Navigation Links
Computational analysis shows that plant hormones often go it alone

Unlike the Three Musketeers who lived by the motto "All for one, one for all," plant hormones prefer to do their own thing. For years, debate swirled around whether pathways activated by growth-regulating plant hormones converge on a central growth regulatory module. Now, the cooperation model is challenged by researchers at the Salk Institute for Biological Studies. They show that each hormone acts largely independently in the Aug. 11 issue of Cell.

The Salk team found that specific plant hormones often activate different factors rather than a common target. "This result was completely unexpected because hormones with similar effects on plant growth seem to act on different gene sets," says the study's lead author Joanne Chory, Ph.D., a professor in the Plant Biology Laboratory and investigator with the Howard Hughes Medical Institute.

Plants rely on hormones, which act as chemical messengers to regulate every aspect of their biology. Growth, for example, is stimulated by multiple hormones -- brassinosteroids, auxins and gibberellins among them. The fact that these and several other hormones stimulate plant growth suggested to some investigators that eventually they all switch on the same growth-promoting genes.

To test that idea, the Chory team poured over data derived from the new gene-chip technology, in which samples of almost every gene expressed in a cell are spotted onto a tiny glass slide known as a microarray and analyzed under different physiological conditions. Although the analysis sounds complex, it answers a simple question: After stimulation with seven different growth hormones, are the same or different genes activated?

The teamwork model would predict yes, but Chory's team found otherwise. Co-lead authors Jennifer L. Nemhauser, Ph.D., a former postdoctoral fellow in Chory's lab and now assistant professor at the University of Washington in Seattle, and Fangxin Hong, Ph.D., a biostatistician in Chory's lab, found that each of the seven hormones activated largely its own repertoire of target genes. "We found shockingly little overlap," Nemhauser reports.

The microarray data used by Chory's team were collected as part of a multinational effort known as the AtGenExpress project cataloguing gene expression in the model plant Arabidopsis thaliana, which has become the lab mouse of the plant world. The laboratory of Detlef Weigel, Ph.D., an adjunct professor in the Laboratory for Plant Biology at the Salk and a professor at the Max Plank Institute for Developmental Biology in Tübingen, Germany, is one of the most prolific providers of micro-array data for Arabidopsis.

Participants in the project send results from their lab's microarray analysis of Arabidopsis genes to a publicly available database, where data is shared by colleagues investigating diverse biological questions. "The data was there but nobody had compared the effects of different growth hormones on gene expression side by side," says Nemhauser.

The amount of data analyzed by the Chory group was enormous. The activity of about 22,000 genes, each detected by on average 15 detectors after treatment with the seven hormones, was crunched--not once--but twice, resulting in roughly 14 million data points. "Since we didn't generate any of the data ourselves, we had to perform extensive quality controls to extract meaningful information," explains Hong.

The Salk researchers' analysis revealed that surprisingly few genes were switched on by multiple hormones. And when more than one hormone did initiate a similar program, such as activating genes encoding proteins called "expansins" that loosen plant cell walls to allow for growth, the investigators found that they mobilized different members of the expansin gene family.

"The data analysis showed that there is likely a complex set of interactions between the levels of hormones," explains Chory, "which suggests that long-term effect s of all hormone treatments represent a 'domino effect' that resets many systems within the plant."

Combining traditional biological approaches with computational analysis will move plant biologists closer to answering the age-old question of how plants grow, the Salk researchers predict. "Microarrays are very useful for those of us studying physiology and development. They can reveal new interactions, or lack thereof, between biological processes and identify candidates for direct targets of transcription factors controlling development," says Chory.


'"/>

Source:Salk Institute


Related biology news :

1. Supercomputer Dedicated To Bioengineering, Computational Biology Installed
2. Institute for Systems Biology Symposium Addresses Need for Better Computational Tools
3. Computational Method Speeds Mapping of Cell Signaling Networks
4. Computational verification of protein-protein interactions by orthologous co-expression
5. Computational Tool Predicts How Drugs Work In Cells, Advancing Efforts To Design Better Medicines
6. Computational model simulates AZT metabolism in mitochondria
7. GATA: a graphic alignment tool for comparative sequence analysis
8. Global analysis of membrane proteins
9. Doctors closer to using gene analysis to help trauma patients
10. Agilent Technologies new genome analysis technology set to accelerate Australia fight against mesothelioma
11. New miniaturised chip dramatically reduces time taken for DNA analysis
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/17/2017)... , April 17, 2017 NXT-ID, Inc. ... company, announces the filing of its 2016 Annual Report on Form ... Exchange Commission. ... Form 10-K is available in the Investor Relations section of the ... on the SEC,s website at http://www.sec.gov . 2016 ...
(Date:4/11/2017)... -- Research and Markets has announced the addition of ... offering. ... market to grow at a CAGR of 30.37% during the period ... has been prepared based on an in-depth market analysis with inputs ... growth prospects over the coming years. The report also includes a ...
(Date:4/5/2017)... -- The Allen Institute for Cell Science today announces the ... and dynamic digital window into the human cell. The ... of deep learning to create predictive models of cell ... growing suite of powerful tools. The Allen Cell Explorer ... available resources created and shared by the Allen Institute ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased ... of over 5.5 million people each year. Especially those living in larger cities are ... - based in one of the most pollution-affected countries globally - decided to take ...
(Date:10/11/2017)... Florida (PRWEB) , ... October 11, 2017 , ... ... Drug Administration (FDA) has granted orphan drug designation to SBT-100, its novel anti-STAT3 ... for the treatment of osteosarcoma. SBT-100 is able to cross the cell membrane ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing rights that give ... Liposomal Nanoparticle), a technology developed in collaboration with Children’s Hospital Los Angeles ...
(Date:10/10/2017)... ... , ... Dr. Bob Harman, founder and CEO of VetStem Biopharma, Inc. ... The event entitled “Stem Cells and Their Regenerative Powers,” was held on August ... MPVM was joined by two human doctors: Peter B. Hanson, M.D., Chief of Orthopedic ...
Breaking Biology Technology: