Chilling sensitive

A shift in temperature from 38 to 22 °C leads to desaturation of fatty acids in Anabaena variabilis [110], resulting in control of the fluidity of the plasma membrane. Mutants have been isolated in Synechocystis PCC 6803 that were defective in desaturation of fatty acids, and the growth rate of one of these mutants was much lower than that of the wild-type at 22 °C [112]. It turned out that the mutant strain had a mutation in the gene desA, and when the wild-type allele was introduced into the chilling-sensitive cyanobacterium Anacystis nidulans, it resulted in increasing the tolerance of that strain to low temperature [113]. These experiments nicely demonstrate the existence of a mechanism of adaptation to low temperature in a chilling-tolerant cyanobacterium. 

Murata, N., Nishizawa, O.-I., Higashi, S., Hayashi, H., Tasaka, Y. and Nishida, I. (1992) Genetically engineered alteration in the chilling sensitivity of plants. Nature, 356, 710-713. 

Some horticultural crops such as sweet potatoes, bananas, and pineapples can suffer from chilling injury at low temperatures (Lee and Kader 2000). Chilling injury causes accelerated losses in ascorbic acid content of chilling-sensitive crops. Destruction of ascorbic acid can occur before development of any visible symptoms of chilling injury (Lee and Kader 2000). 

Squash such as courgette (zucchini) and cucumber is a chill-sensitive commodity. Exposure to chilling temperatures causes loss of membrane integrity and water redistribution from the cell to the intercellular space. Visible injury symptoms such as surface pitting and dark watery patches eventually develop. Early detection of chill injury is important in order to ascertain the necessity and correct timing of treatments such as heat shock, that can reverse the condition. However, delaying treatment to the point where visible symptoms appear is too late for reversal. 

Galactolipase Wild tomato species Higher activity in chilling-sensitive species Gemel et at., 1988... 

Hugly, S., McCourt, P., Browse, J., Patterson, G.W. Somerville, C. (1990). A chilling sensitive mutant of Arabidopsis with altered steryl-ester metabolism. Plant Physiology 93, 1053-62. 

King, A.I., Joyce, D.C. Reid, M.S. (1988). Role of carbohydrates in diurnal chilling sensitivity of tomato seedlings. Plant Physiology 86, 764-8. 

Roughan, P.G. (1985). Phosphatidylglycerol and chilling sensitivity in plants. Plant Physiology 77, 740-6. 

Arrhenius plots have been used to identify processes that change markedly over the range of temperatures that injure chilling-sensitive plants,... 

Pytkowicz, R.M. 1979. Activity Coefficients in Electrolyte Solutions. CRC Press, Cleveland, OH. Raison, J.K., and Chapman, E.A. 1976. Membrane phase changes in chilling-sensitive Vigna radiata and their significance to growth. Aust. I. Plant Physiol. 3 291-299. 

Another topic is the protection of perishable fruits, vegetables, potted plants, and cut flowers. Many tropical fruits and vegetables are chill sensitive and cannot be transported or stored under low-temperature conditions. Other means for delaying deterioration are therefore needed. 

Chloroplasts are the first and the most severely affected organelles by chill [32]. The thylakoids swell and distort, starch granules disappear, and a peripheral reticulum appears. Chilling also leads to cytoplasmic acidification in chill-sensitive plants [38]. As the temperature drops below 0°C, the difference in concentration between intracellular (symplast) and extracellular fluids... 

Kawamura Y. Chilling induces a decrease in pyrophosphate-dependent H+-accumu-lation associated with a ApHvac-stat in mung bean, a chill-sensitive plant. Plant, Cell Environment 2008 31(3) 288-300. 

They suggested that demethylation of the pectin by pectinmethyl-esterase resulted in a more rigid cell wall structure, and that this deesterification may be a common characteristic of chilling-sensitive plants ( ). ... 

When beer is refrigerated, chill-sensitive proteins precipitate, causing a haze. Activated carbon is utilized as a supplementary purifier to remove any undesirable proteins not removed by enzymes. An advocated dosage is 5-6 pounds of carbon per 100 barrels of beer.35... 

Bjorkman, 1995) to -hi5 °C in a chilling-sensitive mangrove species and cotton (Gilmore and Bjorkman,... 

Cultivars differ in chilling tolerance. Chilling tolerance in rice cultivars was closely linked to the cold stability of CAT and APX when chilling sensitive cultivar K-sen 4 was compared to tolerant cultivar Dunghan Ahali during a 7-day exposure to 5°C (Saruyama and Tanida 1995). Often, the less-tolerant cultivars benefit more... 

In this study, attached leaves of chilling-sensitive pumpkin were treated in high light at room temperature or at 1°C, where diffusion-and enzyme-dependent repair processes are at a minimum. 

The differences in the inhibition of PSII and WC electron transfer activities (H2O to PPBQ and H2O to MV, respectively) support the view that only B-PSII (PSII ) is photoinhibited. The results also support the hypothesis (3), that a repair process replaces photoinhibited PSIIq centers by non-B-PSII and synthetizes new non-B-PSII. In the chilling sensitive pumpkin, this process seems to function at RT but not at 1°C. The difference between photoinhibition occurring simultaneously with an active repair process and inhibition without repair is best illustrated by plotting the ratio of WC activity to PPBQ reduction as a function of WC activity. Fig. 3. compares experimantal results with theoretical curves, obtained by simulating competition between photoinhibition and repair. The repair process was assumed to include both replacement of photoinhibited a-centers by non-B-PSII and synthesis of new non-B-PSII (cf. Fig. 3. for details). The upper curve is only schematic, because actual rates of replacement and synthesis in the different PPFD s are unknown. Anyway, inhibition of WC-activity is expected to be slower than inhibition of PPBQ-activity always, when the rates of replacement and synthesis are comparable to the rate of photoinhibition, and when the inhibition is not very severe. The exact shape of the lower curve (without repair) depends only on the proportion of non-B-PSII. 

Although experimental points do not completely fit the rough simulation, it is clear that the rates of the repair process form the basis of the observed differences in photoinhibition of PSII at RT and at 1 C in the chilling sensitive pumpkin. 

CHILLING-INDUCED ALTERATIONS IN THE PHOTOSYNTHETIC CAPACITY OF CHILLING-TOLERANT AND CHILLING-SENSITIVE CULTIVARS OF ZEA HAYS... 

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