scholarly journals Effect of Fall Fertilization on Freeze Resistance of Deciduous Versus Evergreen Azaleas

2010 ◽  
Vol 28 (4) ◽  
pp. 235-239
Author(s):  
Frank P. Henning ◽  
Timothy J. Smalley ◽  
Orville M. Lindstrom ◽  
John M. Ruter
Keyword(s):  
Nutrient Uptake ◽  
Cold Acclimation ◽  
Cold Hardiness ◽  
High Rate ◽  
Freeze Resistance ◽  
Flower Production ◽  
Moderate Rate

Abstract Plants that maintain their leaves throughout winter may respond differently to fall fertilization than deciduous plants. The effects of fall fertilization on cold hardiness, nutrient uptake, growth and flower production of evergreen versus deciduous azaleas were studied. Rhododendron canescens (Michx.) Sweet and R. × satsuki ‘Wakaebisu’ were grown in containers, outdoors in Athens, GA, under three fall fertigation regimes applied daily as 0.5 liter (0.13 gal) solutions containing: 1) 75 mg·liter−1 N from August 1 through September 29, 2) 75 mg·liter−1 N from August 1 through November 28, and 3) 125 mg·liter−1 N from August 1 through November 28. Stem freeze resistance was analyzed monthly November through March. Growth of azaleas that received 120 days of extended fertigation (August 1 through November 28) was not increased compared to azaleas that received 60 days of extended fertigation (August 1 through September 29). Growth of the two taxa did not differ in their response to fertilization treatments. The high rate of extended fertilization 125 mg·liter−1 N (from August 1 through November 28) reduced stem freeze resistance November through February, while the moderate rate of extended fertilization (75 mg·liter−1 N from August 1 through November 28) reduced azalea freeze resistance in December. Fall fertilization regimes did not produce differences in the timing of cold acclimation, or deacclimation of R. canescens and R. × satsuki. The high rate of extended fertilization promoted early budbreak of R. × satsuki and postponed flower budbreak of R. canescens. Flower production of R. canescens was not affected by fall fertilization, but the high rate of extended fertilization increased flower production of R. × satsuki compared to plants that received the moderate rate of fertilization 75 mg·liter−1 N from August 1 through September 29.

scholarly journals Physiological Research on Winter-hardiness: Deacclimation Resistance, Reacclimation Ability, Photoprotection Strategies, and a Cold Acclimation Protocol Design

HortScience ◽  
2011 ◽  
Vol 46 (8) ◽  
pp. 1070-1078 ◽  
Author(s):  
Rajeev Arora ◽  
Lisa J. Rowland
Keyword(s):  
Cold Acclimation ◽  
Freezing Tolerance ◽  
Cold Hardiness ◽  
Light Stress ◽  
Winter Hardiness ◽  
Field Conditions ◽  
Winter Survival ◽  
Cold Temperatures ◽  
Freeze Resistance ◽  
Woody Perennials

Freezing is a major environmental stress during an annual cycle of overwintering, temperate-zone perennials. The timing and extent of seasonal cold acclimation (development of freezing tolerance in the fall) and deacclimation (loss of acquired freezing tolerance in response to warm temperatures) are of critical importance for winter survival, particularly in view of the climate change, i.e., unpredictable extreme weather occurrences. For example, plants may acclimate inadequately if exposed to a milder fall climate and may be damaged by sudden frosts. Alternatively, they may deacclimate prematurely as a result of unseasonable, midwinter warm spells and be injured by the cold that follows. Efficient cold acclimation ability, high deacclimation resistance, and efficient reacclimation capacity are, therefore, important components of winter survival in overwintering perennials. These components should be evaluated separately for a successful breeding program focused on improving winter-hardiness. Another layer of complexity that should be carefully considered is that endodormant status (shallow versus deep) of the reproductive/vegetative apices can significantly impact these components of winter-hardiness. Winter survival, especially by woody evergreens, requires tolerance of light stress, which can result in photo-oxidative damage at cold temperatures when biochemistry of photosynthesis is somewhat compromised but light harvesting is unaffected. Accumulation of Elips (early light-induced proteins) in overwintering evergreens during winter represents a relatively novel strategy to cope with such light stress, and investigations on the precise cellular mechanism and genetic control of this strategy deserve research in the future. Investigations into the mechanisms for cold acclimation use laboratory-based, artificial acclimation protocols that often do not closely approximate conditions that plants are typically exposed to in nature. To draw meaningful conclusions about the biology of cold acclimation and ultimately improve freeze resistance under field conditions, one should also include in cold acclimation regimens parameters such as exposure to subfreezing temperatures and realistic diurnal temperature fluctuations and light levels to simulate natural conditions. One of the main objectives of this article is to highlight two areas of research that we believe are important in the context of plant cold-hardiness but, so far, have not received much attention. These are: 1) to understand the biology of deacclimation resistance and reacclimation capacity, two important components of freeze-stress resistance (winter-hardiness) in woody perennials; and 2) to investigate the cellular basis for various strategies used by broad-leaved evergreens for photoprotection during winter. Our emphasis, in this context, is on a family of proteins, called Elips. The second objective of this article is to draw attention of the cold-hardiness research community to the importance of using realistic cold acclimation protocols in controlled environments that will approximate natural/field conditions to be better able to draw meaningful conclusions about the biology of cold acclimation and ultimately improve freeze resistance. Results from our work with Rhododendron (deciduous azaleas and broad-leaved evergreens), blueberry, and that of other researchers are discussed to support these objectives.

scholarly journals Influences of Shading and Fall Fertilization on Fluorescence, Freeze Resistance, Flower Production and Growth of Rhododendron ×kurume ‘Pink Pearl’

2012 ◽  
Vol 30 (1) ◽  
pp. 28-34
Author(s):  
Frank P. Henning ◽  
Timothy J. Smalley ◽  
Orville M. Lindstrom ◽  
John M. Ruter
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
Fertilizer Application ◽  
High Rate ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Freeze Resistance ◽  
Time Period ◽  
Shade Cloth ◽  
Main Plot

We investigated the influences of fall fertilization and light intensity on photosynthesis and freeze resistance of Rhododendron ×kurume ‘Pink Pearl’, an evergreen azalea cultivar, grown outdoors in containers under nursery conditions. The study included two main-plot fall fertilization treatments: 1) 0.5 liter solution containing 75 mg·liter−1 N applied for 60 days from August 1 through September 29 and 2) 0.5 liter solution containing 125 mg·liter−1 N applied for 120 days from August 1 through November 28, and four subplot light intensity treatments 1) 100% ambient photon flux density (PPFD) from May 1, 2004, through May 1, 2005, 2) shade fabric rated to reduce PPFD by 50% from May 1 through September 30, 2004, followed by 100% PPFD from October 1, 2004, through May 1, 2005, 3) 100% PPFD from May 1 through September 30, 2004, followed by 50% PPFD from October 1, 2004, through May 1, 2005, and 4) 50% PPFD from May 1, 2004, through May 1, 2005. Fertilizer application and shade treatments did not interact in their effects on stem freeze resistance or the timing of anthesis. The high rate of extended fertigation (125 mg·liter−1 N applied August 1 through September 28) reduced freeze resistance of azalea stems and advanced anthesis by 4.9 days compared to plants that received moderate fertigation (75 mg·liter−1 N from August 1 through September 29). The high rate of extended fall fertigation failed to increase leaf or stem dry weight compared to plants that received the moderate rate of fertigation. Plants grown in 50% PPFD from May 1 through September 30 produced 163% more above ground dry weight compared to plants grown in 100% light during the same time period. The addition or removal of shade cloth beginning October 1 failed to enhance azalea stem freeze resistance compared to plants that were only exposed to 100 or 50% PPFD respectively. Shade treatments affected the chlorophyll fluorescence ratio (Fv · Fm−1) of leaves, but leaf fluorescence was unrelated to stem freeze resistance. Shade treatments affected azalea growth and photosynthetic stress, but shade neither interacted with fall fertilization to increase stem freeze resistance, nor had a biologically significant effect on stem freeze resistance.

Cold acclimation-recruited nonshivering thermogenesis: the Syrian hamster is not an exception

1995 ◽  
Vol 269 (4) ◽  
pp. R767-R774 ◽  
Author(s):  
A. Dicker ◽  
B. Cannon ◽  
J. Nedergaard
Keyword(s):  
Metabolic Rate ◽  
Cold Acclimation ◽  
Resting Metabolic Rate ◽  
High Rate ◽  
In Vivo Studies ◽  
Nonshivering Thermogenesis ◽  
Brown Adipose ◽  
Thermogenic Response

Biochemical evidence from in vitro studies of brown adipose tissue in Syrian hamsters indicates a significant degree of recruitment of the tissue as an effect of cold acclimation. However, earlier in vivo studies indicate a lack of recruitment of nonshivering thermogenesis in the intact animal as a result of cold acclimation. Because of this apparent discrepancy, the occurrence of cold acclimation-recruited nonshivering thermogenesis in hamsters was investigated. Hamsters were cold acclimated to 6 degrees C or remained at 24 degrees C (controls), and their thermogenic response was investigated in an open-circuit system at 24 degrees C. Cold acclimation resulted in a small increase in resting metabolic rate and a major increase in the thermogenic response to norepinephrine (61% increase over resting metabolic rate in controls and 156% increase in cold-acclimated animals). The absolute beta 3-specific adrenergic agonist CGP-12177 also induced a high rate of nonshivering thermogenesis, which was similarly recruited. It was concluded that, concerning the relative effect of recruitment on the capacity for nonshivering thermogenesis, the intact hamsters responded as would be predicted from in vitro experiments. Thus the hamster does not seem to constitute an exception to the general patterns described for other rodents concerning recruitment of nonshivering thermogenesis due to cold acclimation.

scholarly journals Dynamic modelling of cold-hardiness in tea buds by imitating past temperature memory

2020 ◽  
Author(s):  
Kensuke Kimura ◽  
Daisuke Yasutake ◽  
Takahiro Oki ◽  
Koichiro Yoshida ◽  
Masaharu Kitano
Keyword(s):  
Cold Stress ◽  
Cold Acclimation ◽  
Dynamic Model ◽  
Cold Hardiness ◽  
Global Climate ◽  
Effective Means ◽  
Dynamic Modelling ◽  
Short Term ◽  
Mean Square Errors

Abstract Background and Aims Most perennial plants memorize cold stress for a certain period and retrieve the memories for cold acclimation and deacclimation, which leads to seasonal changes in cold-hardiness. Therefore, a model for evaluating cold stress memories is required for predicting cold-hardiness and for future frost risk assessments under warming climates. In this study we develop a new dynamic model of cold-hardiness by introducing a function imitating past temperature memory in the processes of cold acclimation and deacclimation. Methods We formulated the past temperature memory for plants using thermal time weighted by a forgetting function, and thereby proposed a dynamic model of cold-hardiness. We used the buds of tea plants (Camellia sinensis) from two cultivars, ‘Yabukita’ and ‘Yutakamidori’, to calibrate and validate this model based on 10 years of observed cold-hardiness data. Key Results The model captured more than 90 % of the observed variation in cold-hardiness and predicted accurate values for both cultivars, with root mean square errors of ~1.0 °C. The optimized forgetting function indicated that the tea buds memorized both short-term (recent days) and long-term (previous months) temperatures. The memories can drive short-term processes such as increasing/decreasing the content of carbohydrates, proteins and antioxidants in the buds, as well as long-term processes such as determining the bud phenological stage, both of which vary with cold-hardiness. Conclusions The use of a forgetting function is an effective means of understanding temperature memories in plants and will aid in developing reliable predictions of cold-hardiness for various plant species under global climate warming.

Changes in carbohydrates, ABA and bark proteins during seasonal cold acclimation and deacclimation inHydrangeaspecies differing in cold hardiness

2008 ◽  
Vol 134 (3) ◽  
pp. 473-485 ◽  
Author(s):  
Majken Pagter ◽  
Christian R. Jensen ◽  
Karen K. Petersen ◽  
Fulai Liu ◽  
Rajeev Arora
Keyword(s):  
Cold Acclimation ◽  
Cold Hardiness

scholarly journals miR-31-5p regulates cold acclimation of the wood-boring beetle Monochamus alternatus via ascaroside signaling

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Bin Zhang ◽  
Lilin Zhao ◽  
Jing Ning ◽  
Jacob D. Wickham ◽  
Haokai Tian ◽  
...  
Keyword(s):  
Cold Stress ◽  
Cold Acclimation ◽  
Cold Adaptation ◽  
Cold Hardiness ◽  
Expression Patterns ◽  
Specific Gene ◽  
Metabolic Depression ◽  
Monochamus Alternatus ◽  
Freeze Avoidance ◽  
Thermal Plasticity

Abstract Background Survival to cold stress in insects living in temperate environments requires the deployment of strategies that lead to physiological changes involved in freeze tolerance or freeze avoidance. These strategies may consist of, for instance, the induction of metabolic depression, accumulation of cryoprotectants, or the production of antifreeze proteins, however, little is known about the way such mechanisms are regulated and the signals involved in their activation. Ascarosides are signaling molecules usually known to regulate nematode behavior and development, whose expression was recently found to relate to thermal plasticity in the Japanese pine sawyer beetle Monochamus alternatus. Accumulating evidence also points to miRNAs as another class of regulators differentially expressed in response to cold stress, which are predicted to target genes involved in cold adaptation of insects. Here, we demonstrate a novel pathway involved in insect cold acclimation, through miRNA-mediated regulation of ascaroside function. Results We initially discovered that experimental cold acclimation can enhance the beetle’s cold hardiness. Through screening and functional verification, we found miR-31-5p, upregulated under cold stress, significantly contributes to this enhancement. Mechanistically, miR-31-5p promotes production of an ascaroside (asc-C9) in the beetle by negatively targeting the rate-limiting enzyme, acyl-CoA oxidase in peroxisomal β-oxidation cycles. Feeding experiments with synthetic asc-C9 suggests it may serve as a signal to promote cold acclimation through metabolic depression and accumulation of cryoprotectants with specific gene expression patterns. Conclusions Our results point to important roles of miRNA-mediated regulation of ascaroside function in insect cold adaptation. This enhanced cold tolerance may allow higher survival of M. alternatus in winter and be pivotal in shaping its wide distribution range, greatly expanding the threat of pine wilt disease, and thus can also inspire the development of ascaroside-based pest management strategies.

USE OF CONTROLLED ENVIRONMENTS FOR WINTER CEREAL COLD HARDINESS EVALUATION: CONTROLLED FREEZE TESTS AND TISSUE WATER CONTENT AS PREDICTION TESTS

1989 ◽  
Vol 69 (2) ◽  
pp. 355-366 ◽  
Author(s):  
A. L. BRULE-BABEL ◽  
D. B. FOWLER
Keyword(s):  
Water Content ◽  
Cold Acclimation ◽  
Cold Hardiness ◽  
Screening Method ◽  
Strong Relationship ◽  
Winter Rye ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Winter Cereal ◽  
Controlled Environments

Field survival is the most commonly employed method of evaluating the winter hardiness of cereals. However, the inherent difficulties with field trials have stimulated a continued interest in the use of controlled environments and prediction tests for the evaluation of cold hardiness. In the present studies, cold hardiness expression of wheat (Triticum aestivum L.) cultivars acclimated in controlled environments was found to be similar to that reported for field conditions in Saskatchewan, Canada. LT50 and tissue water content measurements on wheat and rye (Secale cereale L.) cultivars acclimated in controlled environments were highly correlated with cultivar field survival ability. Investigation of the relationship between field survival and tissue water content during cold acclimation in controlled environments indicated that, to be effective as a screening method for cold hardiness, measurements of tissue water content should be made on fully acclimated plants for which the acclimation conditions have been rigorously controlled. Level of acclimation was not as critical for cold hardiness screening when LT50 measurements were utilized; however, maximum resolution also required fully acclimated plants. Although a strong relationship (r = −0.80 to −0.89) was found to exist with field survival potential, an inability to detect small, but important, differences without excessive replication would generally restrict the use of LT50 and tissue water content to situations where large homogeneous plant populations were available and only coarse screens for cold hardiness were required.Key words: Cold acclimation, winter wheat, winter rye, cold hardiness, water content, replication

Cold-hardiness of olive (Olea europaeaL.) cultivars in cold-acclimated and non-acclimated stages: seasonal alteration of antioxidative enzymes and dehydrin-like proteins

2008 ◽  
Vol 147 (1) ◽  
pp. 51-61 ◽  
Author(s):  
A. CANSEV ◽  
H. GULEN ◽  
A. ERIS
Keyword(s):  
Nadph Oxidase ◽  
Cold Acclimation ◽  
Antioxidative Enzymes ◽  
Nicotinamide Adenine Dinucleotide ◽  
Cold Hardiness ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Seasonal Patterns ◽  
Sds Page ◽  
Olive Cultivars ◽  
Old Trees

SUMMARYSeasonal patterns of antioxidative enzymes and proteins and their relations to cold-hardiness of nine olive (Olea europaeaL.) cultivars (Ascolona, Domat, Gemlik, Hojoblanca, Lecquest, Manzanilla, Meski, Samanli and Uslu) are documented in the current study. Fully expanded, uniformly sized leaves from 2-year-old shoots of the cultivars were collected from 20-year-old trees in cold-acclimated (CA, in January) and non-acclimated (NA, in July) stages. Leaf samples were exposed to low temperature at 4, −5, −10 and −20°C for 12 h to determine their cold-hardiness (LT50; assessed by electrolyte leakage). Cold-acclimation produced an increase in freezing tolerance of all cultivars (by lowering LT50). Domat and Lecquest were found to have the highest cold-hardiness among the nine cultivars investigated. Ascolona, Gemlik, Hojoblanca had moderate cold-hardiness, while Samanli, Meski, Uslu and Manzanilla were more sensitive. Activities of catalase (CAT: EC 1·11·1·6), ascorbate peroxidase (APX: EC 1·11·1·11) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase significantly varied depending on the cold-acclimation stage and the cold-hardiness level of the cultivars. Activities of the three antioxidative enzymes and total soluble proteins (TSP) were higher in the CA stage than in the NA stage. Although no accumulation of major polypeptides, except a 23 kDa protein, was detected either in CA samples or NA samples by SDS-PAGE, anti-dehydrin immunoblots revealed that the 43 and 23 kDa polypeptides were detectable during cold-acclimation of olive cultivars. Accumulation of both 43 and 23 kDa dehydrin was significantly higher in the CA stage than in the NA stage in all cultivars. Accumulation of 43 kDa dehydrin was correlated with cold-hardiness of the cultivars, while 23 kDa dehydrin was considered as cultivar-dependent since its accumulation was not parallel to LT50values of the cultivars. Indeed, the tissues of cvs Domat, Lecquest, Ascolona, Hojoblanca and Gemlik were found to enhance the structural stability of cellular membranes in the CA stage by increasing both the activity of such enzymes as CAT, APX and NADPH oxidase to activate the antioxidative systems and the expression of 43 kDa dehydrins.

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