Two mutants of Arabidopsis thaliana that become chlorotic in atmospheres enriched with CO2 |
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Authors: | N N ARTUS MSU-DOE |
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Institution: | Plant Research Lab and Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, U.S.A. |
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Abstract: | Abstract. Two nonallelic, nuclear recessive mutants of Arabidopsis thaliana (L.) Heynh. which become chlorotic when grown in an atmosphere enriched to 20000 cm3 CO2 m-3 have been isolated. For one of the mutants, chlorosis begins at the veins and gradually spreads to the interveinal regions. A minimum photon flux density of ca 50 μmol m-2 s-1 is required for this response. For the other mutant, the yellowing is independent of the light intensity and begins at the basal regions of the leaves and spreads to the tips. The injurious effects of CO2 seem to be restricted to photosynthetic tissues, since root elongation and callus growth were not inhibited by a high atmospheric CO2 concentration for either mutant. Neither mutant became chlorotic in a low O2 atmosphere that suppressed photorespiration as effectively as the elevated CO2 does. Thus, the mutations do not impose a requirement for photorespiration. The possibilities that the high CO2-sensitive phenotypes are caused by an effect of CO2 in stomata, on ethylene synthesis, or on mineral uptake are discussed but are considered unlikely. |
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Keywords: | Arabidopsis thaliana carbon dioxide enrichment chlorosis mutants |
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