Geminiviruses are plant-infecting viruses with monopartite or bipartite single-stranded circular DNA genomes. They are known to be mediated by insects such as whiteflies, treehoppers, leafhoppers or aphids and can cause devastating plant diseases in a wide range of economically significant crops worldwide. In Korea, occurrence of geminiviruses were reported officially after the 2000s. Although Honeysuckle yellow vein virus (HYVV) and Sweet potato leaf curl virus (SPLCV) were identified from honeysuckle and sweet potato in 2004 and 2006 respectively, these viruses did not spread and cause much concern for geminiviruses. In 2008, Tomato yellow leaf curl virus (TYLCV) that has caused severe tomato production loss in many subtropical and tropical countries was first reported in tomato plants cultivated in Tongyeong. TYLCV rapidly spread through the country and has been continuously reported from tomato cultivating areas in Korea. In addition to TYLCV, Tobacco leaf curl virus and Sweet potato golden vein associated virus have occurred. In recent years, new geminiviruses including Papaya leaf curl Guangdong virus (PaLCGdV) and Euphorbia leaf curl virus (EuLCV) have been introduced. Newly emerging geminiviruses from tropical and subtropical countries are due to increased demand for various fruits and vegetables, and climate change. In addition, there are reports that some geminiviruses including TYLCV can be transmitted by infected seeds. Therefore it is important to study on epidemiology of virus introduction and spread among the countries and within country.

Cold, salt and heat are the most critical factors that restrict full genetic potential, growth and development of crops globally. However, clarification of genes expression and regulation is a fundamental approach to understanding the adaptive response of plants under unfavorable environments. In this study, we applied an annealing control primer (ACP) based on the GeneFishing approach to identify differentially expressed genes (DEGs) in Italian ryegrass (cv. Kowinearly) leaves under cold, salt and heat stresses. Two-week-old seedlings were exposed to cold (4°C), salt (NaCl 200 mM) and heat (42°C) treatments for six hours. A total 8 differentially expressed genes were isolated from ryegrass leaves. These genes were sequenced then identified and validated using the National Center for Biotechnology Information (NCBI) database. We identified several promising genes encoding light harvesting chlorophyll a/b binding protein, alpha-glactosidase b, chromosome 3B, elongation factor 1-alpha, FLbaf106f03, Lolium multiflorum plastid, complete genome, translation initiation factor SUI1, and glyceraldehyde-3-phosphate dehydrogenase. These genes were potentially involved in photosynthesis, plant development, protein synthesis and abiotic stress tolerance in plants. However, this study provides new insight regarding molecular information about several genes in response to multiple abiotic stresses. Additionally, these genes may be useful for enhancement of abiotic stress tolerance in fodder crops as well a crop improvement under unfavorable environmental conditions.

Glutathione S-transferase (GST) is a key gene involved in multiple stress tolerance in all living organisms, though it is still to be disclosed the gene function in teff grass [Eragrostis tef (Zucc.)Trotter].The objectives of this study were to clone and molecular characterization of GST gene in teff grass. We characterized GST1 from teff grass (EtGST1), it composed of a 645-bp open reading frame (ORF) that encoded 195 amino acid residue. Further, we transformed EtGST1 in E.coli BL21 (DE3) cells. This recombinant EtGST1 in E.coli BL21(DE3) induced at 37°C temperature. In addition, Growth of cells overexpressing EtGST1 rapidly increased in the presence of polyethylene glycol (5%), heat (46°C), NaCl (0.6%), and arsenic (1 mM) than that of cells harboring an empty vector. These results suggest that EtGST1 would be suitable candidate for improving tolerance in forages and/or grasses species against multiple abiotic stresses.

Cold, salt and heat are most critical factors that restrict full genetic potential, growth and development of crops worldwide.. In this study, we applied an annealing control primer (ACP) based GeneFishing approach to identify differentially expressed genes (DEGs) in annual ryegrass (cv. Kowinearly) leaves under cold, salt and heat stresses. Two-week-old seedlings were exposed to cold (4°C), salt (NaCl 200 mM) and heat (42 °C) treatments for 6 h. A total 8 differentially expressed genes were isolated form ryegrass leaves. These genes were sequenced then identified and validated form National Center for Biotechnology Information (NCBI) database. We identified several promising genes encoding light harvesting chlorophyll a/b binding protein, alpha-glactosidase b, chromosome 3B, elongation factor 1-alpha, FLbaf106f03, complete genome, translation initiation factor SUI1, and glyceraldehyde-3-phosphate dehydrogenase. These genes were potentially involved in photosynthesis, plant development, protein synthesis and abiotic stress tolerance in plants. These genes might be useful for the enhancement of abiotic stress tolerance in fodder crops along with crop improvement under unfavorable environmental conditions.

Methyl benzoate (MB) is a natural compound in many plants and shows insecticidal toxicity against various insect pests. We determined contact, fumigant, and repellent activities of MB against the sweetpotato whitefly Bemisia tabaci and the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). Complete contact mortality was obtained by 4% MB. Contact mortality at 2% MB into eggs, 4th instar nymphs and adults were 69.4%, 91.6% and 80%, respectively. Fumigation of 2% MB killed 95% of adults. In addition, treatment of 4% MB repelled 60% adults. There was no significant different between two species. Our results suggest that MB has high potential as an natural pesticide for sustainable pest management in crop production.

Fungus gnat, Bradysia impatiens is the most serious pest of different vegetable crops, mushroom and ornamental crops. In this study, we compared the control efficacy of two entomopathogenic nematode; Steinernema carpocapsae and Heterorhabdistis indica in Bradysia impatiens last instar maggots at 25℃ in laboratory. Our present study shows that, nematode infection and reproduction both were higher in the warm adapted nematode H. indica than the cold adapted S. carpocapsae. Therefore, entomopathogenic nematode H. indica can be use for control the Badysia impatiens as the efficient biological control agent.

Heterodera trifolii, mostly known as clover cyst nematode, is currently a serious problem for Chinese cabbage growers of the highland area in Korea. Due to lack of readily information about the nematode on Chinese cabbage in Korea, the pest steadily spread within the highland areas and has become a serious setback. Occurrence, spatial aggregation, egg hatching and the pathogenicity of this nematode are depicted in this study from ecological point of view. The study results suggest site-specific control and a potential planting time for the cabbage to avoid severe damage caused by this nematode.

Drought is one of the detrimental factors that impair plant growth and productivity. In this study, we applied annealing control primer (ACP)-based reverse transcriptase PCR (polymerase chain reaction) technique to identify differentially expressed genes (DEGs) in maize leaves in response to drought stress. Two-week-old maize seedlings were exposed to drought (DT) by suspending water supply. DEGs were screened after 3 days of DT-treated samples using the ACP-based technique. Several DEGs encoding 16.9 protein, antimicrobial protein, hypothetical protein NCLIV_068840, thioredoxin M-type were identified in maize leaves under drought stress. These genes have putative functions in plant defense response, growth and development. These identified genes would be useful for predictive markers of plant defense, and growth responses under drought stress in plants.

Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) is an upstream signaling molecule that has been shown to induce stress tolerance in plants. In this study, the AtNDPK2 gene, under the control of a stress-inducible SWPA2 promoter, was introduced into the genome of tall fescue (Festuca arundinacea Schreb.) plants. The induction of the transgene expression mediated by methyl viologen (MV) and NaCl treatments were confirmed by RT-PCR and northern blot analysis, respectively. Under salt stress treatment, the transgenic tall fescue plants (SN) exhibited lower level of H2O2 and lipid peroxidation accumulations than the non-transgenic (NT) plants. The transgenic tall fescue plants also showed higher level of NDPK enzyme activity compared to NT plants. The SN plants were survived at 300 mM NaCl treatment, whereas the NT plants were severely affected. These results indicate that stress-inducible overexpression of AtNDPK2 might efficiently confer the salt stress tolerance in tall fescue plants.