It is not an easy life in Chile's Atacama desert. This harsh desert is known for its hostile nature and reputation as the planet's most dry non-polar desert.
Despite all odds, life survives in these barren, uncultivated areas, which have a long history of agriculture dating back thousands of years.
It is more important than ever to identify the reasons behind these unorthodox successes. This could help us understand how food grows in a world that is becoming increasingly hotter and dryer every year.
Scientists have discovered some of these hidden tricks in a new study. They have identified the genetic basis of a variety of adaptations that allow plant life to thrive even in the harsh, dry conditions of the Atacama desert.
Gabriela Carrasco, a researcher, studies plant samples from the Atacama desert. (Melissa Aguilar)
Gloria Coruzzi, a plant systems biologist at New York University, says that it is crucial to discover the genetic basis for crop production and resilience in an era of climate change.
Coruzzi led an international research team that studied Atacama plant diversity in 22 desert sites over a 10-year period. They also transported soil and plant samples back to the laboratory, where they were frozen in liquid nitrogen in order to preserve them for genetic analysis.
The transcriptomes of 32 of the most dominant desert plants were sequenced. These transcriptomes were then compared to 32 closely related species from other places, none with genetic adaptations for Atacama's environment.
Coruzzi explains that the goal of this evolutionary tree was to identify changes in the amino acid sequences encoded by the genes supporting the evolution of Atacama's adaptation to desert conditions.
The comparison technique, an example of what's known as phylogenomics, yielded 265 positively chosen genes. This suggests that they were correlated with mutations which might confer benefits in the Atacama desert.
Further analysis revealed that 59 genes were also found in Arabidopsis (one of the most studied model organisms of plant biology). These genes have been linked to physiological or molecular processes that can increase plant resilience under extreme environmental conditions, according to the researchers.
These genes, which have been positively selected in Atacama desert plant species, are known to allow Arabidopsis to withstand extreme radiation and temperature stress, regulate flower development and flowering times, protect against pathogens and aid with water and nutrient intake.
It almost sounds like an evolutionary toolkit to help plants survive in the most hostile environments on Earth. The good news is that many of these genetics are also found in food crops species, which could give us a better understanding of where to plant them as the world heats up, as well as how to tweak and future-proof them.
Rodrigo Gutirrez, a senior author and plant systems biologist at the Pontifical Catholic University of Chile, said that the work is "directly relevant to regions around world that are becoming more arid with factors like drought, extreme temperature and salt in soil posing an important threat to global food supply."
"As some Atacama plants have close relatives to staple crops like potatoes and legumes, the candidate genes that we identified are a genetic goldmine for engineering more resilient crops. This is a necessity due to the increasing desertification of the planet.
These findings are published in PNAS.
