Spaceflight-Induced Hypoxic-ROS Signaling (APEX-05)

Science Objectives

When grown in the confines of the International Space Station (ISS), plants do not seem to get enough air and as a result, exhibit a stress response in their genes and proteins. The Spaceflight-induced Hypoxic/ROS Signaling (APEX-05) experiment grows different wild and mutant varieties of Arabidopsis thaliana, in order to understand how their genetic and molecular stress response systems work in space. The plants grow from seeds in the Veggie plant growth facility aboard the ISS, are frozen, and returned to Earth for detailed laboratory analysis.

Status

The experiment has concluded, and science is being evaluated.

Astronaut surrounded by wires and mechanical devices within the space station. He’s wearing blue latex gloves while handling a transparent flat device in his right hand and holding onto a rectangular metal frame attached to the wall.

Canadian Space Agency (CSA) astronaut David Saint-Jacques removes the APEX-05 Petri Plate from the FIR/LMM (Fluids Integrated Rack/Light Microscopy Module). The Spaceflight-Induced Hypoxic/ROS Signaling (APEX-05) investigation grows different wild and mutant varieties of Arabidopsis thaliana, to understand how their genetic and molecular stress response systems work in space.

Lit in fuchsia light, an array of white plastic tubes in the shape of four-point stars stand in rows next to each other. Slid between these tubes are two square dishes. These dishes are transparent on one side and white on the other. Through the transparent side are two black circles, one on each of the top corners.

The APEX-05 Petri Plate in the Veggie facility onboard the International Space Station (ISS). The Spaceflight-Induced Hypoxic/ROS Signaling (APEX-05) investigation grows different wild and mutant varieties of Arabidopsis thaliana, to understand how their genetic and molecular stress response systems work in space.

Experiment Description

The Spaceflight-induced Hypoxic/ROS Signaling (APEX-05) Investigation compares wild-type plants grown on the International Space Station (ISS) with mutants defective in the gene CAX2 and in the ROS producing gene RBOHD. Plants are grown in the Veggie facility onboard the ISS chemically fixed, and then frozen for return to Earth. The levels of all the plant genes are to be determined upon return and compared to control samples grown on Earth.

Space Applications

Plants are likely to be a major component of bio-regenerative life support strategies for long-term space missions, providing food, and contributing to air and water purification. Additionally, plants provide significant psychological support for crew on long duration missions but exhibit a range of stress responses in spaceflight. These underlying stresses and the response systems, however, are still not fully understood. The APEX-05 investigation seeks to provide scientists with a better understanding of how plants change and adapt to the unique stresses of spaceflight. Results may also show whether genetic engineering of plants can be utilized to reduce some spaceflight-related stress responses.

Earth Applications

The APEX-05 Investigation addresses how low oxygen sensing, and other response systems, operate in plants in microgravity. Similar low oxygen stress occurs naturally on Earth during events, such as flooding or intense microbial blooms in the soil. These types of events can have profound effects on plant productivity and can have important impacts on plants in both natural ecological systems and in agricultural settings. The results from this work can help provide a better understanding of how these events affect plant biology, and aid in the development of countermeasures through plant breeding or genetic engineering.