Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antagonistic genes control rice growth

17.12.2009
Scientists at the Carnegie Institution, with colleagues,* have found that a plant steroid prompts two genes to battle each other—one suppresses the other to ensure that leaves grow normally in rice and the experimental plant Arabidopsis thaliana, a relative of mustard. The results, published in the December 15, 2009, issue of The Plant Cell, have important implications for understanding how to manipulate crop growth and yield.

In plants, steroid levels reflect environmental and internal signals and control many processes. Steroid hormones called brassinosteroids (BRs) start their action on the surface of the cell and, through a molecular relay, send signals into the cell's nucleus to turn on or off specific genes, particularly those that are critical to regulating plant growth and development. Although a lot has been discovered about how the steroid affects genes in Arabidopsis, much less was known in crop plants such as rice.

Co-author Zhi-Yong Wang at Carnegie's Department of Plant Biology explained the work: "We knew that the steroid is very important for activating genes that control cell growth in Arabidopsis as well as in rice. One of the most sensitive responses to the steroid is leaf bending in rice, caused by expansion of the upper cells at the joint between leaf blade and leaf sheath. We wanted to determine how the steroid functioned in rice. We found that the steroid affects two genes encoding (or producing) proteins that turn other genes on or off; they are called transcription factors. In rice, when a gene called Increased Leaf Inclination1 (ILI1) is turned on, it causes leaf bending. Interestingly, we found that the ILI1 protein also binds to another transcription factor, called IBH1, and inhibits its function. When there is too much ILI1 protein, the leaves bend excessively making the plant shaggy. When IBH1 level is high, cell growth is stopped at the joint and the rice is very erect, taking up less space. In normal rice plants the balance between ILI1 and IBH1 keeps growth in check."

This pair of genes provides a unique tool to control the leaf angle, which is important for crop yield because erect leaves improve light capture and allows rice plants to be planted at higher density for a higher yield per hectare.

Through a series of experiments, the researchers determined how the steroid and genes interact. They found that brassinosteroid oppositely regulate these genes—ILI1 was activated and IBH1 was repressed. As such, the steroid tips the balance between their protein products, ILI1 and IBH1, to initiate cell growth.

"It appears that the steroid causes the IBH1 genes to stop the production of IBH1 protein, and in the meantime increases the production of the ILI1 protein, which turns off IBH1's inhibition of cell growth. This ensures that the cell grows to just the right length according to the level of steroid," commented Wang.

The researchers performed similar experiments on the mustard, which showed that steroid interacted with the mustard genes the same way. "Since similar genes are doing the same thing in these different plants, this process is likely to be very old and found in many different higher plants. The more we learn about such mechanisms, the closer we will come to better engineering crops to feed a growing population," concluded Wang.

The work was supported by the National Science Foundation of China; The National Institute of Health; the Ministry of Education, Culture, Sports, Science and Technology of Japan; and the Carnegie Institution.

*Colleagues on the study are from the following institutions: Institute of Botany, Chinese Academy of Sciences; Chinese Academy of Agricultural Sciences; Department of Plant Biology, Carnegie Institution; Yonsei University, Korea; RIKEN Advanced Science Institute, Japan.

The Carnegie Institution for Science (www.CIW.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

Zhi-Yong Wang | EurekAlert!
Further information:
http://www.ciw.edu

More articles from Life Sciences:

nachricht Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.

nachricht Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>