Nav: Home

Rice plants evolve to adapt to flooding

July 12, 2018

Although water is essential for plant growth, excessive amounts can waterlog and kill a plant. In South and Southeast Asia, where periodic flooding occurs during the rainy season, the water depth can reach several meters for many months.

Rice varieties known as "deepwater rice" have developed a unique strategy to ensure their own survival. Deepwater rice grows normally in shallow water but in heavy floods increases its height in keeping with rising water levels, to enable the plants to ride out lengthy floods.

A research team comprising Takeshi Kuroha at Tohoku University, Motoyuki Ashikari at Nagoya University, Susan R. McCouch at Cornell University and colleagues in Japan and the U.S.A., have discovered a gene in rice that is critical to its survival in flood conditions. They have also shed light on its molecular function and evolutionary history.

The research group identified the SD1 (SEMIDWARF1), as a key gene responsible for the deepwater rice's response. The SD1 encodes a biosynthesis enzyme of gibberellin - a plant hormone. The gene orchestrates the deepwater rice response via a unique gain-of-function allele. When submerged, rice accumulate ethylene, a gaseous plant hormone. Deepwater rice amplify a signaling relay in which the SD1 gene is transcriptionally activated by an ethylene-responsive transcription factor, OsEIL1a.

The resulting SD1 protein directs increased synthesis of gibberellins, largely one of gibberellin species, GA4, which promote vertical growth in the plant. Further analysis revealed that this conditionally functional variation evolved first in a wild ancestor and was then a target of selection during the domestication of cultivated rice adapted to deepwater environments in Bangladesh.

The SD1 gene is well-known as the Green Revolution gene in rice, where a loss-of-function allele of SD1 confers short plant height, providing lodging resistance and increases the harvest index, generating greater grain yields under high input agricultural systems (Figure 3- left).

A transcriptional gain-of-function allele of the same gene enables deepwater rice to adapt to flooding via the opposite phenotypic response - an increase in plant height. The ability of SD1 to function in such diverse roles in cultivated rice highlights the inherent plasticity of plant response to its environment.

"Extreme weather events caused by climate change could affect food production worldwide," said Kuroha. "Farmers will need to diversify their methods and the cryptic genetic variation found in wild rice genes may offer adaptive solutions for growing resilient crops."
-end-


Tohoku University

Related Flooding Articles:

Urban development reduces flash flooding chances in arid West
Urban development in the eastern United States results in an increase in flash flooding in nearby streams, but in the arid West, urbanization has just the opposite effect, according to a Penn State researcher, who suggests there may be lessons to be learned from the sharp contrast.
NASA's Aqua satellite reveals flooding in Japan from Typhoon Hagibis
Typhoon Hagibis made landfall in Japan over the weekend of October 12 and 13, bringing damaging winds, rough surf and flooding rains.
Extreme flooding from storm surge and heavy precipitation projected to increase higher probability of compound flooding from precipitation and storm surge in Europe under anthropogenic climate change
Risk of compound flooding, which can result when rapid sea level rises associated with storms occur along with heavy rains, is currently concentrated along Mediterranean countries but will greatly increase for Northern European in the future as the climate warms, according to a new modeling study.
Changing climate linked to major changes in flooding across Europe
The impact of a changing climate on the severity of flooding has been demonstrated in the largest-scale study of its kind.
Researchers develop better way to determine coastal flooding risk
Researchers have developed a new methodology for building computer models that paves the way to better understanding the flood risks faced by coastal communities.
Houston's urban sprawl increased rainfall, flooding during Hurricane Harvey
Princeton and University of Iowa researchers found that Houston's urban landscape directly contributed to the torrential rainfall and deadly flooding of Hurricane Harvey in 2017.
Evidence of outburst flooding indicates plentiful water on early Mars
The presence of water on Mars has been theorized for centuries.
Climate-induced soil changes may cause more erosion and flash flooding
The Earth beneath our feet isn't usually the first thing that comes to mind when people think about the impacts of climate change.
NASA captures monsoon rains bringing flooding to India
NASA provided estimates monsoon rainfall that affected India from Aug.
Rice plants evolve to adapt to flooding
Although water is essential for plant growth, excessive amounts can waterlog and kill a plant.
More Flooding News and Flooding Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.