Gene induction and repression by salt treatment in roots of the salinity-sensitive Chinese Spring wheat and the salinity-tolerant Chinese Spring x Elytrigia elongata amphiploid.
An artificial amphiploid from a cross between salinity-sensitive bread wheat cultivar Chinese Spring and highly tolerant Elytrigia elongata (Host) Nevski (= Agropyron elongatum Host) shows enhanced salinity tolerance relative to Chinese Spring. Poly(A)(+) RNA was isolated from roots, expanding leaves, and old leaves from amphiploid and Chinese Spring plants prior to and after acclimation to high levels of NaCl in solution cultures. Two-dimensional gel electrophoresis of the in vitro translation products was used to compare these mRNA populations. The amphiploid had 10 mRNA species induced or enhanced and 8 species repressed in root tissue during acclimation to saline growth conditions. These 18 transcripts affected by salt treatment were also detected in wheat roots, but only 4 of these were similarly regulated. In Chinese Spring the acclimation to saline stress resulted in a marked change in the level of expression of 34 transcripts in root tissue; of these, 26 were detected in the amphiploid and only 6 were regulated as in the amphiploid. No differences were seen in gene expression between salt-treated and control plants in leaves and meristematic crowns and unexpanded leaves of the amphiploid.
Department of Agronomy and Range Science, University of California, Davis, CA 95616.
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Gulick
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Dvorák