Oxygen‐mediated cold‐acclimation in cucumber (Cucumis sativus) seedlings

Abstract

Cold acclimation of etiolated cucumber seedlings, consisting of cooling at 12 degrees C for 48 h followed by a warming period at 25 degrees C, led to tolerance to subsequent chilling at 2 degrees C. Tolerance, as evidenced by freedom from chilling injury and continued growth, developed during the warming period in a time-course manner for 12 h but decreased with prolonged warming. A similar increase and subsequent decrease was also observed in the content of palmitic, linoleic and linolenic acids in total lipid fraction from cucumber hypocotyl tissue. During the warming period supra-ambient oxygen stimulated, whereas subambient oxygen inhibited, the increase in fatty acid content as well as development of chilling tolerance. A strong correlation between oxygen-mediated changes in fatty acid content and associated development of cold tolerance suggests that both these processes are interrelated. Cold acclimation, but not cold stress, led to an increase followed by a decrease in CO2 evolution suggesting that a respiratory upsurge is yet another feature of cold acclimation in cucumbers.

Decrease in Fruit Moisture Content Heralds and Might Launch the Onset of Ripening Processes

“…A temperature regime for cold stress and acclimation was adopted from a protocol by Erez and others (2002) and consisted of holding ethylene‐mutant tomato fruit for 60 h at 12 °C and next at 23 °C for up to 8 d for cold acclimation.…”

Relationships of Cold Acclimation and Antioxidative Enzymes with Chilling Tolerance in Cucumber (Cucumis sativus L.)

“…), to low temperature reduces chilling injury (Anderson et al, 1995;Venema et al, 2000). Although mechanisms of chilling injury and tolerance have been studied in cucumber plants (Erez et al, 2002;Reyes and Jennings, 1994;Terashima et al, 1994), little is known about the role of antioxidative enzymes in chilling tolerance.…”

COLD‐CONDITIONING TREATMENT REDUCES CHILLING INJURY IN MEXICAN LIMES (CITRUS AURANTIFOLIA S.) STORED AT DIFFERENT TEMPERATURES

“…Conditioning of sweet peppers at 10C for 5 or 10 days prior to storage at 0C decreased CI (McColloch 1962). Also, by keeping zucchini squash at 10 or 15C for 2 days, symptoms of CI during the storage at 2.5 or 5C were delayed (Kramer and Wang 1989), and cold acclimation of cucumber seedlings at 12C for 48 h led to tolerance to subsequent chilling at 2C (Erez et al. 2002).…”