• Molecules and Cells
• /
• v.39 no.3
• /
• pp.250-257
• /
• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Journal of Ecology and Environment
• /
• v.29 no.5
• /
• pp.479-484
• /
• 2006

Ecophysiological parameters of non-transgenic sweetpotato (NT) and transgenic sweetpotato (SSA) plants were compared to evaluate their resistance to multiple environmental stresses. Stomatal conductance and transpiration rate in NT plants decreased markedly from Day 6 after water was withheld, whereas those values in SSA plants showed relatively higher level during this period. Osmotic potential in SSA plants was reduced more negatively as leaf water potential decreased from Day 8 after dehydration treatment, while such reduction was not shown in NT plants under water stressed condition. SSA plants showed less membrane damage than in NT plants. As water stress and high light stress, were synchronously applied to NT and SSA plants maximal photochemical efficiency of PS II ($F_v/F_m$) in NT plants markedly decreased, while that in SSA plants was maintained relatively higher level. This trend of changes in $F_v/F_m$ between SSA plants and NT plants was more conspicuous as simultaneously treated with water stress, high light and high temperature stress. These results indicate that SSA plants are more resistive than NT plants to multiple environmental stresses and the enhanced resistive characteristics in SSA plants are based on osmotic adjustment under water stress condition and tolerance of membrane.

• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.429-435
• /
• 2011

The demand of packaged baby leaves has been increased for its convenient use as fresh-cut produce. This investigation was aimed to explore the effects of different sanitizers on the quality parameters of 'Tah Tasai' Chinese cabbage (Brassica campestris var. narinosa) baby leaves. Thirteen days old baby leaves were harvested and washed in tap water (TW), 100 ppm chlorine solution (Cl), 2 ppm ozonated water ($O_3$), 15 ppm chlorine dioxide solution ($ClO_2$) and washing with 0.2% citric acid solution followed by 50% ethanol spray (CA+Et). The samples were then packaged in 50 ${\mu}m$ polyethylene bags and stored at $5^{\circ}C$ for 10 days. Off-odor of packaged baby leaves was not detected during storage. There was no significant difference in color parameters among the treatments. Samples treated with $O_3$ showed substantially higher electrolyte leakage throughout the storage. This treatment also rendered a higher accumulation of $CO_2$ in the packages. Samples treated with Cl and CA+Et maintained good overall visual quality with higher scores compared to that of $O_3$ and $ClO_2$. Although Cl treatment showed lower number of total aerobic count at the beginning of storage, citric acid in combination with ethanol treatment was more effective until the end of storage. The combined treatment also showed comparatively lower coliform plate count. This result indicates that citric acid wash followed by ethanol spray could be an alternative to chlorine for environment friendly sanitization of baby leaves.

• Korean Journal of Soil Science and Fertilizer
• /
• v.51 no.2
• /
• pp.119-127
• /
• 2018

Veterinary antibiotics (VAs) has been used to treat animal disease and to increase body weight. However, released VAs in the soil via spreading of compost can transport to plant and affect its growth. Main purpose of this research was i) to monitor VAs concentration in plant and ii) to evaluate inhibition effect of VAs residuals on the plant growth. Red lettuce (Lactuca sativa) was cultivated for 35 days in the pot soil spiked with 3 different concertation (0.05, 0.5, $5.0mg\;kg^{-1}$) of chlortetracycline (CTC) and sulfamethazine (SMZ). After 35 days of cultivation, concentration of CTC and SMZ in the plant was measured. Residual of CTC and SMZ was only quantified at the range of $0.007-0.008mg\;kg^{-1}$ and $0.006-0.017mg\;kg^{-1}$ in the leaf and root respectively when high concentration ($5.0mg\;kg^{-1}$) of antibiotic was spiked in the soil. Leaf length and root mass was statistically reduced when $0.05mg\;kg^{-1}$ of CTC was spiked in the soil while no statistical difference was observed for SMZ treatment. This result might indicated that high $K_{ow}$ and $K_d$ value are the main parameters for inhibiting plant growth. Antibiotics that has a high $K_{ow}$ causing hydrophobicity and easy to bioaccumulate in the lipid cell membrane. Also, antibiotics that has a high $K_d$ properties can be sorbed in the root causing growth inhibition of the plant. Overall, management of VAs should be conducted to minimize adverse effect of VAs in the ecosystem.

• Transactions of the Korean hydrogen and new energy society
• /
• v.23 no.5
• /
• pp.468-475
• /
• 2012

A proper stacking force and assembly are important to the performance of fuel cell. Improper assembly pressure may lead to leakage of fuels and high interfacial contact resistance, excessive assembly pressure may result in damage to the gas diffusion layer and other components. The pressure distribution of gas diffusion layer is important to make interfacial contact resistance less for stack performance. To analyze the influence of design parameter factors for pressure distribution, and to optimize stack design, DOE (Design of Experiment) was used for polymer electrolyte membrane fuel cell stack pressure test. As commonly known, the higher clamping force improves the fuel cell stack performance. However, non-uniformity of stress distribution is also increased. It shows that optimization between clamping force and stress distribution is needed for well designed structure of fuel cell stack. In this study, stack design optimization method is suggested by using FEM (Finite Element Methode) and DOE for light-weighted fuel cell stack.

• Advances in environmental research
• /
• v.3 no.4
• /
• pp.307-319
• /
• 2014

Four chickpea cultivars viz. kabuli (Pusa 1088 and Pusa 1053) and desi (Pusa 1103 and Pusa 547) differing in sensitivity to high temperature conditions were analyzed in earthern pot (30 cm) at different stages of growth and development in the year of 2010 and 2011. Pusa-1053 (kabuli type) showed maximum photosynthetic rate and least by Pusa-547 (desi type), whereas maximum cell membrane thermostability were recorded in Pusa-1103 and minimum in Pusa-1088. Among the treatments, the plants grown under elevated temperature conditions had produced 13.01% more significant data in comparison to plants grown under continuous natural conditions. Stomatal conductance were reduced 44.25% under elevated temperature conditions than natural conditions, whereas 35.56%, when plants grown under initially natural conditions upto 30DAS, then 30-60DAS elevated temperature and finally shifted to natural conditions till harvest. In case of Pusa-1103, stomatal conductance was maximum as compared to rest of 2.7% from Pusa-1053, 8.9% from Pusa-1088, and 10.3% in Pusa-547 throughout the study. Plants grown under continuous elevated temperature conditions had produced 15.30% and 15.32% more significant membrane thermostability index in comparison to continuous natural conditions at vegetative stage and 19.40% and 18.44% at flowering stage, while the better response was recorded at pod formation stage. Pusa-1053 had given 2.8% more membrane thermostability index than Pusa-1088 and Pusa-1103 had given 1.6% more membrane thermostability index than Pusa-547 in the present study. The membrane disruption caused by high temperature may alter water ion and inorganic solutes movement, photosynthesis and respiration. Thus, thermostability of the cell membrane depends on the degree of the electrolyte leakage.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.7
• /
• pp.1124-1136
• /
• 2019

Salinity is one of the major abiotic stresses that cause reduction of plant growth and crop productivity. It has been reported that plant growth-promoting bacteria (PGPB) could confer abiotic stress tolerance to plants. In a previous study, we screened bacterial strains capable of enhancing plant health under abiotic stresses and identified these strains based on 16s rRNA sequencing analysis. In this study, we investigated the effects of two selected strains, Bacillus aryabhattai H19-1 and B. mesonae H20-5, on responses of tomato plants against salinity stress. As a result, they alleviated decrease in plant growth and chlorophyll content; only strain H19-1 increased carotenoid content compared to that in untreated plants under salinity stress. Strains H19-1 and H20-5 significantly decreased electrolyte leakage, whereas they increased $Ca^{2+}$ content compared to that in the untreated control. Our results also indicated that H20-5-treated plants accumulated significantly higher levels of proline, abscisic acid (ABA), and antioxidant enzyme activities compared to untreated and H19-1-treated plants during salinity stress. Moreover, strain H20-5 upregulated 9-cisepoxycarotenoid dioxygenase 1 (NCED1) and abscisic acid-response element-binding proteins 1 (AREB1) genes, otherwise strain H19-1 downregulated AREB1 in tomato plants after the salinity challenge. These findings demonstrated that strains H19-1 and H20-5 induced ABA-independent and -dependent salinity tolerance, respectively, in tomato plants, therefore these strains can be used as effective bio-fertilizers for sustainable agriculture.

• Food Science and Industry
• /
• v.50 no.2
• /
• pp.12-26
• /
• 2017

Processing steps such as washing and cutting, involved in preparing fresh-cut produce causes tissue damage, leading to rapid quality deterioration. Major defects of fresh-cut produce are discoloration, softening, off-odor development, and microbial growth. Packaging of fresh-cut produce has been changed to reduce these quality problems. Flexible packaging film is widely used to pack fresh-cut produce. Vacuum packaging was the popular packaging method in the beginning of fresh-cut industry in Korea. Vacuum packaging creates high $CO_2$ and low $O_2$ levels to control browning of fresh-cut produce. However, these conditions induce some visual defects and off-odor development. Discoloration problem was also found when fresh-cut produce was packaged with conventional packaging film or plastic tray. Modified atmosphere (MA) packaging is effective for prolonging shelf-life of fresh-cut produce by decreasing $O_2$ and increasing $CO_2$ concentration in the package. Retail MA packaging using different oxygen transmission rate (OTR) film and micro-perforated film has started to be applied to fresh-cut produce in Korea. Proper MA package design that provides optimum range of $O_2$ and $CO_2$ partial pressures is one of the major challenges in the industry. An initial package flushing with $N_2$ or an low $O_2$/high $CO_2$ atmosphere is also used to more rapidly establish steady-state MA condition. Film OTR and $O_2$ flushing affects the fermentative volatile production, off-odor development, electrolyte leakage, discoloration, $CO_2$ injury, microbial population of fresh-cut produce. There is also a demand for convenient packaging to attract consumers. Rigid fresh-cut produce container for retail market has increased since the packaging provides excellent protection from physical damage during transport. Rigid tray used as actual serving vessel for the consumer is increasing in Korea. The tray with flexible lid to wrap or seal fresh-cut produce is more and more gaining popularity. Further practical technology to control quality change and microbial growth for each fresh-cut product has been studied since various fresh-cut items were required. The fresh-cut industry also focuses on searching for more convenient and environmentally friendly packaging.

• Journal of Plant Biotechnology
• /
• v.50
• /
• pp.115-126
• /
• 2023

A hydroponics experiment was performed to study the physiological and biochemical changes in Moroccan barley (Hordeum vulgare L.) varieties cultivated under salt stress conditions. Four barley varieties were grown under exposure to three salt concentrations, including 0, 200, and 300 mM NaCl. The ANOVA for both salt stress-sensitive and resistant varieties indicated that salt treatment represented the main source of variability in all studied traits. Salt treatment significantly reduced root and shoot dry weight (RDW and SDW), relative water content (RWC), and chlorophyll content (Chl a, Chl b, and Chl T). However, increases in electrolyte leakage (EL) along with proline and total soluble sugar (TSS) contents were recorded. In addition, large variations in all measured traits were found between varieties. The 'Massine' and 'Laanaceur' varieties displayed relatively higher RDW and SDW values. The 'Amira' and 'Adrar' varieties showed lower RWC values and Chl contents than those of the controls indicating their relative sensitivity to salt stress. Principal component analysis revealed that most of the variation was captured by PC1 (72% of the total variance) which grouped samples into three categories according to salt treatment. Correlation analyses highlighted significant associations between most parameters. Positive relationships were found between RDW, SDW, RWC, Chl content, and soluble proteins contents, while all of these parameters were negatively associated with EL intensity, proline content, and TSS content. The results from this study showed that the 'Massine' and 'Laanaceur' varieties were relatively salt-tolerant. These two salt-tolerant varieties present a good genetic background for breeding of barley varieties showing high salt tolerance.

• The Korean Journal of Pesticide Science
• /
• v.2 no.3
• /
• pp.107-116
• /
• 1998

Based on the differential growth response to exogenous gibberellic acid ($GA_{3}$) between semi-dwarf wheat(Triticum aestivum) and wild oat(Avena fatua), we examined the possibility of improving the selective performance of several herbicides by $GA_{3}$ application and the physiological background of $GA_{3}$-induced increase in herbicidal activity. Growth of wild oat was 4 to 5 times higher than that of wheat by $GA_{3}$ treatment. Pretreatment of wild oat seed with 300 ppm $GA_{3}$ increased the herbicidal activities of trifluralin and isoproturon by soil-surface application, but not of alachor and metsulfuron-methyl. $GA_{3}$ applied simultaneously with post-emergence herbicides resulted in a significant or moderate improvement of the efficacy of such herbicides as tralkoxydim, fenoxaprop-ethyl, metsulfuron-methyl, metribuzine and isoproturon, but not in the mixtures of oxyfluorfen or paraquat with $GA_{3}$. In the sequencial treatment of tralkoxydim and $GA_{3}$ at interval of one-day, $GA_{3}$ applied prior to tralkoxydim significantly increased a chlorosis and desiccation of leaf without affecting the growth inhibition by tralkoxydim. Tralkoxydim followed by $GA_{3}$ application had lower herbicidal activity than that of $GA_{3}$ followed by tralkoxydim treatment. Electrolyte leakage response of $GA_{3}$-pretreated or $GA_{3}$-untreated wild oat leaf against several compounds inducing membrane. peroxidation was compared. Differencial responses were observed in oxyfluorfen and isoproturon treatments with an increased electrolyte leakage in $GA_{3}$-pretreated tissue, but not in paraquat and rose bengal treatments. These results suggest that $GA_{3}$-induced increase in herbicidal activity is likely to be dependent on a herbicide type and may be due to activation of a metabolic ability related with herbicidal reponse as well as an increase in the herbicide absorbtion and translocation, rather than due to membrane and cell wall extention induced by $GA_{3}$, which in turn makes the herbicides easily enter.