A novel phototropic response to red light is revealed in microgravity

作者：Millar Katherine D L; Kumar Prem; Correll Melanie J; Mullen Jack L; Hangarter Roger P; Edelmann Richard E; Kiss John Z^*

来源：New Phytologist, 2010, 186(3): 648-656.

DOI：10.1111/j.1469-8137.2010.03211.x

• Arabidopsis thaliana
• European Modular Cultivation System (EMCS)
• International Space Station (ISS)
• microgravity
• phototropism
• phytochrome
• red light
• space biology

P>The aim of this study was to investigate phototropism in plants grown in microgravity conditions without the complications of a 1-g environment. Experiments performed on the International Space Station (ISS) were used to explore the mechanisms of both blue-light- and red-light-induced phototropism in plants.
This project utilized the European Modular Cultivation System (EMCS), which has environmental controls for plant growth as well as centrifuges for gravity treatments used as a 1-g control. Images captured from video tapes were used to analyze the growth, development, and curvature of Arabidopsis thaliana plants that developed from seed in space.
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 space flight. In addition, blue-light-based phototropism had a greater response in microgravity compared with the 1-g control.
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 in plants.

• 出版日期2010