Constitutive expression of the cold-regulated Arabidopsis thaliana COR15a gene affects both chloroplast and protoplast freezing tolerance.

Cold acclimation in plants is associated with the expression of COR (cold-regulated) genes that encode polypeptides of unknown function. It has been widely speculated that products of these genes might have roles in freezing tolerance. Here we provide direct evidence in support of this hypothesis. We show that constitutive expression of COR15a, a cold-regulated gene of Arabidopsis thaliana that encodes a chloroplast-targeted polypeptide, enhances the in vivo freezing tolerance of chloroplasts in nonacclimated plants by almost 2 degrees C, nearly one-third of the increase that occurs upon cold acclimation of wild-type plants. Significantly, constitutive expression of COR15a also affects the in vitro freezing tolerance of protoplasts. At temperatures between -5 and -8 degrees C, the survival of protoplasts isolated from leaves of nonacclimated transgenic plants expressing COR15a was greater than that of protoplasts isolated from leaves of nonacclimated wild-type plants. At temperatures between -2 and -4 degrees C, constitutive expression of COR15a had a slight negative effect on survival. The implications of these data regarding possible modes of COR15a action are discussed.

[1]  S. Rothstein,et al.  Promoter cassettes, antibiotic-resistance genes, and vectors for plant transformation. , 1987, Gene.

[2]  Charles L. Guy,et al.  Cold Acclimation and Freezing Stress Tolerance: Role of Protein Metabolism , 1990 .

[3]  H. Towbin,et al.  Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. , 1979, Proceedings of the National Academy of Sciences of the United States of America.

[4]  S. J. Gilmour,et al.  Effects of COR6.6 and COR15am Polypeptides Encoded by COR (Cold-Regulated) Genes of Arabidopsis thaliana on the Freeze-Induced Fusion and Leakage of Liposomes , 1996, Plant physiology.

[5]  H. Sambrook.  Molecular cloning : a laboratory manual. Cold Spring Harbor, NY , 1989 .

[6]  C. Guy,et al.  Altered gene expression during cold acclimation of spinach. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[7]  M. Uemura,et al.  Cold Acclimation of Arabidopsis thaliana (Effect on Plasma Membrane Lipid Composition and Freeze-Induced Lesions) , 1995, Plant physiology.

[8]  S. J. Gilmour,et al.  Effects of COR6.6 and COR15am Polypeptides Encoded by COR (Cold-Regulated) Genes of Arabidopsis thaliana on Dehydration-Induced Phase Transitions of Phospholipid Membranes , 1996, Plant physiology.

[9]  H. Schägger,et al.  Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa. , 1987, Analytical biochemistry.

[10]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[11]  M. Thomashow,et al.  A cold-regulated Arabidopsis gene encodes a polypeptide having potent cryoprotective activity. , 1992, Biochemical and biophysical research communications.

[12]  D. Bartels,et al.  Molecular cloning and characterization of cold-regulated genes in barley. , 1990, Plant physiology.

[13]  M. Van Montagu,et al.  Agrobacterium tumefaciens-mediated transformation of Arabidopsis thaliana root explants by using kanamycin selection. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[14]  Warren L. Butler,et al.  Energy Distribution in the Photochemical Apparatus of Photosynthesis , 1978 .

[15]  D. Siminovitch,et al.  Drought and freezing tolerance and adaptation in plants: some evidence of near equivalences. , 1982, Cryobiology.

[16]  R. Dhindsa,et al.  Molecular cloning and relationship to freezing tolerance of cold-acclimation-specific genes of alfalfa. , 1989, Plant physiology.

[17]  M. Thomashow,et al.  Cold acclimation in Arabidopsis and wheat : a response associated with expression of related genes encoding ;boiling-stable' polypeptides. , 1990, Plant physiology.

[18]  S. J. Gilmour,et al.  Cold Acclimation in Arabidopsis thaliana. , 1988, Plant physiology.

[19]  U. Heber,et al.  Cryoprotective leaf proteins. , 1975, Biochimica et biophysica acta.

[20]  T. White,et al.  Characterization of Three Related Low-Temperature-Regulated cDNAs from Winter Brassica napus , 1993, Plant physiology.

[21]  L. Vézina,et al.  New Cold- and Drought-Regulated Gene from Medicago sativa , 1993, Plant physiology.

[22]  E. Gotschlich,et al.  A rapid, sensitive method for detection of alkaline phosphatase-conjugated anti-antibody on Western blots. , 1984, Analytical biochemistry.

[23]  M. Thomashow.  Molecular Genetics of Cold Acclimation in Higher Plants , 1990 .

[24]  M. Uemura,et al.  Effect of cold acclimation on the incidence of two forms of freezing injury in protoplasts isolated from rye leaves. , 1989, Plant physiology.

[25]  M. Thomashow,et al.  DNA Sequence Analysis of a Complementary DNA for Cold-Regulated Arabidopsis Gene cor15 and Characterization of the COR 15 Polypeptide. , 1992, Plant physiology.

[26]  J. Widholm.  The use of fluorescein diacetate and phenosafranine for determining viability of cultured plant cells. , 1972, Stain technology.

[27]  G. Krause,et al.  Chlorophyll Fluorescence and Photosynthesis: The Basics , 1991 .

[28]  W. Cox.  Interrelations between Environmental Factors and Freezing Resistance of Cabbage Leaves. , 1976, Plant physiology.