from the environment to medicine to education.

Scientists develop electrochemical platform for cell-free synthetic biology
Scientists at the University of Toronto (U of T) and Arizona State University (ASU) have developed the first direct gene circuit to electrode interface by combining cell-free synthetic biology with state-of-the-art nanostructured electrodes.

In a first for cell biology, scientists observe ribosome assembly in real time
A team of scientists from Scripps Research and Stanford University has recorded in real time a key step in the assembly of ribosomes -- the complex and evolutionarily ancient 'molecular machines' that make proteins in cells and are essential for all life forms.

Cell biology: Endocannabinoid system may be involved in human testis physiology
The endocannabinoid system (ECS) may be directly involved in the regulation of the physiology of the human testis, including the development of sperm cells, according to a study in tissue samples from 15 patients published in Scientific Reports.

Read More: Cell Biology News and Cell Biology Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.