Create your own conference schedule! Click here for full instructions

Abstract Detail

Kaplan Memorial Lecture - John Kiss

How will space zucchini and Arabidopsis help get us to Mars?

Plants on Earth have evolved under the influence of a constant acceleration force of 9.81 m^.s^-2 (or 1-g). This persistent and ubiquitous physical force serves as an important input to shape plant growth, development, and morphology at all levels, from the molecular to the whole plant. Removing the gravitational acceleration in the conditions of free fall (or microgravity) that is achieved in orbiting spacecraft can have a profound effect on plant morphology and physiology. Studying plants in the microgravity environment also can provide novel insights into basic mechanisms of growth and development. For instance, we were able to investigate phototropism in plants grown in microgravity on the International Space Station (ISS) to explore the mechanisms of both blue-light and red-light-induced phototropism. A novel positive phototropic response to red light was observed in hypocotyls of seedlings that developed in microgravity. This response was not apparent in seedlings grown on Earth or in the 1-g control during the spaceflight. Although flowering plants are generally thought to lack red-light phototropism, our data suggest that at least some flowering plants may have retained a red-light sensory system for phototropism. Thus, this discovery may have important implications for understanding the evolution of light sensory systems. While plant growth and development in microgravity environments have been well characterized since the dawn of the space age, considerably less is known about plant growth in fractional or reduced gravity environments (less than the nominal 1-g on Earth). On the ISS, we were able to use a laboratory with a centrifuge which allows for the creation of gravity vectors to better characterize the interplay between gravitropism and phototropism. We examined the phototropic response to red and blue light in microgravity, 0.1-g, 0.3-g, and 1-g conditions, providing insight on how plant development may be affected on the Moon or Mars. Understanding how plants grow and develop in fractional gravity environment is an important step in successful habitation of other planets. Furthermore, fractional gravity studies are helpful for the determination of thresholds of gravity sensing. Plants will play an important role in Mars habitation in terms of bioregenerative life support systems. In addition, throughout the space age, plants have provided psychological support for the astronauts who will live in an environment isolated from Earth, so we also will see the importance of space zucchini for future missions to Mars and other planets.

1 - University of North Carolina - Greensboro, Biology, Greensboro, NC, 27402, USA

Keywords:
gravitropism
phototropism
space biology
Physiology
morphology
development.

Presentation Type: Special Presentations
Session: S5, Kaplan Memorial Lecture Reception
Location: Tucson E/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 4:00 PM
Number: S5001
Abstract ID:227
Candidate for Awards:None