• Korean Journal of Plant Resources
• /
• v.11 no.2
• /
• pp.195-201
• /
• 1998

Some morphological character were surveyed and PR-proteinases were induced and characterized from Lilium formosanum Wallace endeimc to Cheju island . Its flower characters were similar to those of white trumpet lilies(Lilium longiflorum Thunb) although its flowering period was later than that of white trumpet lilies and it hadd a wide range of variation among individuals. Six PR-proteinases(II-2, III-1, III-2, IV-1, IV-2 and V) were induced from bulbs by 2.5mM salicylic acid and almost excreted into the intercellular spaces. These PR-proteinases were strongly activated by Ca 2+, , whereas they were strongly inhibited by Cu2+ Co2+ and Fe2+ . Three PR proteinases(II-2, IV-1 and IV-2) were strongly inhibited by 1, 10 -phenanthroline, indicating that these enzymes are metallo-proteinases. Three PR-proteinases(III-1, III-2 and V) had a high sensitivity to PMSF and required $\beta$-mercaptoethanol for their activities. These results indicate that these proteinases are cysteine proteinases.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.27 no.4
• /
• pp.241-248
• /
• 2007

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. By using mRNA differential display, we isolated a cytokinine-inducible cDNA encoding pathogenesis-related (PR) 4 from Arabidopsis amp1 mutant. The full-length PR4 cDNA, designated AtPR4, contains an open reading frame of 212 amino acids with calculated molecular mass of 22,900 Da and isoelectric point (pI) of 7.89. Genomic DNA blotting showed that the Arabidopsis genome has one copy of AtPR4. AtPR4 mRNA was induced by cytokinin and NaCl, but decreased by SA or JA treatment. PR proteins are induced in response to pathogen attack. Thus the AtPR4 gene isolated in this study may be a useful candidate for genetic engineering of forage crops for increased tolerance against pathogen.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.5
• /
• pp.113-119
• /
• 2010

In this paper, the considered cognitive radio system has a pair of PT-PR and a pair of ST-SR. In first time slot(1 Phase), PT broadcast signal $x_p$ to PR, ST and SR. Then, each receivers(PR, ST, SR) decode received signal $x_p$. In second time slot(2 Phase), ST combine decoded signal ${x_p}^{\prime}$ and signal $x_s$, and it broadcast combined signal to PR and SR. PR and SR decode combined signal. At this time, PR can achieve diversity gain, due to using MRC, it combine 'received and decoded signal ${x_p}^{\prime}$ at 1 phase' and 'detected signal $x_p$ at 2 phase'. SR use linear combining technique and it can obtain $x_s$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.1
• /
• pp.68-73
• /
• 2024

In this study, the praseodymium-doped yttrium phosphate (YPO₄:Pr³⁺) powder, which is well known for its high luminescent efficiency, and long life in the UV range, was synthesized with various content ratios of Pr₆O₁₁ and calcination temperature. Crystal structure and luminescent properties of various phosphor powders based on different concentrations and calcination conditions were characterized by XRD (X-Ray Diffraction) and PL (photoluminescence) spectrometers. From the XRD analysis, the structure of YPO₄:Pr³⁺ which is calcinated at 1,200℃ was stable tetragonal phase and crystal size was calculated about 25 nm by Scherrer equation. PL emission of YPO₄:Pr³⁺ with a different content ratio of Pr₆O₁₁ by excitation λ_exc=250 nm shows that 0.75 mol% phosphor powder has maximum PL intensity and PL decreases with the increase of the ratio of Pr₆O₁₁ up to 1.25 mol% which is caused by changes of crystallinity of phosphor powders. With increasing dopant ratio, photo-luminescence Emission decreases due to Concentration quenching, which is commonly observed in phosphors. Currently, 0.75 mol% is considered the optimal doping concentration. A hybrid ultraviolet-emitting device incorporating YPO₄:Pr³⁺ fluorescent material with plasma discharge was fabricated to enhance UV germicidal effects while minimizing ozone generation. UV emission from the plasma discharge device was shown at about 200 nm and 350 nm which caused additional emission of the regions of 250 nm, 315 nm, and 370 nm from the YPO₄:Pr³⁺ phosphor.

• Journal of Oral Medicine and Pain
• /
• v.15 no.1
• /
• pp.55-60
• /
• 1991

After dividing 372 Korean people of 47 different family names into 307 people of 28 indigenous family name groups and 65 people of 19 immigrated family name groups and investigating Pr. Db, Pa gene frequency of each family name groups based on phenotype of parotid saliva character the author have got following conclusions. 1. The gene frequencies of indigenous family name groups were Pr1=0.686, Pr2=0.314, Pr gene frequencies of immigrated family name groups were Pr1=0.7, Pr2=0.3. 2. The gene frequencies of indigenous family name groups were Db==0.021, Db-=0.979, Pr gene frequencies of immigrated family name groups were Db+=0.023, Db-=0.977. 3. The gene frequencies of indigenous family name groups were Pa+=0.248, Pa-=0.752, Pr gene frequencies of immigrated family name groups were Pa+=0.206, Pa-=0.794. 4. The Pr gene frequencies of immigrated family name groups were in the middle of those of Chinese people and indigenous people groups. 5. There was no significant difference of Db gene frequencies between indigenous and immigrated family name groups. 6. Pa gene frequencies of immigrated family name groups were similar to those of Chinese people.

• Journal of the Korean Magnetics Society
• /
• v.4 no.2
• /
• pp.126-129
• /
• 1994

In order to invetigate the effect of Pr additive on the magnetostriction of amorphous Fe-B alloys, amorphous $Fe_{86-x}B_{14}Pr_{x}(2{\leq}x{\leq}8\;at.%)$ alloys were prepared by a rapid solidification process. As the Pr content increased in the as-prepared amorphous $Fe_{84}B_{14}Pr_{2}$ alloy annealed at $300^{\circ}C$ for 2 hr increased to 70 ppm. Ac power loss and permeability$(f=50\;kHz,\;B_{m}=0.1\;T)$ of the annealed amorphous $Fe_{84}B_{14}Pr_{2}$ alloy were 15 W/kg and $5.5{\times}10^{3}$, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.5
• /
• pp.422-426
• /
• 2006

[ $Sr_xCa_{(1-x)}TiO_3$ ] red phosphors doped with Pr(0.13 mol%) and Al(0.23 mol%) were synthesized by solid state reaction method. Change of crystal structure occurred in $Sr_xCa_{(1-x)}TiO_3:Pr,Al$ phosphors with increasing value of x. Green and red luminescence were observed from $SrTiO_3:Pr,Al$ phosphors at low temperature. However, only red luminescence in the case of $CaTiO_3:Pr,Al$ phosphors was measured at low temperature. The main cause of green luminescence was explained by the bandgap reduction.

• Journal of Life Science
• /
• v.25 no.1
• /
• pp.37-43
• /
• 2015

We have investigated the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), indole-3-acetic acid (IAA) and methyl jasmonate (MeJA) on the development of aerenchyma in the primary root of maize (Zea mays). Because plant hormones affected the longitudinal organization of the primary root, we need an indicator to direct the positions for comparison between control and hormone-treated roots. Therefore, the zones of the maize primary root were categorized as PR25, PR50 and PR75, where each value indicates the relative position between the root tip (PR0) and the base (PR100). Aerenchyma was not observed at PR25 and PR50 and rarely found at PR75 in the cortex of control roots. The aerenchymal area at PR75 increased in the presence of the ethylene precursor ACC or a natural auxin IAA. On the other hand, MeJA differentially acted on non-submerged and submerged roots. Exogenously applied MeJA suppressed the aerenchyma formation in non-submerged roots. When the primary root was submerged, aerenchymal area expanded prominently. The submergence-induced aerenchyma formation was amplified with MeJA. Lateral root primordia have been known to inhibit aerenchymal death of surrounding cells. All the three hormones stimulating aerenchyma formation as described above did not restore the inhibition caused by lateral root primordia, suggesting that the inhibitory step regulated by lateral root primordia can be located after hormonal signaling steps.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.11
• /
• pp.1495-1502
• /
• 2014

Metarhizium anisopliae is a widely studied model to understand the virulence factors that participate in pathogenicity. Proteases such as subtilisin-like enzymes (Pr1) and trypsin-like enzymes (Pr2) are considered important factors for insect cuticle degradation. In four M. anisopliae strains (798, 6342, 6345, and 6347), the presence of pr1 and pr2 genes, as well as the enzymatic activity of these genes, was correlated with their virulence against two different insect pests. The 11 pr1 genes (A, B, C, D, E, F, G, H, I, J, and K) and pr2 gene were found in all strains. The activity of individual Pr1 and Pr2 proteases exhibited variation in time (24, 48, 72, and 96 h) and in the presence or absence of chitin as the inductor. The highest Pr1 enzymatic activity was shown by strain 798 at 48 h with chitin. The highest Pr2 enzymatic activity was exhibited by the 6342 and 6347 strains, both grown with chitin at 24 and 48 h, respectively. Highest mortality on S. exigua was caused by strain 6342 at 48 h, and strains 6342, 6345, and 6347 caused the highest mortality 7 days later. Mortality on Prosapia reached 30% without variation. The presence of subtilisin and trypsin genes and the activity of these proteases in M. anisopliae strains cannot be associated with the virulence against the two insect pests. Probably, subtilisin and trypsin enzyme production is not a vital factor for pathogenicity, but its contribution is important to the pathogenicity process.

• The Plant Pathology Journal
• /
• v.21 no.3
• /
• pp.195-206
• /
• 2005

Spatial and temporal expression of pathogenesis-related (PR) gene and proteins has been recognized as inducible defense response in pepper plants. Gene expression and/or protein accumulation of PR-1, $\beta-1,3-glucanase$ and chitinase was predominantly found in pepper plants during the inoculations by Xanthomonas campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum coccodes. PR-1 and chitinase genes were also induced in pepper plants in response to environmental stresses, such as high salinity and drought. PR-1 and chitinase gene expressions by biotic and abiotic stresses were regulated by their own promoter regions containing several stress-related cis-acting elements. Overexpression of pepper PR-1 or chitinase genes in heterogeneous transgenic plants showed enhanced disease resistance as well as environmental stress tolerances. In this review, we focused on the putative function of pepper PR-1, $\beta-1,3-glucanase$ and chitinase proteins and/or genes at the biochemical, molecular and cytological aspects.