• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.115-120
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• 2008

L-Ascorbic acid (vitamin C) in vegetables is an essential component of human nutrition. The objective is to transform lettuce (Lactuca sativa L.) with GalUR gene that is involved in the vitamin C biosynthesis. The cotyledons of Hwoahong (Nongwoo Bio Co.) were used to induce the callus and shoot under the selection media with MS + 30 g/L Sucrose + 0.5 mg/L BAP + 0.1 mg/L NAA + 100 mg/L kanamycin + 200 mg/L lilacillin, pH 5.2. The shoot was developed from the cut side of the explants after 3 weeks on the selection media. We successfully transformed the lettuce with GaIUR gene and analyzed the levels of vitamin C. We found that some of the lettuce transgenic lines contained higher levels of vitamin C compared with the normal one (non-transformed). Especially, some of $T_1$ lettuces inserted by GalUR showed about $3{\sim}4$ times higher content of vitamin C compared to the non-transformed lettuce. This data support the previously work performed with GLOase transgenic $T_1$ lettuces from which several times higher content of vitamin C were identified. The $T_2$ lettuces with high content of vitamin C have been selected for further analysis.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.697-705
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• 2023

Along with other heavy metals, arsenic (As) is one among the substances most harmful to living organisms including humans. Owing to its morphological similarity to phosphorus, the uptake of As is influenced by photosynthesis and the phosphorus uptake pathway. In this study, we varied arsenic exposure and light intensity during nutrient solution cultivation of lettuce (Lactuca sativa L.) to determine the effect of these two factors on arsenic uptake, lettuce growth, and electron transfer in photosystem II. In the treatment exposed to 30 μmol L^-1 of arsenic, the shoot arsenic concentration increased from 4.73 mg kg^-1 to 18.97 mg kg^-1 as the light intensity increased from 22 to 122 μmol m^-2 s^-1. The water content and ET2o/RC of the shoots were not affected by arsenic at low light intensity; however, at optimal light intensity, they decreased progressively with arsenic exposure. Increased light intensity stimulated the growth of plant roots and shoots; contrarily, the difference in growth decreased as the concentration of As exposure increased. The results of this study suggest that the effect of As on plant growth is dependent on light intensity; in particular, an increase in light intensity can increase the uptake of As, thereby affecting plant growth and As toxicity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.62-62
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• 2023

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.242-248
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• 1983

The effects of light source, plant growth regulators (GA, BA, ABA), and sodium hypochlorite (4% Cl, SH) on germination of 'G rand Rapid' lettuce (Lactuca sativa L.) seed were studied. Seed did not germinate under the conditions of dark and blue light. The treatment of GA or BA did not promote on germination under dark or blue light. The germination percentage under red light was very high, it was similar to the condition of white light. ABA inhibited lettuce seed germination. Although ABA was treated, BA 10ppm treatment was moderately effective under white light condition and BA 10ppm or 50ppm combined with GA 50ppm were also effective on seed germination under dark condition. Presoaking in sodium hypochlorite solution induced germination of lettuce seed in any condition of dark or white light. The optimum presoaking time in sodium hypochlorite solution was twenty min.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.376-381
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• 2009

The compositional analysis and the peroxynitrite ($ONOO^-$) scavenging assay were undertaken to demonstrate beneficial dietary effect of lettuce (Lactuca sativa L., Compositae). Quinic acid derivatives of the seven cultivars were qualitatively and quantitatively analyzed by HPLC to lead to the finding of 3,4-di-O-caffeoyquinic acid and 3-O-p-coumaroylquinic acid and their contents ranged over 2.72-4.47 mg/g and 8.97-23.26 mg/g, respectively. A cultivar Hacheong had the highest quantity of quinic acid derivatives. The peroxynitrite scavenging effect of the five cultivars (Jangsu, Gosina 27, Gopung, Yeolpungjeogchima, and Mipungjeogchugmyeon) were ranged over 7.45-8.26${\mu}g$/ml as $IC_{50}s$ while those of Hacheong and Mihong had less effect ($IC_{50}$ >10 ${\mu}g$/ml).

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.55-58
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• 1994

Agrobacterium tumefaciens LABA4404 harboring plant binary vector, pBI121, was used for genetic transformation of lettuce (Lactuca sativa t.). Cotyledon segments were infected with A. tumefaciens LBA4404 by cocultivation method and regenerated. Regenerated letture was subject to molecular analyses for integration into plant nuclear genome and expression of ${\beta}$-glucumnidase (GUS) gene. Southern and Northern blot analyses demonstrated that GUS gene was integrated into plant nuclear genome and expressed into its mRNA. The expression of GUS gene into its protein was confirmed by specetrophotometric assay of GUS activity.

• Molecules and Cells
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• v.24 no.2
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• pp.301-306
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• 2007

Tocopherols, essential components of the human diet, are synthesized exclusively by photosynthetic organisms. To increase tocopherol content by increasing total flux to the tocopherol biosynthetic pathway, genes encoding Arabidopsis homogentisate phytyltransferase (HPT/V-TE2) and tocopherol cyclase (TC/VTE1) were constitutively overexpressed in lettuce (Lactuca sativa L.). Total tocopherol content of the transgenic plants overexpressing either of the genes was increased by more than 2-fold mainly due to an increase in ${\gamma}$-tocopherol. However, chlorophyll content in the HPT/VTE2 and TC/VTE1 transgenic lines decreased by up to 20% and increased by up to 35%, respectively (P < 0.01). These results demonstrate that manipulation of the tocopherol biosynthetic pathway can increase or decrease chlorophyll content depending on the gene introduced.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.111-116
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• 2012

Nondestructive evaluation of seed viability is one of the highly demanding technologies for seed production industry. Conventional seed sorting technologies, such as tetrazolium and standard germination test are destructive, time consuming, and labor intensive methods. Near infrared spectroscopy technique has shown good potential for nondestructive quality measurements for food and agricultural products. In this study, FT-NIR spectroscopy was used to classify normal and artificially aged lettuce seeds. The spectra with the range of 1100~2500 nm were scanned for lettuce seeds and analyzed using the principal component analysis(PCA) method. To classify viable seeds from nonviable seeds, a calibration modeling set was developed with a partial least square(PLS) method. The calibration model developed from PLS resulted in 98% classification accuracy with the Savitzky-Golay $1^{st}$ derivative preprocessing method. The prediction accuracy for the test data set was 93% with the MSC(Multiplicative Scatter Correction) preprocessing method. The results show that FT-NIR has good potential for discriminating non-viable lettuce seeds from viable ones.

• Research in Plant Disease
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• v.25 no.4
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• pp.237-242
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• 2019

Severe damage on a greenhouse grown lettuce (Lactuca sativa L.) associated with Paratylenchus projectus is described for the first time. There were no marketable lettuce in entire greenhouse after three months of planting. Lettuce roots system appeared corky and most of feeder rootlets disappeared. Population densities of P. projectus were ranged from 320-11,600 nematodes per 100 ㎤ of soil. In an inoculation test in a greenhouse, P. projectus is proved as a causal agent of lettuce damage.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.435-439
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• 2000

Explants of lettuce (Lactuca sativa L.) were cocultured with A. tumefaciens LBA 4404 harboring ${\gamma}$-tocopherol methyltransferase (${\gamma}$-TMT) gene from Arabidopsis thaliana. These explants were transferred to MS medium supplemented with 50 mg/L kanamycin, 500 mg/L carbenicillin, 0.1 mg/L NAA and 0.5 mg/L BA. After 4 weeks, kanamycin resistant shoots were obtained from the explants on the selection medium. The putative transgenic shoots were transferred to rooting MS medium supplemented with 50 mg/L kanamycin and 250 mg/L carbenicillin. Stable incorporation of the Arabidopsis ${\gamma}$-TMT cDNA into lettuce genomic DNA was confirmed by PCR and Southern analysis. HPLC analysis showed that $\alpha$- to ${\gamma}$-tocopherol ratio increased over four fold in a transgenic lettuce line indicating successful expression of the transgenic Arabidopsis ${\gamma}$-TMT in lettuce.