Navigation Links
How plants sense low oxygen levels to survive flooding
Date:10/23/2011

RIVERSIDE, Calif. 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.


'/>"/>

Contact: Iqbal Pittalwala
iqbal@ucr.edu
951-827-6050
University of California - Riverside
Source:Eurekalert  

Related biology news :

1. Plants feel the force
2. Crater shapes explained, how carnivorous plants bite, and doubts about faster-than-light neutrinos
3. Protein plays role in helping plants see light
4. Progress towards developing plants that accommodate climate change
5. Productivity of land plants may be greater than previously thought
6. The breathtaking dance of plants
7. Manipulating plants circadian clock may make all-season crops possible
8. Harnessing the power of plants
9. UBC researchers discover key mechanism that regulates shape and growth of plants
10. Plant biologists dissect genetic mechanism enabling plants to overcome environmental challenge
11. Some plants duplicate their DNA to overcome adversity
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
How plants sense low oxygen levels to survive flooding
(Date:12/22/2016)... VIEW, Calif. , Dec. 20, 2016  As part ... levels, 23andMe, the leading personal genetics company, recently released its ... Me . The book focuses on the topics of ... Next Generation Science Standards (NGSS) taught in elementary school classrooms ... second in a series by illustrator Ariana Killoran , ...
(Date:12/16/2016)... 16, 2016   IdentyTechSolutions America LLC , ... and solutions and a cutting-edge manufacturer of software ... is offering seamless, integrated solutions that comprise IDT ... The solutions provide IdentyTech,s customers with combined physical ... from crime and theft. "We are ...
(Date:12/15/2016)... ... and Markets has announced the addition of the "Global Military Biometrics ... forecasts the global military biometrics market to grow at a CAGR of ... prepared based on an in-depth market analysis with inputs from industry experts. ... coming years. The report also includes a discussion of the key vendors ...
Breaking Biology News(10 mins):
(Date:1/19/2017)... Jan. 19, 2017  ArmaGen, Inc., today announced ... Ph.D., as chief executive officer, as well as ... brings to ArmaGen more than 17 years of ... development of biotherapeutics and pharmaceuticals. ... diverse experience and skillset necessary to lead ArmaGen ...
(Date:1/19/2017)... NY (PRWEB) , ... January 19, 2017 , ... FireflySci ... an exponential rate. The tremendous growth is accounted to two main factors. ... table and the expanding network of vendors supplying FireflySci products all around the world. ...
(Date:1/19/2017)... , Jan. 18, 2017 Acupath Laboratories, ... announces the formation of an Executive Committee that will ... beyond. John Cucci , a 15-year ... from Director of Business Development to Chief Sales ... Mr. Cucci served in senior sales leadership roles at ...
(Date:1/18/2017)... 18, 2017   Boston Biomedical , an industry ... target cancer stemness pathways, will feature data from two ... the 2017 ASCO Gastrointestinal Cancers Symposium, held from January ... Napabucasin is an orally-administered investigational agent designed ... Cancer stem cells (CSCs) possess the property of ...
Breaking Biology Technology: