New research clarifies how hot nights are curbing crop yields for rice.
“Essentially, we found that warmer nights throw the rice plant’s internal clock out of whack,” says Colleen Doherty, an associate professor of biochemistry at North Carolina State University and corresponding author of a paper on the work in the journal PNAS.
“Most people think plants aren’t dynamic, but they are. Plants are constantly regulating their biological processes—gearing up for photosynthesis just before dawn, winding that down in the late afternoon, determining precisely how and where to burn their energy resources. Plants are busy, it’s just difficult to observe all that activity from the outside.”
And what researchers have learned is that the clock responsible for regulating all of that activity gets messed up when the nights get hotter relative to the days.
“This isn’t just an interesting scientific question, it’s a global food security issue.”
“We already knew that climate change is leading to increased temperatures globally, and that nighttime temperatures are rising faster than daytime temperatures,” Doherty says. “We also knew that warmer nights hurt rice production. But until now, we had very little insight into why warmer nights are bad for rice.
“We still don’t know all the details, but we’re narrowing down where to look.”
Research that addresses rice yield losses is important because rice is an essential crop for feeding hundreds of millions of people each year—and because a changing climate poses challenges for global food security.
To better understand how warm nights affects rice, Doherty worked with colleagues, including Krishna Jagadish of Kansas State University and Lovely Lawas of the International Rice Research Institute, to study the problem in the field. The researchers established two study sites in the Philippines. They used ceramic heaters or heat tends to manipulate temperatures in different areas of each study site.
A research team that Jagadish led used the ceramic heaters to maintain experimental plots at 2 degrees Celsius (3.6 degrees Fahrenheit) above the ambient temperature, and took samples from the rice plants every three hours for 24 hours. Control plots were not heated, but were also sampled every three hours during the same 24-hour period. The team repeated these tests four times. They later used the heat tents to validate the results from the ceramic heater tests.
Meanwhile, a team that Doherty led found that more than a thousand genes were being expressed at the “wrong” time when nighttime temperatures were higher. Specifically, hotter nights resulted in hundreds of genes—including many associated with photosynthesis—becoming active later in the day. Meanwhile, hundreds of other genes were becoming active much earlier in the evening than normal, disrupting the finely tuned timing necessary for optimal yield.
“It’s not clear what all of these genes do, but it is clear that these conflicting schedule shifts are not good for the plant,” Doherty says.
The researchers found that many of the affected genes are regulated by 24 other genes, called transcription factors. Of those 24, four of the transcription factors were deemed most promising for future study.
“We need to do additional work to figure out exactly what’s happening here, so that we can begin breeding rice that’s resilient against warmer nights,” Doherty says. “Rice is an important food crop. And other staple crops are also affected by hotter nights—including wheat. This isn’t just an interesting scientific question, it’s a global food security issue.”
The work took place with support from the US Department of Agriculture under a National Institute of Food and Agriculture grant.
Source: NC State
Related Books
Life After Carbon: The Next Global Transformation of Cities
by Peter Plastrik , John Cleveland
The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon
The Sixth Extinction: An Unnatural History
by Elizabeth Kolbert
Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon
Climate Wars: The Fight for Survival as the World Overheats
by Gwynne Dyer
Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon
From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.
This article originally appeared on Futurity
