Using supercomputers to analyze hundreds of thousands of genetic markers in a thousand plant samples, scientists say they have found how a common weed uses its genetic code to adapt to changes in its environment such as cold temperatures and drought.
The findings add to our knowledge of how plant life evolves, and could be used to help breed crops that are more adaptable to climate change, the researchers say.
“The basic motivation is that we’re interested in understanding how plants adapt to their environment, and especially how they adapt to harsh conditions,” said Jesse Lasky, a former Earth Institute Fellow and the lead author of a paper published in the journal Molecular Biology Evolution. Understanding those adaptations can help scientists better predict – and perhaps manipulate — how plants will respond to changing climate.
Lasky and colleagues focused on the common mustard green Arabidopsis thaliana, particularly useful for this research because it thrives in a variety of environments, from northwestern Africa to Scandinavia and Siberia. Arabidopsis has a relatively small genome – about 25,000 genes – and was the first plant to be fully sequenced, in 2000. It also has been extensively studied — researchers refer to it as the “lab rat” of the plant world, Lasky said – so there was a lot of data to look at.
The scientists looked at gene expression – how snippets of the material in the plant’s DNA create proteins and other chemical instructions that help regulate tolerance to cold, and at how gene expression in response to certain conditions can change. The researchers found evidence that evolutionary changes in gene expression allow populations to perform well in harsh environments.
The Arabidopsis study showed “good evidence that the evolution of gene expression is one way that plants evolve to adapt to changes in climate,” Lasky said.
Supercomputers at the University of Texas’s Advance Computing Center enabled Lasky and colleagues to process huge amounts of data, sorting through hundreds of thousands of genetic markers among 1,000 plant samples to find the parts of the plant’s genes most closely associated with adaptation to cold and drought.
“This is the best evidence yet that a plant’s genes sensitive to cold and drought will help a plant adapt to changes in its environment,” Thomas Juenger, a study co-author and a faculty member in the Department of Integrative Biology of The University of Texas at Austin, said in an interview recorded by the Texas Advanced Computing Center.
“If we can better understand how plants have evolved tolerances to natural environmental stresses, we may be able to learn how to manipulate or improve plants in an agricultural setting.”
Lasky, now a post-doctoral researcher in the Columbia University Department of Ecology, Evolution & Environmental Biology, said his current project uses a similar approach to examine how different varieties of sorghum respond to drought and drought stress.
(First posted on State of the Planet on Jan. 30, 2015.)