Navigation Links
Salk scientists get to the root of plant cell fate

When Robert Burns compared his love to a red, red rose, he definitely wasn't referring to a topless mutant. That's because rather than being topped by a lovely, fragrant bloom, a rose mutant in the gene known as TOPLESS would be crowned by a homely second root.

Researchers at the Salk Institute for Biological Studies studying the frumpy wild mustard plant Arabidopsis thaliana rather than the elegant rose recently determined why plants with a defective TOPLESS gene form an extra root where the shoot should be. Their findings, published in the June 9th issue of the journal Science, suggest that it is possible to engineer a plant cell to develop in ways that better suit agricultural needs.

"If we know how a plant forms a root instead of a shoot, and that there is time in which to make such an important change, it might be possible to tell a plant to make a leaf instead of a flower," says the study's lead author, Jeffrey A. Long, Ph.D., an assistant professor in the Plant Molecular and Cellular Biology Laboratory. "We can now think about plant development in a different way."

The study, which included researchers from the laboratory of Elliot M. Meyerowitz, Ph.D., at the California Institute of Technology, specifically focused on understanding mutations in the TOPLESS gene that Long had previously identified in Arabidopsis thaliana, the first flowering plant to have its genome sequenced and a popular model organism for many aspects of plant biology.

Like animals, plants develop along a polar axis, but with a root on one end and a shoot on the other. A defective TOPLESS gene, however, causes plant embryos to develop into a seedling with two oppositely oriented root poles ?hence the gene's name. Long asked how mutations in TOPLESS can switch a plant cell's fate from shoot to root, hoping to discover how cells at the "basal" end of plant embryos become roots, while cells at the top or "apical" end become shoots that give rise to leaves, bra nches, and flowers. "We want to know how a plant can set aside a root and a shoot pole during embryogenesis and keep these functions separate," Long says.

The researchers found that the TOPLESS gene encodes a protein (TOPLESS) that is a transcriptional co-repressor. In plants and animals, co-repressors regulate gene expression by inhibiting the activity of transcription factors, which act as switches to activate target genes. Transcription factors control gene activity by binding to DNA sequences adjacent to a gene, but they are deactivated when they recruit and interact with co-repressors.

Long explains that the normal function of TOPLESS protein is to silence genes required for root development in the top or shoot half of a plant embryo. "In plants with a mutant TOPLESS, genes that should be kept off in order to produce a shoot aren't, so a root is produced," he explains.

Since transcriptional repression plays such a key role in animal embryonic development, the finding that a co-repressor controls polarity in plants was surprising, says Long. "We thought that because plants and animals are believed to have largely developed independently from each other, they would have used a different set of processes to maintain polarity," he says. "But they have a very similar toolbox of genes to set up some aspects of their body plan."

However, a critical difference between plants and animals in terms of polarity development is how much more tolerant plants are of manipulation. Long says, "In animals, early cell divisions are very important to development of polarity and if something goes awry with co-repressors, the animal quickly dies. But in plants, polarity can be changed much later in embryogenesis."

"Plants are so plastic. Our topless mutants can survive very well," he continues. "This suggests that the actual polarity in the embryo isn't fixed until late in development, and that offers us an opportunity to change the fate of the plant structure."


'"/>

Source:Salk Institute


Related biology news :

1. Wisconsin scientists grow critical nerve cells
2. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
3. UAB scientists discover the origin of a mysterious physical force
4. Fox Chase Cancer Center scientists identify immune-system mutation
5. Weizmann Institute scientists develop a new approach for directing treatment to metastasized prostate cancer in the bones.
6. U-M scientists find genes that control growth of common skin cancer
7. UCLA scientists transform HIV into cancer-seeking missile
8. RNA project to create language for scientists worldwide
9. Carnegie Mellon scientists develop tool that uses MRI to visualize gene expression in living animals
10. To control germs, scientists deploy tiny agents provocateurs
11. Leprosy microbes lead scientists to immune discovery
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/26/2016)... , April 27, 2016 ... "Global Multi-modal Biometrics Market 2016-2020"  report to their ... , The analysts forecast the global ... of 15.49% during the period 2016-2020.  ... of sectors such as the healthcare, BFSI, transportation, ...
(Date:4/15/2016)... CHICAGO , April 15, 2016  A ... companies make more accurate underwriting decisions in a ... offering timely, competitively priced and high-value life insurance ... health screenings. With Force Diagnostics, rapid ... and lifestyle data readings (blood pressure, weight, pulse, ...
(Date:4/14/2016)... TEL AVIV, Israel , April 14, 2016 /PRNewswire/ ... in Behavioral Authentication and Malware Detection, today announced the ... has already assumed the new role. Goldwerger,s ... for BioCatch, on the heels of the deployment of ... In addition, BioCatch,s behavioral biometric technology, which discerns unique ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... June 23, 2016   Boston Biomedical , ... compounds designed to target cancer stemness pathways, announced ... granted Orphan Drug Designation from the U.S. Food ... gastric cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin ... to inhibit cancer stemness pathways by targeting STAT3, ...
(Date:6/23/2016)... SPRING, Md. , June 23, 2016 A ... collected from the crime scene to track the criminal down. ... and the U.S. Food and Drug Administration (FDA) uses DNA ... Sound far-fetched? It,s not. The ... genome sequencing to support investigations of foodborne illnesses. Put as ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... YM (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. ... microbial tests introduced last year,” stated Bob Salter, Vice President of Regulatory and ...
(Date:6/23/2016)... 23, 2016  The Biodesign Challenge (BDC), a university ... to harness living systems and biotechnology, announced its winning ... New York City . ... showcased projects at MoMA,s Celeste Bartos Theater during the ... MoMA,s senior curator of architecture and design, and ...
Breaking Biology Technology: