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
2010 ◽  
Vol 28 (4) ◽  
pp. 235-239
Author(s):  
Frank P. Henning ◽  
Timothy J. Smalley ◽  
Orville M. Lindstrom ◽  
John M. Ruter

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.


2020 ◽  
Author(s):  
Kensuke Kimura ◽  
Daisuke Yasutake ◽  
Takahiro Oki ◽  
Koichiro Yoshida ◽  
Masaharu Kitano

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.


BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Bin Zhang ◽  
Lilin Zhao ◽  
Jing Ning ◽  
Jacob D. Wickham ◽  
Haokai Tian ◽  
...  

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.


1989 ◽  
Vol 69 (2) ◽  
pp. 355-366 ◽  
Author(s):  
A. L. BRULE-BABEL ◽  
D. B. FOWLER

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


2008 ◽  
Vol 147 (1) ◽  
pp. 51-61 ◽  
Author(s):  
A. CANSEV ◽  
H. GULEN ◽  
A. ERIS

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.


Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 379
Author(s):  
Lin Ouyang ◽  
Leen Leus ◽  
Ellen De Keyser ◽  
Marie-Christine Van Labeke

Rose is the most economically important ornamental plant. However, cold stress seriously affects the survival and regrowth of garden roses in northern regions. Cold acclimation was studied using two genotypes (Rosa wichurana and R. hybrida ‘Yesterday’) selected from a rose breeding program. During the winter season (November to April), the cold hardiness of stems, soluble sugar content, and expression of dehydrins and the related key genes in the soluble sugar metabolism were analyzed. ‘Yesterday’ is more cold-hardy and acclimated faster, reaching its maximum cold hardiness in December. R. wichurana is relatively less cold-hardy, only reaching its maximum cold hardiness in January after prolonged exposure to freezing temperatures. Dehydrin transcripts accumulated significantly during November–January in both genotypes. Soluble sugars are highly involved in cold acclimation, with sucrose and oligosaccharides significantly correlated with cold hardiness. Sucrose occupied the highest proportion of total soluble sugars in both genotypes. During November–January, downregulation of RhSUS was found in both genotypes, while upregulation of RhSPS was observed in ‘Yesterday’ and upregulation of RhINV2 was found in R. wichurana. Oligosaccharides accumulated from November to February and decreased to a significantly low level in April. RhRS6 had a significant upregulation in December in R. wichurana. This study provides insight into the cold acclimation mechanism of roses by combining transcription patterns with metabolite quantification.


2004 ◽  
Vol 129 (3) ◽  
pp. 354-359 ◽  
Author(s):  
Calin O. Marian ◽  
Atilla Eris ◽  
Stephen L. Krebs ◽  
Rajeev Arora

The influence of photoperiod and temperature on the seasonal (fall to winter) cold acclimation and accumulation of a 25 kDa dehydrin in Rhododendron `Chionoides' was studied by exposing two groups of plants each in the greenhouse or outdoors to either a natural photoperiod (or short days) or an extended photoperiod (or long days) regime. Results suggest that the shortening daylength alone is sufficient to trigger both the first stage of cold acclimation and concomitant 25 kDa dehydrin induction. Exposure of the plants to natural photoperiod and temperatures induced the greatest cold hardiness and 25 kDa accumulation, while exposure to extended photoperiods (long days) and warmer temperatures (in the greenhouse) failed to induce any significant freezing tolerance in leaves. Whereas short days trigger the cold acclimation process initially, low inductive temperatures can eventually replace the photoperiod stimulus. Seasonal accumulation of 25 kDa dehydrin, on the other hand, appears to be predominantly effected by short photoperiods. Data indicated that the leaf water content of outdoor plants maintained under natural photoperiod was lower than that of plants grown under extended photoperiod. This was also true for the greenhouse plants at the first (September) and the last (January) sampling. It is hypothesized that early 25 kDa dehydrin accumulation may be due to short-day-induced cellular dehydration. Accumulation of two other dehydrins of 26 kDa and 32 kDa molecular masses does not appear to be associated with short day (SD)-induced first stage of cold acclimation. Results show that their accumulation may be regulated by low, subfreezing temperatures and may be associated with the second and/or third stage of cold acclimation of `Chionoides' rhododendron leaves.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 858A-858
Author(s):  
Sameera Bafeel* ◽  
Frank Matta

Temperature is a major environmental factor governing the distribution of both wild and cultivated plant species. During acclimation and deacclimation plants undergo a series of metabolic changes that lead to cold hardiness or loss of hardiness. One of these changes is the accumulation of certain lipids. This research was conducted to compare hardiness among three pecan cultivars: `Desirable', `Jackson', and `Owens' growing under Mississippi condition and to determine the relationship between fatty acid levels and cold hardiness of pecan shoots. Differential thermal analysis (DTA), electrical conductivity, and tetrazolium tests were used to determine cold hardiness. Pecan stems were collected from September to March in 2002 and 2003 to determine cold acclimation and deacclimation. Fatty acid composition of pecan stems during this time period was determined by gas chromatography. DTA indicated that pecan stems acclimated in October and deacclimated in March. During cold acclimation, there was a shift in the fatty acid composition to more unsaturated fatty acids. The percentage of linoleic and linolenic fatty acids increased, while the percentage of palmitic and stearic fatty acids decreased. The correlation between unsaturated fatty acids and cold hardiness suggests that unsaturated fatty acid may play a role in membrane fluidity.


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