Tiny freshwater floating plant may help scientists to grow better crops

Duckweed, a tiny freshwater floating plant, is an excellent laboratory model for scientists to discover new strategies for growing hardier and more sustainable crops in an age of climate change and global population boom, a Rutgers-led study finds.

There is a need for new models to tackle complex molecular and ecological processes in plant biology using multidisciplinary approaches. Duckweeds are well suited to play an important role in these endeavors."

Eric Lam, Distinguished Professor in the Department of Plant Biology at Rutgers University-New Brunswick and Study's Senior Author

The study appears in the journal The Plant Cell.

Duckweed (family Lemnaceae), the smallest flowering and fastest growing plant on Earth, has many benefits, including providing wildlife habitat and being a sustainable source of food, livestock feed and biofuel. But also can spread rapidly and deprive ponds of oxygen, thereby killing fish and beneficial algae when not managed properly.

Named for its global distribution (like ducks) and its rapid growth (like weeds), duckweed was commonly used in lab research from 1950 to 1990 before being largely replaced in the genomics era by thale cress or mouse-ear cress (Arabidopsis thaliana), a model plant in the mustard family that offers facile genetics and a small genome.

But advances in genomic technologies over the past decade and the growing need to find alternative and more sustainable crops have renewed interest in duckweed as a model to enable discoveries in diverse fields from plant biology and ecology to chronobiology.

Researchers from Rutgers, the Salk Institute and an international team of specialists reviewed the anatomy, growth, physiology and molecular characteristics of duckweed, which has unique characteristics compared to other model plants that make them excellent candidates as model plants to tackle complex biological questions. One example is that genome sequences from multiple species of duckweed showed that these aquatic plants have a smaller number of genes compared to other model plant species, which may make duckweed a simpler plant model to characterize each gene's function.

In addition, recent studies published by collaborating teams at Rutgers and the Salk Institute revealed that the smallest member of the duckweed family, Wolffia, may economize its energy for growth by minimizing the level of gene control over the daily day-night cycle.

"We thus suggest that the duckweed plant family is an excellent platform to discover novel strategies for improved plant growth as well as environmental responses to optimize plant resilience and productivity," Lam said.

Although duckweed has adapted to an aquatic habitat, it has all the same types of genes and pathways as in well studied crop plants.

"As such, the novel strategies that we can learn from studying these small plants could potentially be used to re-engineer traditional crop plants to endow them with new traits," Lam said. "Furthermore, as the commercialization of duckweed-based bioproducts gathers steam, we and our co-authors are optimistic that the basic research we are carrying out in the laboratory will help translate duckweed's prodigious productivity into new sustainable crops that can augment traditional agricultural products."