ASGSB 2003 Annual Meeting Abstracts


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THE INTERSECTION BETWEEN THE RED LIGHT AND GRAVITY RESPONSE MECHANISM IN PLANT SHOOTS.  W. Sheppy, A. Mengucci, TJ White, K. Findlay, K. Oh, M. Ivanchenko, and T.L. Lomax. 

   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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