Breakthrough research done earlier this year by a plant cell biologist at the University of California, Riverside has greatly accelerated scientists' knowledge on how plants and crops can survive difficult environmental conditions such as drought.
Working on abscisic acid (ABA), a stress hormone produced naturally by plants, Sean Cutler's laboratory showed in April 2009 how ABA helps plants survive by inhibiting their growth in times when water is unavailable – research that has important agricultural implications.
The Cutler lab, with contributions from a team of international leaders in the field, showed that in drought conditions certain receptor proteins in plants perceive ABA, causing them to inhibit an enzyme called a phosphatase. The receptor protein is at the top of a signaling pathway in plants, functioning like a boss relaying orders to the team below that then executes particular decisions in the cell.
Now recent published studies show how those orders are relayed at the molecular level. ABA first binds to the receptor proteins. Like a series of standing dominoes that begins to knock over, this then alters signaling enzymes that, in turn, activate other proteins resulting, eventually, in the halting of plant growth and activation of other protective mechanisms.
"I believe Sean's discovery is the most significant finding in plant biology this year and will have profound effects on agriculture worldwide," said Natasha Raikhel, the director of UC Riverside's Center for Plant Cell Biology, of which Cutler is a member. "Because the ABA receptor is so fundamentally important for understanding how plants perceive various environmental stresses, I am sure the strings of research that Sean's discovery sparks will be endless."
In only months since Cutler's discovery, six research papers in prestigious journals such as Science and Nature have been published that build on his work, a testament to the interest among plant scientists to nail down how exactly the stress signaling pathway works in plants. This intense activity in the field was expedited by Cutler's willingness to share information with colleagues before his own research was published – an open approach that is at odds with the often cutthroat competition in hot scientific areas.
"This intense interest by the scientific community will certainly accelerate the development of new agrichemicals that can be used to control stress responses in crops, and I believe we need to work openly to tackle problems of such great importance," said Cutler, an assistant professor of plant cell biology in the Department of Botany and Plant Sciences. "There is also tremendous interest from industry, and we are moving closer to designing both improved chemicals that can control drought tolerance in crops and improved receptor proteins that can be used to enhance yield under drought conditions. Ultimately, my vision is to combine protein and chemical design to usher in a fundamentally new approach to crop protection. These recent papers are an important step towards realizing that goal."
Determining how the chemical switch works
One of the six research papers that builds on Cutler's work is published online Nov. 18 in Nature. The research, led by Jian-Kang Zhu, a professor of plant cell biology at UCR, fleshes out the domino pathway from the receptor down to the proteins that control plant growth.
"Freshwater is a precious commodity in agriculture," Zhu said. "Drought stress occurs when there is not enough freshwater. We wanted to understand how plants cope with drought stress at the molecular level. Such an understanding is necessary if we want to improve the drought tolerance of crop plants through either genetic engineering or marker-assisted breeding."
In their Nature paper, Zhu and his colleagues report on how they reconstituted in a test tube the process of information transfer from receptor to phosphatase, and all the way downstream to the protein that turns the gene on or off, and then ultimately to the gene itself.
"The ABA signaling pathway we reconstituted is arguably the most important pathway for plants to cope with drought stress." Zhu said. "This is the first time the whole pathway has been reconstituted in vitro. What is emerging is a clear picture of how the chemical switch works – useful knowledge for designing improved chemical agents for application in crop fields."
Zhu explained that in vivo studies (done in the living body of the plant) involve thousands of proteins, which can complicate data interpretation. By doing the study in vitro (outside the living body of the plant) his lab avoids this problem, making it possible to determine the minimal number of components necessary and sufficient for the ABA response pathway.
Next in its research, the Zhu lab will use the knowledge of the ABA response pathway to make transgenic plants that will have substantially higher levels of drought tolerance, achieved by manipulating the levels and activities of the key components of the pathway. The lab also plans to investigate how drought stress triggers the production of ABA.
Zhu was joined in the research by Cutler and UCR's Hiroaki Fujii, Viswanathan Chinnusamy, and Sang-Youl Park. Americo Rodrigues, Silvia Rubio, Regina Antoni and Pedro L. Rodriguez of the Instituto de Biología Molecular y Celular de Plantas, Spain; and Jen Sheen of the Massachusetts General Hospital also collaborated on the study.
Zhu was funded by a grant from the National Institutes of Health. Currently, he has an appointment also at the King Abdullah University of Science and Technology, Saudi Arabia.
The other five research papers that Cutler's research inspired discuss the molecular structure of the ABA receptor, showing in atomic detail how ABA functions to trigger signaling.
The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 18,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.
A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. To learn more, call (951) UCR-NEWS.
Iqbal Pittalwala | EurekAlert!
Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country
New data unearths pesticide peril in beehives
21.04.2017 | Cornell University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences