• Journal of Photoscience
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• v.12 no.1
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.450-460
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• 2020

The occurrence of exotic weeds and their influx into farmlands due to climate change poses many problems. Therefore, it is necessary to generate a prediction model for the occurrence pattern of these exotic weeds based on scientific evidence and devise prevention measures. The photosynthetic apparatus is known as the most temperature-sensitive component of a plant cell and its initial response to temperature stress is to inhibit the activation of photosystem II. This study investigated the potential of OJIP transients in assessing temperature stress in exotic weeds. The four exotic weeds currently flowing into Korean farmlands include Amaranthus spinosus, Conyza bonariensis, Crassocephalum crepidioides, and Amaranthus viridis. These weeds were treated at 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, and 40℃ and the OJIP curves and JIP parameters were measured and analyzed. The results showed that heat and chilling stress affected the photosystem II(PSII) electron transport of A. spinosus, whereas C. crepidioides and A. viridis were more affected by high-temperature stress than by low-temperature stress. Lastly, C. bonariensis showed resistance to both high and low-temperature stress. The results of this study suggest that OJIP transients and JIP parameters can be used to analyze damage to the photosynthetic apparatus by temperature stress and that they can serve as sensitive indicators for the occurrence pattern of exotic weeds.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.141-145
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• 2013

The aim of this study was to investigate the effect of two male cultivars of asparagus with low different chilling periods on bud breaking, relative spear growth rate, shoot number and yield. Four-month-old plants of two male cultivars of asparagus were dried to impose dormancy and placed in a coldroom at $5^{\circ}C$ to satisfy the chilling requirement for 0, 2, 4, and 6 weeks. After the specified chilling time, the pots were placed in greenhouse. The results showed that mean days to bud break of 'Jersey Giant' significantly decreased with an increasing chilling period from 0 to 6 weeks, but 'Jersey Supreme' was not affected. The relative spear growth rate of 'Jersey Supreme' was significantly stimulated by chilling compared to non-chilled plants. Shoot production and total spear weight of 'Jersey Supreme' tended to be greater than 'Jersey Giant' irrespective of chilling treatments. Following low temperature treatment, 'Jersey Supreme' showed shorter dormant period than 'Jersey Giant', faster growth of spear. The present study showed that asparagus male cultivar at duration of chilling treatment had an affirmative effect on bud breaking, spear growth rates, shoot number and yield of asparagus.

• Food Science and Preservation
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• v.18 no.5
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• pp.651-660
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• 2011

This study was conducted to evaluate the quality characteristics of and chilling injury development in 'Ooishiwase' plum fruits after harvest, according to the ripening stage and storage temperature. The fruits were harvested at three ripening stages (60, 80, and >90% skin color) and were then stored at 1, 4, 5, 6, and $20^{\circ}C$ cold-storage rooms for up to 48 days. The fruit quality parameters, respiration patterns, and chilling injury development were monitored during the storage periods and the three days of subsequent ripening at $20^{\circ}C$. The fruits harvested at the 60%-skin-color stage maintained the flesh firmness, color, weight loss, and TA, and their respiration rates and ethylene production were decreased compared with the 80%-or >90%-skin-color fruits, at a lower storage temperature. The major symptoms of chilling injuries in the Ooishiwase plums were gel breakdown, flesh browning, and flesh translucency. These symptoms appeared at all the low-storage-temperature and ripening treatment stages. When the fruits, however, were harvested at a more immature stage and were stored at a lower storage temperature, the chilling injury development decreased. These results show that the development of chilling injury in Ooishiwase plums is related to the climacteric behavior during cold storage.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.75-83
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• 2014

Recently, a quick drop of air temperature in plastic film houses by adverse weather conditions leads to the occurrence of low temperature damages to growing crops. Chilling injury, defined as a variety of growth restriction occurring below the optimal temperature, is one of environmental factors strongly affecting crop growth and yield. Low temperature causes the restricted evapotranspiration, reduced mineral uptake (P > K > $NO_3{^-}$), and an increase in electrolyte leakage such as K. Despite being different with plant species, an accumulation of soluble carbohydrates such as glucose, fructose, sucrose and starch under chilling condition is well known. A variety of environmental stresses are known to cause oxidative damage to plants either directly or indirectly by triggering an increased level of production of reactive oxygen species (ROS), and, to combat the oxidative damage, plants have the antioxidant defense systems comprising of enzymes, SOD, POD, CAT, GPX and APX, and non-enzymes, ascorbate, gluthathione, ${\alpha}$-tocopherol, phenolic compounds, carotenoid and flavonoids. The aim of this review is to provide basic information to build chilling-indicators and optimal nutrition management under adverse temperature conditions as broadly considering mineral uptake, carbohydrate metabolism and antioxidative defense system.

• Korean Journal of Plant Resources
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• v.23 no.1
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• pp.25-30
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• 2010

This study was carried out to understand the effect of low temperature($4^{\circ}C$), heat shock($37^{\circ}C$) and drought stresses on the growth and gene expression of Arabidopsis ATSIZ3(at1g08910) mutants. The seedling growth of SIZ3-mutants were markedly inhibited by the treatment of heat shock or chilling stresses. However, there was no significant differences between wild type and SIZ3-mutants in seeding fresh weight. As compared to wild type plants, SIZ3-mutants showed 63.9% inhibition of seedling fresh weight by the treatment of 10 days drought stress, suggesting that SIZ3 is involved in the resistance of Arabidopsis to drought stress. Base on RT-PCR analysis, expression of SIZ3 mRNA in the wild type showed 20% inhibition by chilling stress, 3.7 and 4.5 fold increase by the treatment of heat shock or drought stresses, respectively.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.168-168
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• 2002

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.181-181
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• 2002

• Journal of Food Hygiene and Safety
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• v.3 no.1
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• pp.27-36
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• 1988

Generally, carrier chickens contaminate the processing plant equipment to such an extent that negative chickens procell afterwards result in contaminated. meat. This study was performed to investigate the prevalence of Complliobacter jejuni in two chicken procelling plants. Altogether two hundred samples were collected from cloaca, carcasses, chilling water, and evis-cerationknives at different processing stages during the period of June to September 1987. The isolated organisms were tested for distribution of biotype, serotype. The results obtained were summarized as follows: 1. C. jejuni was isolated from 41(34.2%) of 120 chicken feces, 9(45.0%) of 20 carC888eS before chilling, 11(55.0%) of 20 carcasses after chilling, 12(60.0%) of 20 eviscerationlmives. The evilceration knives and chilling water were considered as major means of croll contamination. 2. In biotyping 82 isolates of C. jejuni, 64(78.1%) were cl888ified as biotype I, and 18(21.9%) belonged to biotype II. 3. In serotyping 82 isolates of C. jejuni, 64(78.1%) were identified as serotype LIO 37, and 18(21.9%) were untypable.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.347-351
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• 2003

This experiment was carried out to study the optimal chilling period for breaking the physiological dormancy of dehisced E. senticosus seeds and to investigate the critical seeding date in Kangwondo. Storage at $5^{\circ}C$ for 85 days was most effective in breaking dormancy of dehisced seeds, but didn't germinated synchronously. Only 28.1% of undehisced seeds germinated after 125 days of low temperature storage. For improving seedling survival rate in the field, 50% shading was more effective than 30% shading. Delayed seeding date resulted in decreased seedling fresh weight, dry weight, leaf area and root length, but seeding date has no significant affecte on stem length.