GeneBites

As our climate changes, so too must our crops. Scientists have discovered genetic mechanisms in Atacama Desert plants that could help engineer crops resilient to extreme conditions.

Last summer, nearly half of the world’s population faced extreme heat for at least thirty days. These unprecedented rising temperatures and related climate change impacts affect nearly every aspect of our lives: ranging from extreme heat in the summer, to the kinds of food on our table. Many of the crops we consume on a day-to-day basis may not be able to survive these shifting temperatures. Maize crop yields, for example, are projected to decline 24% by 2030. As temperatures continue to rise, it is crucial that we understand how our fluctuating climate influences the very food that sustains us. Are there any crops on Earth already well-adapted to weather severe climates? How do they survive? A recent PNAS study led by NYU Biologist Gil Eshel aims to answer these questions by studying the diverse genetic mechanisms behind some plants’ ability to thrive in the Chilean Atacama desert, one of the driest places on Earth.

Researchers identified genes in Atacama plants that allow them to survive in extreme conditions.  They found that these plants are genetically primed to respond to “stressful” conditions – including high levels of salt, limited oxygen, and repairing damage to their DNA – which explains why they are able to survive in intense, high salinity environments with massive temperature fluctuations. Eshel and colleagues also saw an overrepresentation of genes involved in adenosine triphosphate (ATP) production and photosynthesis among Atacama plants, suggesting their increased investment in efficient energy production under harsh environments. Their analysis also pinpointed genes involved in the uptake of nitrogen, a nutrient limited in desert environments.In addition to identifying genes that allowed Atacama plants to thrive in the desert, the study identified genetic adaptations that contribute to these plants’ persistence. Some adaptations include stress response and energetic adaptations. For example, the Poaceae (grass family), the most dominant family of crops in Atacama, had genes for drought resistance and nutrient uptake that allowed them to survive in the harsh environment. These findings not only help us better understand just what it takes for crops to survive in extreme conditions, but also provide a potential blueprint toward genetically engineering crops able to withstand the potentially fluctuating environments of the future.

Finally, the team identified 265 genes that were found via positive selection pressure, a natural process where certain traits or genes become more common in a population because they provide an advantage for survival and reproduction. They found that these particular genes were linked to crucial functions such as light response, oxidative stress, and nutrient metabolism. These findings shed light on the ability to enhance traits in crops, such as photosynthetic efficiency, stress resilience, or nutrient use efficiency. 

As climate change ravages our environment with unanticipated consequences, genetics and agriculture will need to work together to innovate and ensure the survival of essential crops and subsequently, the human race. Understanding how Atacama plants thrive in the face of some of the world’s harshest climates today is one major key to engineering crops that will be able to survive tomorrow.

Edited by Richard Coca, Jayati Sharma, & JP Flores