• Journal of Plant Biotechnology
• /
• v.36 no.2
• /
• pp.124-129
• /
• 2009

In general, the root color of Codonopsis lanceolata is white, but red or blue-colored root is found at a low frequency in nature. Red or blue-colored roots have scarcity value, thus farmers wish to produce colored roots. The factors for determining the color of roots are unclear whether the color is controlled by genetically or simply by environmentally such as soil environment. Using in vitro culture system which is advantageous for setting of the same culture condition, we analyzed the physiological and morphological characteristics and genetic differences among red-, blue- and white lines of C. lanceolata. In the red colored roots, stems of in vitro cultured plantlet were colored in dark red pigment. Histological analysis revealed that the red pigment was accumulated in the outer cortex layer of the stem and determined as anthocyanin. Chlorophyll contents in red root lines were higher than those in white- and blue root lines. Plantlets from red roots were smaller in both shoot length and total leaf area than those from white- and blue roots. Genetic differences among the three different colored C. lanceolata were determined by RAPD (Randomly Amplified Polymorphic DNA) analysis. Each line of colored roots had clear DNA polymorphism. These results indicate that the occurrence of red- and blue colored roots in nature was determined by genetic factors rather than soil enviromental conditions.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.1
• /
• pp.71-78
• /
• 1984

The light quality obtained from sunlight by removing the spectral region below about 500 nm(blue light region) showed a remarkable effect on the growth of pepper. The physiological characteristics evaluated with the conventionally adopted indices at the vegetative stage revealed that the filtered sunlight improved and accelerated growth in general. In addition, the photosynthetic pigment level comprising chlorophylls, ${\beta}-carotene$ and 5 xanthophyll components as major pigments was increased significantly in the leaves grown under the orange-colored light. The increase of pigment content was prominent for every carotenoid component rather than for chlorophylls. The strong growth activity produced by the elected spectral quality for this work was properly demonstrated by the fruit yield ratio (filtered light/white light) which was found to be 1.35. Also confirmed was that removing the blue light region from solar radiation did not result in worsening of the food quality of matured pepper. The logic behind selection of the above light quality and some data presented was discussed on various photobiological aspects.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.4
• /
• pp.285-296
• /
• 2014

The impacts of high temperature and drought were studied on the seedlings of three families (superiorgangwon74, intermediate-gangwon77 and inferior-gangwon132) of P. densiflora which had been selected by the based on the growth indexes of 32-year-old. The seedlings were grown in controlled-environment growth chambers with combinations of four temperatures ($-3^{\circ}C$, $0^{\circ}C$, $+3^{\circ}C$ $+6^{\circ}C$; based on the monthly average for 30 years in Korea) and two water conditions (control, drought). The growth performance, photosynthetic parameters and photosynthetic pigment contents were measured at every 30 days under four temperatures and drought condition, and the end of each treatment. The superior family showed higher relative diameter at root collar growth rate and the dry weight than intermediate and inferior family in all treatments. Under elevated temperature and drought condition, growth rate was decreased, and seedlings showed lower growth rate than that of control in three families under low temperature. Photosynthetic rate, stomatal conductance and transpiration rate of three families decreased with the increase of temperature and drought condition, and that of seedlings under low temperature was lower than control. But under elevated temperature and drought condition, water use efficiency increased in three families. Photosynthetic pigment contents of leaves decreased under the increase of temperature and drought condition, but chlorophyll a/b ratio increased with the increase of temperature and drought condition in three families. The superior family showed higher total chlorophyll content than intermediate and inferior family in all treatments. In conclusion, P. densiflora is under changed temperature and drought condition, growth was decreased, seedlings more affected in elevated temperature than that of decreased temperature. The increase in monthly average temperature in Korea of more than $6^{\circ}C$, P. densiflora seedling growth in depending on region may decrease. In this study, the superior family(gangwon74) showed more excellent growth and physiological responses than intermediate (gangwon77) and inferior(gangwon132) family under changes temperature and drought.

• Journal of Plant Biotechnology
• /
• v.35 no.4
• /
• pp.329-335
• /
• 2008

Tocopherols are essential lipophilic antioxidant in human cells, while little is known about its function in plant tissues. To study the impact of composition and content of tocopherols on stress tolerance, tobacco (Nicotiana tabacum) was transformed with a construct containing a cDNA insert encoding $\gamma$-tocopherol methyltransferase ($\gamma$-TMT/VTE4) from perilla under the control of the cauliflower mosaic virus (CaMV) 35S promoter. The transgenic tobacco was confirmed by PCR and RT-PCR. The total content and composition of tocopherols in the transgenic lines were similar with wild type controls. However, chlorophyll-a and carotenoid content in the transgenic lines were increased by up to 45% (P<0.01) and 39% (P<0.02), respectively. Also, the over-expression of $\gamma$-TMT increased the salt stress tolerance in tobacco plants. These results demonstrate that over-expression of $\gamma$-TMT gene in tocopherol bio-synthetic pathway can increase salt stress tolerance and contents of chlorophyll-a and carotenoid in transgenic tobacco plants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.20 no.2
• /
• pp.71-77
• /
• 2015

High-Performance Liquid Chromatography (HPLC) is a widely used method for measuring the concentration of chlorophyll a as an indicator for estimating phytoplankton biomass and primary production and also for identifying carotenoids to determine phytoplankton composition. However, tissue grinding procedure requires a lot of time and experience in the analysis of multiple sample. Accordingly, we measured the concentrations of photosynthetic pigments before and after the grinding, in order to understand the grinding effects on the quantitative analysis of chlorophylls and carotenoids using samples from southwestern East Sea. When tissue grinding procedure was omitted, we found that Chl a concentrations were underestimated up to 45% in average. Also, concentrations of Zeaxanthin, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxanthin, biomarkers of pico and nano-size phytoplankton, were underestimated up to maximum 77~85% without grinding. We found that the smaller the phytoplankton, the bigger underestimation of their biomarker pigments concentration is likely to happen due to the incomplete extraction. Thus, tissue grinding procedure should be included for HPLC analysis in all cases, to prevent the underestimation of not only Chl a but also carotenoids pigments.

• ALGAE
• /
• v.33 no.1
• /
• pp.127-141
• /
• 2018

Low efficiency in microalgal biomass production was largely attributed to the low density of algal cell cultures. Though mutations that reduced the level of chlorophyll or pigment content increased efficiency of photon usage and thus the cell-culture density under high-illumination growth conditions (e.g., >$500{\mu}mol\;photon\;m^{-2}\;s^{-1}$), it was unclear whether algae could increase cell-culture density under low-illumination conditions (e.g., ${\sim}50{\mu}mol\;photon\;m^{-2}\;s^{-1}$). To address this question, we performed forward genetic screening in Chlamydomonas reinhardtii. A pool of >1,000 insertional mutants was constructed and subjected to continuous subcultures in shaking flasks under low-illumination conditions. Complexity of restriction fragment length polymorphism (RFLP) pattern in cultures indicated the degree of heterogeneity of mutant populations. We showed that the levels of RFLP complexity decreased when cycles of subculture increased, suggesting that cultures were gradually populated by high cell-culture density (HCD) strains. Analysis of the 3 isolated HCD mutants after 30 cycles of subcultures confirmed that their maximal biomass production was 50-100% higher than that of wild type under low-illumination. Furthermore, levels of chlorophyll content in HCD mutant strains were similar to that of wild type. Inverse polymerase chain reaction analysis identified the locus of insertion in two of three HCD strains. Molecular and transcriptomic analyses suggested that two HCD mutants were a result of the gain-of-function phenotype, both linking to the abnormality of mitochondrial functions. Taken together, our results demonstrate that HCD strains can be obtained through continuous subcultures under low illumination conditions.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.3
• /
• pp.503-510
• /
• 2016

The accumulation (internal and superficial distribution) of magnesium ions (Mg²⁺) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg²⁺ (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg²⁺ were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg²⁺ uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg²⁺ concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg²⁺ removal from the medium was observed. Of the total Mg²⁺ present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg²⁺ were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg²⁺ bioaccumulation in C. vulgaris, which was consistent with the experimental data.

• Journal of Photoscience
• /
• v.8 no.1
• /
• pp.1-7
• /
• 2001

The deteriorative effect of ultraviolet-B(UV-B) radiation on photosynthesis was assessed by the simultaneous measurement of O$_2$ evolution and chlorophyll(Chl) fluorescence in green pepper. UV-B was given at the intensity of 1 W$.$m$\^$-2/, a dosage often encountered in urban area of Seoul in Korea, to detached leaves. Both Pmax and quantum yield of O$_2$ evolution was rapidly decreased, in a parallel phase, with increasing time of UV-B treatment. Chl fluorescence parameters were also significantly affected. Fo was increased while both Fm and Fv were decreased. Photochemical efficiency of PSII(Fv/Fm) was also declined, although to a lesser extent than Pmax. Both qP and NPQ were decreased similarly with increasing time of UV-B treatment. However, PS I remained stable. The addition of lincomycin prior to UV-B treatment accelerated the decline in Fv/Fm to some extent, suggesting that D1 protein turnover may play a role in overcoming the harmful effect of UV-B. The amount of photosynthetic pigments was less affected than photosynthetic response in showing decline in Chl a and carotenoids after 24 h-treatment. Presumptive flavonoid contents, measured by changes in absorbance at 270 nm , 300 nm and 330nm, were all increased by roughly 50% after 8 h-treatment. Among antioxidant enzymes, activities of catalase and peroxidase were steadily increased until 12h of UV-B treatment whereas ascorbate perxidase, dehydroascorvate reductase and glutathione reductase did not show any significant change. The results indicate that deteriorative effect of UV-B on photosynthesis precedes the protection exerted by pigment synthesis and antioxidant enzymes.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.69 no.1
• /
• pp.1-14
• /
• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.1
• /
• pp.48-55
• /
• 2009

Seasonal variations of microalgal biomass and community composition in both the sediment and the seawater were investigated by HPLC pigment analysis in an estuarine muddy sandflat of Gwangyang Bay from January to November 2002. Based on the photosynthetic pigments, fucoxanthin, diadinoxanthin, and diatoxanthin were the most dominant pigments all the year round, indicating that diatoms were the predominant algal groups of both the sediment and the seawater in Gwangyang Bay. The other algal pigments except the diatom-marker pigments showed relatively low concentrations. Microphytobenthic chlorophyll ${\alpha}$ concentrations in the upper layer (0.5 cm) of sediments ranged from 3.44 (March at the middle site of the tidal flat) to 169 (July at the upper site) mg $m^{-2}$, with the annual mean concentrations of $68.4{\pm}45.5,\;21.3{\pm}14.3,\;22.9{\pm}15.6mg\;m^{-2}$ at the upper, middle, and lower tidal sites, respectively. Depth-integrated chlorophyll ${\alpha}$ concentrations in the overlying water column ranged from 1.66 (November) to 11.7 (July) mg $m^{-2}$, with an annual mean of $6.96{\pm}3.04mg\;m^{-2}$. Microphytobenthic biomasses were about 3${\sim}$10 times higher than depth-integrated phytoplankton biomass in the overlying water column. The physical characteristics of this shallow estuarine tidal flat, similarity in taxonomic composition of the phytoplankton and microphytobenthos, and similar seasonal patterns in their biomasses suggest that resuspended microphytobenthos are an important component of phytoplankton biomass in Gwangyang Bay. Therefore, considering the importance of microphytobenthos as possible food source for the estuarine benthic and pelagic consumers, a consistent monitoring work on the behavior of microphytobenthos is needed in the tidal flat ecosystems.