ASGSB 2003 Annual Meeting Abstracts
THE INTERSECTION BETWEEN THE RED LIGHT AND GRAVITY RESPONSE MECHANISM IN PLANT
Sheppy, A. Mengucci, TJ White, K. Findlay, K. Oh, M. Ivanchenko, and T.L.
The response of higher plants to gravity is regulated by integrated
interactions among environmental and endogenous signals. Interactions between
light and the gravitropic response have long been recognized, but the
underlying mechanism is poorly understood. Fundamental knowledge in this
field will allow effective application of light to improve plant growth in
space, essential biological knowledge to support NASA’s goals for
long-duration human presence and exploration in space. The lazy-2
mutant of tomato demonstrates the unique phenomenon of reversed gravicurvature
of plant shoots upon exposure to red light. Our objective is to utilize the
lazy-2 lesion to elucidate the molecular mechanisms of light regulation
of the gravitational set-point angle. Our strategy is based on 1) generation
of transgenic tomato plants carrying auxin-responsive promoter:reporter
constructs to study changes in hormone transport and sensitivity in response
to gravity and red light, 2) identification of molecular components of the
gravity and light signal transduction pathway via global expression profiling,
and 3) cloning of the Lazy-2 gene to identify its role in light
regulation of the gravitropic response.
(Supported by NASA Fundamental Space Biology Division: NAG2-1593).
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