Dong, C. H.; Zolman, B. K.; Bartel, B.; Lee, B.; Stevenson, B.; Agarwal, M.; Zhu, J. K.
Author Affiliation :
Department of Botany and Plant Science, 2150 Batchelor Hall, University of California at Riverside, Riverside, CA 92521, USA.
Author Email :
Bressan, R.; Bohnert, H.; Zhu, J. K.
To study cold signaling, we screened for Arabidopsis mutants with altered cold-induced transcription of a firefly luciferase reporter gene driven by the CBF3 promoter (CBF3-LUC). One mutant, chy1-10, displayed reduced cold-induction of CBF3-LUC luminescence. RNA gel blot analysis revealed that expression of endogenous CBFs also was reduced in the chy1 mutant. chy1-10 mutant plants are more sensitive to freezing treatment than wild-type after cold acclimation. Both the wild-type and chy1 mutant plants are sensitive to darkness-induced starvation at warm temperatures, although chy1 plants are slightly more sensitive. This dark-sensitivity is suppressed by cold temperature in the wild-type but not in chy1. Constitutive CBF3 expression partially rescues the sensitivity of chy1-10 plants to dark treatment in the cold. The chy1 mutant accumulates higher levels of reactive oxygen species, and application of hydrogen peroxide can reduce cold-induction of CBF3-LUC in wild-type. Map-based cloning of the gene defective in the mutant revealed a nonsense mutation in CHY1, which encodes a peroxisomal β-hydroxyisobutyryl (HIBYL)-CoA hydrolase needed for valine catabolism and fatty acid β-oxidation. Our results suggest a role for peroxisomal metabolism in cold stress signaling, and plant tolerance to cold stress and darkness-induced starvation.
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Oxford University Press
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Indexing terms for this abstract:
Organism descriptor(s) :
Arabidopsis thaliana, Brassicales
cold tolerance, dark adaptation, gene expression, genes, genetic regulation, light relations, metabolism, mutants, mutations, signal transduction
Broader term(s) :
Arabidopsis, Brassicaceae, Brassicales, eudicots, angiosperms, Spermatophyta, plants, eukaryotes