Navigation Links
How drought-tolerant grasses came to be

Durham, NC If you eat bread stuffing or grain-fed turkey this Thanksgiving, give thanks to the grasses a family of plants that includes wheat, oats, corn and rice. Some grasses, such as corn and sugar cane, have evolved a unique way of harvesting energy from the sun that's more efficient in hot, arid conditions. A new grass family tree reveals how this mode of photosynthesis came to be.

The results may one day help scientists develop more drought-tolerant grains, say scientists working at the U. S. National Evolutionary Synthesis Center.

From the grasslands of North America, to the pampas of South America, to the steppes of Eurasia and the savannas of the tropics, the grass family contains more than 10,000 species, including the world's three most important crops: wheat, rice and corn. We rely on grasses for sugar, liquor, bread, and livestock fodder.

Like all plants, grasses harvest energy from sunlight by means of photosynthesis. But grasses use two strategies that differ in how they take up carbon dioxide from the air and convert it into the starches and sugars vital to plant growth. The majority of grasses use a mode of photosynthesis called the C3 pathway, but many species especially those in hot, tropical climates use an alternate mode of photosynthesis known as C4. In hot, arid environments, C4 grasses such as maize, sugar cane, sorghum and millet have a leg up over C3 plants because they use water more efficiently.

An international team of researchers wanted to figure out how many times, and when, the C4 strategy came to be. To find out, they used DNA sequence data from three chloroplast genes to reconstruct the grass family tree. The resulting phylogeny represents 531 species, including 93 species for which DNA sequence data was previously unavailable.

"By working collaboratively across many labs, from the US to Argentina to Ireland to Switzerland with some people providing new plant material, and others doing the DNA sequencing we were able to get a lot done in a very short amount of time," said co-author Erika Edwards of Brown University.

The results suggest that the C4 pathway has evolved in the grasses more than 20 separate times within the last 30 or so million years, Edwards said.

What's most surprising, she added, is that C4 evolution seems to be a one-way street i.e., once the pathway evolves, there's no turning back. "We can't say whether it is evolutionarily 'impossible', or whether there simply hasn't been a good reason to do it, but it seems increasingly unlikely that any C4 grasses have ever reverted to the C3 condition," Edwards said.

"The new tree will be extremely useful for anyone who works on grasses," she added.

For example, scientists are currently trying to engineer the C4 photosynthetic pathway into C3 crops like rice to produce more stress-tolerant plants. By helping researchers identify pairs of closely related C3 and C4 species, the evolutionary relationships revealed in this study could help pinpoint the genetic changes necessary to do that.

"The next challenge is getting these species into cultivation and studying them closely, and ideally, sequencing their genomes," Edwards said.

The results will be published this week in the journal New Phytologist.


Contact: Robin Ann Smith
National Evolutionary Synthesis Center (NESCent)

Related biology news :

1. UMD to lead $5 million NSF-funded research partnership to develop drought-tolerant canola crops
2. Growing drought-tolerant crops inching forward
3. Plant scientists move closer to making any crop drought-tolerant
4. Warming climate could give exotic grasses edge over natives
5. Lawn of native grasses beats traditional lawn for lushness, weed resistance
6. Study rewrites the evolutionary history of C4 grasses
7. Grasses have potential as alternate ethanol crop, Illinois study finds
8. Alternative turfgrasses show potential for use on golf course fairways
9. First member of the wheat and barley group of grasses is sequenced
10. Brown biologist solves mystery of tropical grasses origin
11. Solutions to climate change: Using trees and grasses to capture carbon and produce energy
Post Your Comments:
Related Image:
How drought-tolerant grasses came to be
(Date:9/30/2015)... , Sept. 30, 2015  With nearly 300,000 ... number of new SCIs estimated to reach 12,500 annually, ... Southern California Resource Services for Independent Living (SCRS-IL) ... in California opening doors to ... of programs and services, notably assistive technology services and ...
(Date:9/29/2015)... SUNNYVALE, Calif. , Sept. 29, 2015 ... technology improves employee productivity while also saving energy ... features such as Low Power Active Mode and embedded ... workplace transformation Fujitsu today shows that ... of new and refreshed models to its enterprise desktop ...
(Date:9/28/2015)... 2015  The monitoring of vital signs, such ... is an essential component of patient assessment. Changes ... in a patient,s condition. However, in general care ... taken during routine observation rounds only once every ... between these observation rounds, the warning signs can ...
Breaking Biology News(10 mins):
(Date:10/9/2015)... ... 09, 2015 , ... From blood to food to medicine, ... from their surroundings for research, diagnostics, and cell therapy—also known as cell sorting—can ... Arbor-based startup Akadeum Life Sciences is developing a radically new product ...
(Date:10/8/2015)... 8, 2015   Intrexon Corporation (NYSE: ... the appointment of Joseph L. Vaillancourt as ... Nir Nimrodi who continues in his role as ... endeavors to generate sustainable, biologically based solutions to environmental ... he held a variety of key roles including, Vice ...
(Date:10/8/2015)... 8, 2015  ATCC, the premier global biological materials ... been selected by The Michael J. Fox Foundation for ... academic, pharmaceutical, and biotechnology organizations committed to speed a ... United States , and more than 5 million ... United States , and more than 5 million ...
(Date:10/8/2015)... 8, 2015 . ... --> Goldman Small Cap Research, a stock ... and microcap sectors, announced today that it has ... Biotech, Inc. (OTCQB - PMCB), a publicly traded, ... preparing treatments for cancer and diabetes. To view ...
Breaking Biology Technology: