ASGSB 2003 Annual Meeting Abstracts


Cytological and molecular studies on Arabidopsis seed development under normoxic and hypoxic conditions. L. Zhao and C.D. Chase. Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611-0690.

   Hypoxia potentially affects seed development during space flight. Arabidopsis seed development is aborted under hypoxia conditions (Porterfield et al., 1999. Can. J. Bot., 77: 1439). One consequence of microgravity is a lack of convective air circulation. This can result in the exposure of plants to atmospheric stresses including excess ethylene, insufficient carbon dioxide, and hypoxia (Paul and Ferl, 2002. J. Plant Growth Regul., 21:166). Because Arabidopsis plants evolve ethylene secondary to hypoxia (Peng et al., Plant Physiol. 126: 742), it is not clear whether lack of oxygen and/or the presence of ethylene arrests seed development. To study seed development under hypoxia, both wild-type (Columbia) and ethylene insensitive mutants (ein2-1) of Arabidopsis thaliana were grown to seed set under normoxic (21.5% O2, 0.035% CO2, balance N2) or hypoxic (3% O2, 0.035% CO2, balance N2) conditions. We employ both light microscopy and electron microscopy to examine structures of the developing ovules and stomata under the normoxic and hypoxic conditions. Mitochondrial protein accumulation in both wild type and ethylene insensitive mutants is analyzed by SDS polyacrylamide gel electrophoresis immunoblotting. In addition, the expression of hypoxia-response genes is analyzed by RNA blot hybridization.

(Supported by NASA: NA610-316)     


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