Once the sensor and the reporter gene fragments are stitched together, Ferl uses a bacteria to move the newly-constructed gene into the plant. So, they've developed an exquisite variety of sensing mechanisms to monitor their surroundings and trigger appropriate responses to stressors. On Mars plants might adopt the same response to survive in the thin oxygen-poor atmosphere. Water on Mars will also be very scarce, and plants will need to conserve every bit. The leaves of all plants contain stomata, little holes that let gas molecules in and out.
Plants have the ability to open and close stomata as conditions demand.
The first wave of Martian plants envisioned by Ferl and his colleagues would sprout inside a very small and protected greenhouse. The greenhouse, he expects, could hold as many as 20 to 30 plants. As important as it is to know whether plants can actually grow on the Red Planet, this project also has a philosophical purpose, says Chris McKay, the principal investigator of the proposed Scout mission. And when this little plant grows on Mars, he believes, it's going to be a major awakening of our interest in our future in space.