An improved conductivity method for the measurement of frost hardiness

Zhang, M. I. N.; Willison, J. H. M.

doi:10.1139/b87-095

Cited by 52 publications

(49 citation statements)

References 8 publications

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“…The tubes were then autoclaved, and the conductivity re-measured. The LT 50 (lethal temperature at which 50% of the tissue is killed) was then derived from these data according to the method of Zhang and Willison (1987). Percent injury was determined using the formula:…”

Section: Ion Leakage Assaysmentioning

confidence: 99%

Ectopic expression of a novel peach (Prunus persica) CBF transcription factor in apple (Malus × domestica) results in short-day induced dormancy and increased cold hardiness

Wisniewski

Norelli

Bassett

et al. 2011

Planta

179

133

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Low, non-freezing temperatures and/or short daylength (SD) regulates cold acclimation and dormancy in fruit trees. Regarding cold acclimation, C-repeat binding factor (CBF/DREB) transcriptional activator genes have the well-documented ability to induce the expression of a suite of genes associated with increased cold tolerance. We isolated a full-length cDNA of a peach CBF gene, designated PpCBF1 (GenBank Accession HM992943), and constitutively expressed it using an enhanced 35S promoter in apple. Unexpectedly, constitutive overexpression of the PpCBF1 in apple resulted in strong sensitivity to short daylength. Growth cessation and leaf senescence were induced in transgenic lines exposed to SD and optimal growth temperatures of 25°C over a 4-week period. Following 1-4 weeks of SD and 25°C trees were returned to LD and 25°C in the greenhouse. Control (untransformed) plants continued to grow while transgenic lines receiving two or more weeks of SD remained dormant and began to drop leaves. Constitutive overexpression of the PpCBF1 in apple resulted in a 4-6°C increase in freezing tolerance in both the non-acclimated and acclimated states, respectively, compared with untransformed M.26 trees. This is the first instance that constitutive overexpression of a CBF gene has resulted in SD-induction of dormancy and to our knowledge the first time apple has been shown to strongly respond to short daylength as a result of the insertion of a transgene.

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Section: Ion Leakage Assaysmentioning

confidence: 99%

Ectopic expression of a novel peach (Prunus persica) CBF transcription factor in apple (Malus × domestica) results in short-day induced dormancy and increased cold hardiness

Wisniewski

Norelli

Bassett

et al. 2011

Planta

179

133

View full text Add to dashboard Cite

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“…Different segments from 1-year-old twigs were used at each sampling date to assess frost hardiness by the electrolyte leakage method (Zhang and Willison 1987;Sutinen et al 1992). In 2007-2008, stems were sampled every month from 5 December through budburst in lowland location.…”

Section: Frost Hardiness Testsmentioning

confidence: 99%

“…Relative electrolytic leakage (REL) was calculated as (C 1 /C 2 )*100 as described in Zhang and Willison (1987). We assumed the following relationship between REL and percentage of cellular lyses (L) for each sample:…”

Section: Frost Hardiness Testsmentioning

confidence: 99%

Are budburst dates, dormancy and cold acclimation in walnut trees (Juglans regia L.) under mainly genotypic or environmental control?

et al. 2011

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As observed for most stresses, tree frost resistance can be split into two main processes: avoidance and tolerance. Avoidance of freezing is achieved by introducing species only in the climatic context in which the probability of freezing events is very low for the sensitive stages of buds or stems; i.e., when good synchronism exists between the annual cycle and the critical climatic periods. Buds become able to grow only after chilling requirements have been satisfied (endodormancy released) during winter; they subsequently break after heat requirements have been completed (end of ecodormancy) in early spring. Actually, this period is often subject to more or less severe freezing events. Trees are also able to adjust their freezing tolerance by increasing their capacity of extracellular freezing and decreasing the possibility of intracellular freezing through the process of frost acclimation. Both freezing resistance processes (avoidance and tolerance) are environmentally driven (by photoperiod and temperature), but there are also genotypic effects among species or cultivars. Here, we evaluated the degree to which differences in dormancy release and frost acclimation were related to environmental and genetic influences by comparing trees growing in common garden conditions. This investigation was carried out for two winters in lowland and mountain locations on different walnut genotypes differing significantly for budburst dates. Chilling requirement for endodormancy release and heat requirement during ecodormancy were evaluated in all situations. In addition, frost acclimation was assessed by the electrolyte leakage method on stems from the same trees before leaf fall through budburst. No significant differences were observed in chilling requirements among genotypes. Moreover, frost acclimation dynamics were similar between genotypes or locations when expressed depending on chilling units accumulated since 15 September as a time basis instead of Julian day. The only exception was for maximal frost hardiness observed during winter with the timber-oriented being significantly more resistant than fruit-oriented genotypes. Heat requirement was significantly different among genotypes. Thus, growth was significantly faster in fruit-oriented than in wood-oriented genotypes. Furthermore, among wood-oriented genotypes, differences in growth rate were observed only at cold temperatures. Frost acclimation changes differed significantly between fruit- and wood- walnuts from January through budburst. In conclusion, from September through January, the acclimation dynamic was driven mainly by environmental factors whereas from January through budburst a significant genotype effect was identified in both frost tolerance and avoidance processes.

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“…Electrolyte leakage was measured after 14 h of incubation with different carbohydrates at a 0.15 M concentration according to the method of Zhang and Willison (1987) with some modifications. Fifty milligrams of freshly filtered cells was rinsed three times with ultra-pure water, resuspended in a 5-mL tube with 500 pL of ultra-pure water, and then placed in a cryostat at 4°C and subjected to the same cooling program as for the TTC method.…”

Section: Electrolyte Leakage Measurement After a Cooling Programmentioning

confidence: 99%

Enrichment in Specific Soluble Sugars of Two Eucalyptus Cell-Suspension Cultures by Various Treatments Enhances Their Frost Tolerance via a Noncolligative Mechanism

et al. 1997

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A cell-suspension culture obtained from the hybrid Eucalyptus gunnii/Eucalyptus globulus was hardened by exposure to lower temperatures, whereas in the same conditions cells from a hybrid with a more frost-sensitive genotype, Eucalyptus cypellocarpa/ Eucalyptus globulus, were not able to acclimate. During the cold exposure the resistant cells accumulated soluble sugars, in particular fructose and sucrose, with a limited increase i n cell osmolality.I n contrast, the cell suspension that was unable to acclimate did not accumulate soluble sugars in response to the same cold treatment.To an extent similar to that induced after a cold acclimation, frost-hardiness of the cells increased after a 14-h incubation with specific soluble sugars such as sucrose, raffinose, fructose, and mannitol. Such hardening was also observed for long-term cultures in mannitol-enriched medium. This cryoprotective effect of sugars without exposure t o lower temperatures was observed i n both the resistant and the sensitive genotypes. Mannitol was one of the most efficient carbohydrates for the cryoprotection of eucalyptus. l h e best hardiness (a 2.7-fold increase in relative freezing tolerance) was obtained for the resistant cells by the cumulative effect of cold-induced acclimation and mannitol treatment. This positive effect of certain sugars on eucalyptus freezing tolerance was not colligative, since it was independent of osmolality and total sugar content.Many plants become more resistant to freezing temperatures when first exposed to low, nonfreezing temperatures, a process known as cold acclimation or cold hardening. Cell-suspension cultures derived from plants capable of cold acclimation can also be hardened to withstand freezing, but few data are available on low-temperatureinduced cold acclimation in cell suspensions derived from woody plants (Hellergren, 1983;Tremblay et al., 1992;Arora and Wisniewski, 1995;Leborgne et al., 1995b).Biochemical changes associated with cold acclimation include alterations in the concentrations of a wide range of metabolites, including sugars (Hallgren and Oquist, 1990 These complex changes indicate that cellular metabolism undergoes considerable modifications during acclimation, but the cause/effect relationships have not been clearly established. Carbohydrates that are compatible solutes with a demonstrated cryoprotectant activity are often reported to accumulate at low temperatures (acclimation). These include oligosaccharides such as Suc and raffinose, and polyols such as sorbitol and mannitol. Carbohydrates seem to function in two ways that are often difficult to distinguish: osmotic adjustment (a colligative effect) and cryoprotection of cellular structures.Eucalyptus, an evergreen woody plant exhibiting excellent productivity, good fiber quality, and high pulp yield, is grown extensively around the world, mostly for pulp making. However, a major limitation to the expansion of these plantations is the relatively high frost sensitivity of some species. For example, for Eucalyptus globulus, one...

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An improved conductivity method for the measurement of frost hardiness

Cited by 52 publications

References 8 publications

Ectopic expression of a novel peach (Prunus persica) CBF transcription factor in apple (Malus × domestica) results in short-day induced dormancy and increased cold hardiness

Ectopic expression of a novel peach (Prunus persica) CBF transcription factor in apple (Malus × domestica) results in short-day induced dormancy and increased cold hardiness

Are budburst dates, dormancy and cold acclimation in walnut trees (Juglans regia L.) under mainly genotypic or environmental control?

Enrichment in Specific Soluble Sugars of Two Eucalyptus Cell-Suspension Cultures by Various Treatments Enhances Their Frost Tolerance via a Noncolligative Mechanism

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