Cold-acclimation

Fourier Transform Infra Red Spectroscopy, Arrhenius plots of rate vs. temperature of a membrane-linked phenomenon) that biological membranes from nonhibemat-ing or cold acclimated animals show a phase transition around 12 °C to 17 °C. Thus, at useful cold storage temperatures, it is expected that the plasma membrane and membranes of the cellular organelles will be mostly in a gel or solid state. 

Guy, C.L., Niemi, K.J. Brambl, R. (1985). Altered gene expression during cold acclimation of spinach. Proceedings of the National Academy of Sciences, USA, 82, 3673-7. 

L Jansky, JS Hart. Cardiac output and organ blood flow in warm and cold-acclimated rats exposed to cold. Can J Physiol Pharmacol 46 653-659, 1968. 

It is known that ER changes from flattened cistemae to small vesicles during seasonal cold acclimation in mulberry cortical parenchyma cells... 

To identify the specialized features of the ER, we isolated the ER from mulberry cortical parenchyma cells every month from August to June. In this chapter, we described the method of isolation of ER from mulberry cortical parenchyma cells. At the end of this chapter, we show the results of our characterization of the protein component in ER during cold acclimation in mulberry cortical parenchyma cells. 

Yoshida S. Chemical and biophysical changes in the plasma membrane during cold acclimation of mulberry bark cells (Moms bombycis Koidz. cv Goroji). Plant Physiol 1984 76 257-265. 

Ukaji N, Kuwabara C, Takezawa D, Arakawa K, Yoshida S, Fujikawa S. Accumulation of small heat shock protein homologs in the endoplasmic reticulum of cortical parenchyma cells in mulberry in association with seasonal cold acclimation. Plant Physiol 1999 120 481-490. 

Phenolic compounds may be involved in plant responses to cold stress and in plant acclimation to low temperature. Acclimation of apple trees to cold climates was found to be associated with a seasonal accumulation of chlorogenic acid [102]. Strengthened frost tolerance in a variety of plants were attributed to thicker cell-wall lignification or suberization [102]. Thickening of cell walls and increased production of suberin-type lipids were observed in cold-acclimated winter rye leaves [103]. The presence of suberin in cell walls may favour membrane cell-wall adhesion, a major factor in the resistance of plant cells to freezing [104]. 

Leng P, Itamura H, Yamamura H, Deng XM. 2000. Anthocyanin accumulation in apple and peach shoots during cold acclimation. Sci Hortic 83 43-50. 

The subject of this chapter will be to summarise the biochemical and molecular changes which take place during the process of cold acclimation and the acquisition of freezing stress tolerance. We will discuss how polypeptides correlated with the acclimation process might play a role in increased cold tolerance and we will focus on recent results emerging from molecular studies. For further treatment of the subject the reader is referred to a number of recent review articles (Steponkus, 1984 Guy, 1990 Thomashow, 1990). The biochemistry and physiology of cold acclimation is described in detail by Levitt (1980). 

Before discussing the role of proteins in cold acclimation the physical effects caused by low temperature are briefly considered. A decrease of temperature leads to altered rates of enzymatic catalysis. Formation of hydrogen bonds and electrostatic interactions are thermodynamically more stable at a lower temperature whereas hydrophobic interactions are... 

In cereals the role of unsaturated fatty acids in cold acclimation has been demonstrated using a chemical (BASF 13-338) that reduces the linolenic acid content in polar lipids (St John et al., 1979). 

Analysis of changes in in-vivo- and m-v/tro-synthesised proteins is a very descriptive approach to understanding the phenomenon of cold acclimation and cold tolerance. For a functional analysis a molecular dissection of the process is required. This will allow investigators to determine the level (transcriptional/translational) at which the appearance of the new mRNAs is regulated, and the sequence information of the cold-regulated genes should point to the biochemical features of the encoded proteins. 

Many physiological studies established a correlation between cold acclimation and increasing ABA levels in plant tissues (Chen etal., 1983). Furthermore, exogenous ABA application can induce cold-hardening to the same degree as a low temperature treatment does (Chen Gusta, 1983) while plant species which do not show a hardening capacity at low temperature do not harden even after ABA treatment. 

Despite many studies on the effect of ABA on plant tissues there is no demonstration that ABA can regulate the level of enzyme activities and specially of those involved in cold acclimation. On the other hand, ABA certainly induces modifications in gene expression and many genes are modulated by ABA (Skriver Mundy, 1990). Indeed several in vivo protein-labelling and in vitro translation experiments have demonstrated that the level of certain proteins or mRNAs increased in response to both low temperature and exogenous ABA applications (Robertson et al., 1987 Mohapatra et al., 1988 Ling et al., 1989). 

Several of the cold-regulated genes isolated so far in Arabidopsis (Kurkela Franck, 1990 Hajela et al., 1990), alfalfa (Mohapatra et al., 1988) and barley (L. Cattivelli, unpublished data), show ABA-indu-cibility, but, at least in alfalfa and in barley, not all (Mohapatra et al., 1989 L. Cattivelli, unpublished data). These results support the hypothesis that although ABA is probably essential for hardening (in fact an ABA-deficient mutant does not cold-acclimate), it is not responsible for all the modifications induced during exposure of plants to low... 

The property of cold acclimation resulting in freezing tolerance has evolved in many temperate plants. The metabolic pathways of this complex process are mostly unknown. However, from recent work it is clear that gene activation is involved. By means of molecular biology some cold-regulated transcripts have been isolated and have become amenable to further analysis. The cDNA clones so far available probably correspond to only a small number of the transcripts which are affected by low temperature. One may therefore expect that the number of cDNA clones and genomic clones available for characterisation will increase in the near future. 

As pointed out in the introduction the cold acclimation capacity is a quantitative trait and work is just beginning to link such complex traits to molecular markers using restriction fragment length polymorphism (RFLP). Eventually, also, information about genes involved in environmental stress can be expected from these experiments. 

Charest, C. Phan, C.T. (1990). Cold acclimation of wheat (Triticum aestivum) properties of enzymes involved in proline metabolism. Physiologia Plantarum 80, 159-68. 

Chen, H.-H., Li, P.H. Brenner, M.L. (1983). Involvement of abscisic acid in potato cold acclimation. Plant Physiology 71, 362-5. 

Gilmour, S.J., Hajela, R.K. Thomashow, M.F. (1988). Cold acclimation in Arabidopsis thaliana. Plant Physiology 87, 745-50. 

Guy, C.L. (1990). Cold acclimation and freezing stress tolerance role of protein metabolism. Annual Review of Plant Physiology and Plant Molecular Biology 41, 187-223. 

Guy, C.L. Haskell, D. (1987). Induction of freezing tolerance in spinach is associated with the synthesis of cold acclimation induced proteins. Plant Physiology 84, 872-8. 

Lynch, D.V. Steponkus, P.L. (1987). Plasma membrane lipid alterations associated with cold acclimation of winter rye seedlings (Secale cereale L. cv. Puma). Plant Physiology 83, 761-7. 

Mohapatra, S.S., Poole, R.J. Dhindsa, R.S. (1987a). Changes in protein patterns and translatable messenger RNA populations during cold acclimation of alfalfa. Plant Physiology 84, 1172-6. 

Perras, M. Sarhan, F. (1989). Synthesis of freezing tolerance proteins in leaves, crown, and roots during cold acclimation of wheat. Plant Physiology 89, 577-85. 

Sarhan, F. Chevrier, N. (1985). Regulation of RNA synthesis by DNA-dependent RNA polymerases and RNases during cold acclimation in winter and spring wheat. Plant Physiology 78, 250-5. 

Steponkus, P.L. (1984). Role of the plasma membrane in freezing injury and cold acclimation. Annual Review of Plant Physiology 35, 543-84. 

Thomashow, M.F. (1990). Molecular genetics of cold acclimation in higher plants. Advances in Genetics 28, 99-131. 

Blier, P. and Guderley, H. (1988). Metabolic responses to cold acclimation in the swimming musculature of lake whitefish, Coregonus clupeaformis. Journal of Experimental Zoology 246,244—252. 

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