Seeds in space: Cosmic exposure of crops could unlock benefits for food security on Earth

12 Jan 2023 --- Seeds of arabidopsis, a plant commonly used in genetic experiments, and sorghum, a nutrient-packed grain used for human consumption and animal feed, are being exposed inside and outside of the International Space Station (ISS) for three months to conditions prevailing in space, such as microgravity and cosmic radiation.

Arabidopsis and sorghum seeds have been selected because there is already a large bank of genetic knowledge to draw up for analysis and comparison.

Arabidopsis has been studied extensively by plant botanists and geneticists. At the same time, sorghum is a crop of the semi-arid tropics, a grain grown in many developing countries for food.

The latest round of analyses will help understand whether cosmic radiation and space conditions have a uniquely valuable effect on crop improvement and could benefit people on Earth. 

Seeds launched into space last November have now been positioned inside and outside the ISS to be exposed to the full range of cosmic radiation and extreme temperatures.

Exploring the effects of cosmic radiation 
This astrobotany investigation, an undertaking of the International Atomic Energy Agency (IAEA) and the Food and Agriculture Organization of the United Nations (FAO), aims to explore the effects of cosmic radiation on seeds as part of research into strengthening crop varieties to withstand the impact of climate change and increase global food security. 

The latest round of analyses will help understand whether cosmic radiation and space conditions have a uniquely valuable effect on crop improvement and could benefit people on Earth.The aim is to determine whether the harsh conditions of space, such as extremes of temperature and cosmic radiation, will lead to evolutionary changes in the seeds and, in turn, whether those changes could help plants become more resilient in the face of increasingly difficult growing conditions on Earth.

“We have a responsibility to explore nuclear techniques that could make a positive difference to human health and food supplies,” says Najat Mokhtar, IAEA deputy director general and head of the department of Nuclear Sciences and Applications. 

“As the world grapples with adapting to the consequences of climate change, it is crucial to speed up plant breeding research to find adequate and cost-effective solutions.”

“Further R&D is needed by the smallholder food producers most vulnerable to climate change,” explains FAO deputy director-general Maria Helena Semedo. 

She believes the increasingly harsh growing conditions threaten food production, a situation the FAO hopes space science will contribute to change by promoting the development of resilient, nutritious crop varieties in abundance.

Cosmic radiation in plant breeding
Spontaneous mutations arising from exposure to different environmental conditions are the bases of evolution in all organisms. The IAEA and FAO, through the joint FAO/IAEA Centre, have a long history of supporting countries in finding new crop varieties with desirable traits through radiation-induced mutagenesis techniques, improving food and nutrition security and farmers’ income.

The joint FAO/IAEA Centre, based in Vienna, Austria, has been speeding up plant breeding research using radiation to develop new agricultural crop varieties for almost 60 years. 

In the history of plant agriculture, natural selection or evolution breeding, also called mutation breeding, has been the driver of crop domestication and plant breeding. 

They are responsible for the genetic adaptation of plants to their changing environments and lead to the improvement of crops. So far, over 3,400 new varieties of more than 210 plant species have been developed using radiation-induced genetic variation and mutation breeding – including numerous food crops, ornamentals and trees used by farmers in 70 countries.

When the seeds return from space, currently expected in April 2023, they will be germinated and grown in the IAEA greenhouses and laboratories in Seibersdorf, managed by the Joint FAO/IAEA Centre, and examined for DNA structural variations and biological effects. 

Arabidopsis and sorghum seeds were launched into space from NASA’s Wallops Flight Facility in Virginia, US, on November 7, 2022, as part of the cargo load of the CRS2 NG-18 mission to the ISS. 

On December 13, half the seeds were moved to the ISS Nanoracks external platform. The other half have been kept inside the ISS for comparison, exposed mainly to microgravity and some radiation levels.

Edited by Elizabeth Green