GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]

A Model System for Perennial Grasses

Panicum hallii genomes offer insights to drought tolerance.

The Science

Researchers have developed a genomic model to study drought tolerance in perennial grasses using Panicum hallii (Hall’s panicgrass), by generating two complete genomes from varieties that diverged over a million years ago. The hallii variety thrives in desert environments, while the filipes variety is less drought tolerant and is found in river and coastal environments.

The Impact

The perennial grass switchgrass (Panicum virgatum) is a candidate bioenergy feedstock with a complex genome with multiple copies of its chromosomes. Switchgrass has deep roots that allow it to access nutrients easily from a variety of soils and has a high tolerance of extreme water conditions such as drought and floods. The U.S. Department of Energy (DOE) supports research programs for developing methods for converting plant biomass into sustainable fuels for cars and jets. By studying a close relative model species like P. hallii, researchers can develop crop improvement techniques that could be applied to switchgrass.


Rising global temperatures are causing extreme weather events, ranging from prolonged droughts to extended periods of very heavy rainfall and severe flooding. With an ever-increasing global population, drought is an obstacle toward improving crop yields for food and fuel use.

In Nature Communications, a team led by Tom Juenger at the University of Texas (UT) at Austin and including researchers at the DOE Joint Genome Institute (JGI), a DOE Office of Science User Facility, report the culmination of nearly a decade of work to develop genomic resources for drought tolerance in perennial grasses. The team aims to apply the resources developed for P. hallii towards stress tolerance improvement in its more complex relative, the candidate bioenergy crop, switchgrass.

Through the JGI’s Community Science Program, JGI sequenced and assembled near-complete genomes of P. hallii var. hallii (99.2% complete) and P. hallii var. filipes (94.8% complete) and resequenced a host of natural collections from across the species range. With these high-quality reference genomes for P. hallii, researchers can identify and characterize the regulatory elements that influence adaptation and tolerance to stressors such as drought. This information can be applied toward improving crop yields in other grasses.

The team conducted several large-scale field experiments and analysis to find relationships between sequence variation and plant stress responses. For example, offspring of a cross between the hallii (HAL2) and filipes (FIL2) varieties were subjected to a monthlong drought, and then half the plants were watered just before harvesting. As HAL2 has adapted to severe summer droughts, these plants were better able to uptake soil water compared to the other plants. The team used QTL mapping to find the genomic regions that control gene expression and physiological responses to drought. They found that trans-regulating factors are important regulatory elements that determine drought responses in P. hallii.

The HAL2 and FIL2 genomes are available on the JGI’s plant portal Phytozome.

Read the paper: Nature Communications

Article source: DOE Joint Genome Institute (JGI)

Image credit: Amalia Díaz


Scientists engineer shortcut for photosynthetic glitch, boost crop growth 40%

Plants convert sunlight into energy through photosynthesis; however, most crops on the planet are plagued by a photosynthetic glitch, and to deal with it, evolved an energy-expensive process called photorespiration that drastically suppresses their yield potential. Researchers from the University of Illinois and U.S. Department of Agriculture Agricultural Research Service report in the journal Science that crops engineered with a photorespiratory shortcut are 40 percent more productive in real-world agronomic conditions.

Should researchers engineer a spicy tomato?

The chili pepper, from an evolutionary perspective, is the tomato's long-lost spitfire cousin. They split off from a common ancestor 19 million years ago but still share some of the same DNA. While the tomato plant went on to have a fleshy, nutrient-rich fruit yielding bountiful harvests, the more agriculturally difficult chili plant went defensive, developing capsaicinoids, the molecules that give peppers their spiciness, to ward off predators.

European wheat lacks climate resilience

The climate is not only warming, it is also becoming more variable and extreme. Such unpredictable weather can weaken global food security if major crops such as wheat are not sufficiently resilient – and if we are not properly prepared.