The possible involvement of polyamines (PAs) in the chilling tolerance of cucumber (Cucumis sativus L. cv Jinchun No. 3 and cv Suyo) was investigated. Plants with the first expanded leaves were exposed to 3 degrees C or 15 degrees C in the dark for 24 h (chilling), and then transferred to 28 degrees C/22 degrees C under a 12-h photoperiod for another 24 h (rewarming). Chilling-tolerant cv Jinch...

It has been indicated that photosystem I (PSI) is susceptible to chilling-light stress in tobacco leaves, but the effect of growth light intensity on chilling-induced PSI photoinhibition in tobacco is unclear. We examined the effects of chilling temperature (4°C) associated with moderate light intensity (300 μmol photons m(-2) s(-1)) on the activities of PSI and photosystem II (PSII) in leaves ...

Rice (Oryza sativa L.) is often exposed to cool temperatures during spring planting in temperate climates. A better understanding of genetic pathways regulating chilling tolerance will enable breeders to develop varieties with improved tolerance during germination and young seedling stages. To dissect chilling tolerance, five assays were developed; one assay for the germination stage, one assay...

Chilling at 4 degrees C in the dark induced lipid degradation in cucumber (Cucumis sativa L.) fruit upon rewarming at 14 degrees C. Rates of ethane evolution by fruits rewarmed after 3 days of chilling were up to four-fold higher than those evolved by unchilled (14 degrees C) fruits (0.02-0.05 picomoles gram fresh weight(-1) hour(-1)). This potentiation of lipid peroxidation occurred prior to i...

Experiments comparing the photosynthetic responses of a chillingresistant species (Pisum sativum L. cv Alaska) and a chiHling-sensitive species (Cucumis sativus L. cv Ashley) have shown that cucumber photosynthesis is adversely affected by chilling temperatures in the light, while pea photosynthesis is not inhibited by chilling in the light. To further investigate the site ofthe differential re...

The activities of catalase, peroxidase, indoleacetic acid (IAA) oxidase and peroxide levels in cucumber plants during and after chilling were determined. During 96 hours at 5 C and 85% relative humidity, catalase activity declined, IAA oxidase activity increased, and peroxide concentrations increased. Peroxidase activity was not affected by chilling. When chilled plants were returned to 25 C to...

Eastern black walnut (Juglans nigra L.) is used as a rootstock for the Persian walnut (Juglans regia L.) in some parts of the world and also has an important role in forestry and wood industry. Due to the deep physiological dormancy, the seed often shows an inconsistent or low germination percentage, making establishment difficult. This experiment was carried out as a completely randomized desi...

Exposure to a chilling temperature of 2.5 degrees C for 96 h inhibited the subsequent growth of cucumber seedling radicles at 25 degrees C by 92%. Exposing seedling with 5 +/- 1 mm long radicles to acetaldehyde vapour (275 micro l l(-1)) or to an aqueous ethanol solution (0.6 M) for 2 h, or to 45 degrees C for 10 min before chilling, increased chilling tolerance so that the chilling treatment r...

Chilling at 2.5 C accelerated the synthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) and C(2)H(4) production in cucumber fruit. Skin tissue contained higher levels of ACC and was more sensitive to chilling than was cortex tissue. Accumulation of ACC in chilled tissue was detected after 1 day of chilling and remained elevated even after C(2)H(4) production started to decline. These data su...

Microbiological sampling of processed broiler carcasses often relies on the technique of whole-carcass rinsing; however, the rinse sampling is sometimes done immediately after immersion chilling and sometimes as long as 24 h after immersion chilling. To test whether carcass rinses done immediately after chilling can be compared with rinses 24 h after chilling, 20 whole broiler carcasses exiting...