Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


How plants sense low oxygen levels to survive flooding

Breakthrough finding by UC Riverside and the University of Nottingham researchers could lead to production of flood-tolerant crops

As countries such as Pakistan, Bangladesh, Vietnam and parts of the United States and United Kingdom have fallen victim to catastrophic flooding in recent years, tolerance of crops to partial or complete submergence is a key target for global food security. Starved of oxygen, crops cannot survive a flood for long periods of time, leading to drastic reductions in yields for farmers.

Experts at the University of California, Riverside and The University of Nottingham now report they have discovered how plants sense low oxygen levels to survive flooding – a finding that could lead eventually to the production of high-yielding, flood-tolerant crops, benefiting farmers, markets and consumers everywhere.

Specifically, the researchers identified the molecular mechanism involved. This mechanism controls key plant proteins, causing them to be unstable when oxygen levels are normal. When roots or shoots are flooded and oxygen levels drop, these proteins become stable.

"When a plant cell is starved for oxygen, it cannot efficiently generate adenosine triphosphate or ATP, the high-energy molecule plants use for energy storage," explained Julia Bailey-Serres, one of the key researchers participating in the study and a professor of genetics in the Department of Botany and Plant Sciences at UC Riverside. "Because the plant cannot generate enough energy to sustain normal growth, it tries a different approach: it taps into its energy reserves, resulting in more sugars breaking down, as opposed to when oxygen is available, in order to produce ATP. These subtle changes in metabolism are characteristic of low oxygen stress in plant and animal cells. It's similar to the production of lactic acid in our bodies when we exercise. We produce lactic acid as a by-product because we are not producing energy aerobically."

The study describing the oxygen-sensing protein turnover mechanism appears online Oct. 23 in Nature.

"The mechanism controls key regulatory proteins called transcription factors that can turn other genes on and off," explained Michael Holdsworth, a professor of crop science at the University of Nottingham who co-led the research project with Bailey-Serres. "It is the unusual structure of these proteins that destines them for destruction under normal oxygen levels, but when oxygen levels decline, they become stable. Their stability results in changes in gene expression and metabolism that enhance survival in the low oxygen conditions brought on by flooding. When the plants return to normal oxygen levels, the proteins are again degraded, providing a feedback control mechanism."

Bailey-Serres, a member of UCR's Institute for Integrative Genome Biology and an international expert in plant responses to flooding, has been working since 2003 on the cellular mechanisms that regulate submergence tolerance in rice. Her lab has focused on SUB1A, a gene responsible for tolerance of complete submergence in rice and found only in some low-yielding rice varieties in India and Sri Lanka. Her lab is renowned for having characterized the roles of the SUB1A gene that has been bred into modern rice varieties to allow plants to survive two weeks or longer of complete submergence caused by Monsoon rains.

In the current work, the researchers performed their experiments on Arabidopsis, a small flowering plant used widely in plant biology laboratories as a model organism. SUB1A-like proteins are present in other plants, including Arabidopsis. While the protein turnover mechanism targets SUB1A-like proteins in Arabidopsis, the researchers found, to their surprise, that rice SUB1A is resistant to the protein turnover mechanism.

"We think that SUB1A's ability to evade destruction by the protein turnover mechanism under normal oxygen levels may allow it to provide its benefit to submerged rice plants," Bailey-Serres said. "The SUB1A gene is switched on by ethylene gas that accumulates inside cells during submergence. Since the protein does not require a scarcity of oxygen to be stable, it can go to work early to aid the plant."

Holdsworth, an international expert in seed biology and a protein turnover mechanism called the "N-end rule pathway of targeted proteolysis," had the first hint of the discovery while investigating the regulation of gene expression during seed germination. He connected the N-end rule pathway to the Arabidopsis SUB1A-like proteins and their regulation of genes associated with low oxygen stress that Bailey-Serres has studied extensively in Arabidopsis.

"The puzzle pieces fell quickly into place when the expertise of the two teams was combined," he said.

The research team expects that over the next decade scientists will be able to manipulate the protein turnover mechanism in a wide range of crops prone to damage by flooding.

Bailey-Serres and Holdsworth and were joined in the study by Seung Cho Lee (co-first author), a graduate student, and Takeshi Fukao, an associate specialist in botany and plant sciences, at UCR; Daniel Gibbs (co-first author), Nurukhikma Md Isa, Silvia Gramuglia, George W. Bassel, and Cristina Sousa Correia at The University of Nottingham; Francoise Corbineau at the Université Pierre & Marie Curie, France; and Frederica L. Theodoulou at Rothamsted Research, United Kingdom.

Bailey-Serres's group was supported by grants from the US Department of Agriculture National Institute of Food and Agriculture and the US National Science Foundation. Holdsworth's group was funded for this research project by the UK Biotechnology and Biological Sciences Research Council.

The University of California, Riverside ( 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 has exceeded 20,500 students. The campus will open a medical school in 2013 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. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Enormous dome in central Andes driven by huge magma body beneath it

25.10.2016 | Earth Sciences

First time-lapse footage of cell activity during limb regeneration

25.10.2016 | Life Sciences

Deep down fracking wells, microbial communities thrive

25.10.2016 | Earth Sciences

More VideoLinks >>>