• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.332-340
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• 2016

Seed size traits are controlled by multiple genes in crops and determine grain yield, quality and appearance. However, the molecular mechanisms controlling the size of plant seeds remain unclear. We performed functional analysis of BrPATL4 encoding Sec14-like protein to determine the genetic architecture of seed size, shape and their association analyses. We used 60 $T_3$ transgenic rice lines to evaluate seed length, seed width and seed height as seed size traits, and the ratios of these values as seed shape traits. Pleiotropic effects on general architecture included small seed size, erect panicles, decreased grain weight, reduced plant height and increased sterility, which are common to other mutants deficient in gibberellic acid (GA) biosynthesis. To test whether BrPATL4 overexpression is deleterious for GA signal transduction, we compared the relative expression of GA related gene and the growth rate of second leaf sheath supplied with exogenous $GA_3$. Overexpression of BrPATL4 did not affect GA biosynthesis or signaling pathway, with the same response shown under GA treatment compared to the wild type. However, the causal genes for the small seed phenotype (D1, SRS1, and SRS5) and the erection of panicles showed significantly decreased levels in mRNA accumulation compared to the wild type. These results suggest that the overexpression of BrPATL4 can control seed size through the suppression of those genes related to seed size regulation. Although the molecular function of BrPATL4 is not clear for small seed and erect panicles of BrPALT4 overexpression line, this study provides some clues about the genetic engineering of rice seed architecture.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.75-83
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• 2013

The present study was examined seed germination and growth characteristics of Cynanchum wilfordii under the following conditions such as soaking temperature, concentrations of $GA_3$, trays and soil types, and shading conditions. In seed pre-treatment, germination rate was the highest at 93% when soaked in 100 ppm $GA_3$ at $20^{\circ}C$ and seedling growth was best in 50 plug cell tray. Physiological quality was best in the condition in which seeds were treated with 10 ppm $GA_3$ at $20^{\circ}C$. Taking into consideration the seedling growth, their physiological quality as well as economical aspects, seedlings with plant height (over 10 cm) and root length (over 10 cm) were grown vigorously 30-45 days after the seeds were sown in mid-April in TKS, TKS+perlite and TKS+rice hull of 128 or 200 plug cell tray.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.35-40
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• 2003

In this study we investigated the effect of gametocides on the number of larger-sized pollen in anther, and also induced callus from the anther culture of Zoysia japonica Steud. Before culturing, we have observed pollens in anther through fluorescence and electron microscopes to know pollen dimorphism. There were two types of pollens observed. One type (30-36 ${\mu}{\textrm}{m}$ in diameter) consisted of vacuolated, larger-sized pollens and the other (15-20 ${\mu}{\textrm}{m}$ in diameter) smaller-sized ones with dense cytoplasm and plenty of amyloplasts. Within few hours, all the smaller-sized pollens were dead, while larger-sized ones were viable for one or two days. To induct larger-sized pollens, various gametocides were leaf-sprayed on three booting stages cultured under 4$0^{\circ}C$ /15$^{\circ}C$ (day/night) before anther culturing. Number of these larger pollens were few (less than 1%) in anther without spraying gametocides. GA$_3$increased the number of larger-sized pollens when applied at mid-booting stage. GA$_3$ with 50 mg/L treatment caused the highest percentage (25.4%) of the larger-sized pollen. Anthers with GA$_3$ treatment were only produced calli on AA medium (modified B$_{5}$+8.0 mg/L 2,4-D ＋0.2 mg/L kinetin), but callus formation was quite low (less than 1%).).

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.201-206
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• 1984

In order to obtain an easy and effective scarification method for stimulating the seed germination of Korean lawn grass (Zoysia japonica Steud.), sodium hypochlorite (SH), which is used as a commercial bleach and a seed disinfestant, was tested as a chemical scarifier instead of potassium hydroxide (KOH). 1. Scarification with 4% SH for 2 hours followed by 8-hour water-rinse stimulated seed germination more effectively compared to generalized scarification method by KOH treatment. 2. The degree of stimulating seed gemination was different by the various water-rinsing time after SH treatment, but the optimum rinsing time was about 4 to 8 hours. 3. GA treatment after SH scarification stimulated seed germination. However, the stimulation effect of GA was not showed in non-scarified control. 4. SH treatment significantly decreased the percentage of the infection of microflora in seed samples compared to KOH treatment. 5. Under practical seed scarification conditions for stimulating germination of Korean lawn grass seed. SH may have advantages over KOH with respect to ease of preparing, securing and handling.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.323-330
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• 2021

Zygotic embryo culture was performed to propagate evergreen oak, Quercus myrsinifolia, which has recalcitrant seeds and is difficult to propagate by cuttings. Zygotic embryos appeared in WPM medium after 14 days, and after 56 days, they developed into complete plants with cotyledons and roots. The medium suitable for zygotic embryo culture was 1/4 WPM medium, showing a shoot growth of 2.43 cm and root growth of 8.7 cm after 8 weeks of culture. As a result of investigating the effect of GA₃ on the growth of plants germinated from zygotic embryos through GA₃ treatment, the best growth was shown in 0.5 mg/l GA₃ treatment. The in vitro rooting and growth of IBA-treated zygotic embryo-derived plants were good in the 0.5 mg/l IBA treatment and rooting and shoot growth were not observed at higher concentrations. And the callus induction rate also increased as the concentration of IBA increased. Plants grown in vitro were transferred to a plastic pot containing artificial soil and acclimatized in a greenhouse for about 4 weeks, resulting in more than 90% survival. As a result of this study, the zygotic embryo culture method was confirmed to be effective for mass propagation of Q. myrsinifolia. The results of this study are expected to contribute significantly to the mass propagation of elite Q. myrsinifolia.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.1-13
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• 2020

This study was designed to evaluate the in vitro and in vivo effects of reductive acetogens isolated from ruminants on methane mitigation, and milk performance, respectively. Four acetogens, Proteiniphilum acetatigenes DA02, P. acetatigenes GA01, Alkaliphilus crotonatoxidans GA02, and P. acetatigenes GA03 strains were isolated from ruminants and used in in vitro experiment. A control (without acetogen) and a positive group (with Eubacterium limosum ATCC 8486) were also included in in vitro experiment. Based on higher acetate as well as lower methane producing ability in in vitro trial, P. acetatigenes GA03 was used as inoculum for in vivo experiment. Holstein dairy cows (n = 14) were divided into two groups viz. control (without) and GA03 group (diet supplied with P. acetatigenes GA03 at a feed rate of 1% supplementation). Milk performance and blood parameters were checked for both groups. In in vitro, the total volatile fatty acids and acetate production were higher (p < 0.05) in all 4 isolated acetogens than the control and positive treatment. Also, all acetogens significantly lowered (p < 0.05) methane production in comparison to positive and control groups however, GA03 had the lowest (p < 0.05) methane production among 4 isolates. In in vivo, the rate of milk yield reduction was higher (p < 0.05) in the control than GA03 treated group (5.07 vs 2.4 kg). Similarly, the decrease in milk fat was also higher in control (0.14% vs 0.09%) than treatment. The somatic cell counts (SCC; ×10³/mL) was decreased from 128.43 to 107.00 in acetogen treated group however, increased in control from 138.14 to 395.71. In addition, GA03 increased blood glucose and decreased non-esterified fatty acids. Our results suggest that the isolated acetogens have the potential for in vitro methane reduction and P. acetatigenes GA03 strain could be a candidate probiotic strain for improving milk yield and milk fat in lactating cows with lowering SCCs.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.242-246
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• 1977

In the barly coleptile sections treated with either $1{\times}10^{-5}M$ abscisic acid (ABA) or $1{\times}10^{-5}M$ gibberellic acid (GA), the time course changes of ribonuclease (RNase) activity and ribonucleic acid (RNA) profiles were studied. The results may be summarized as follows: 1. While GA suppressed RNase activity, ABA activated it. 2. High level of s-RNA and low level of r-RNA compared with normal plant sections in hormone-untreated coleoptiles seemed to be the results of increased RNase activity in the incubation period. 3. While GA retarded the decomposition of r-RNA, ABA activated it and the results seemed to be related with RNase activity. 4. GA activated the synthesis of RNA-DNA component, and ABA suppressed it. 5. Increase in the amount of s-RNA with the treatment of ABA may be due to the decomposition of r-RNA.

• Korean Journal of Plant Resources
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• v.22 no.3
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• pp.236-241
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• 2009

Dracocephalum argunense Fischer ex Link (Labiatae) is a perennial herbaceous plant used as valuable materials for ornamentals, honey production, and pharmaceutics. Since seed germination of this species was quite difficult, present studies were conducted to improve the germination rate by subjecting the seeds to various environmental conditions (temperature and light) and treatments (scarification, priming and seed coating). Optimum temperature for adequate germination was 20$^{\circ}C$ though it ranged from 15$^{\circ}C$ to 25$^{\circ}C$, and low temperature treatment improved germination rate. Light was required for higher germination rate in this species. The scarification of seeds resulted in much higher germination, especially by the physical treatment with sandpaper or chemical treatment with sulfuric acid for 30 seconds. Various primers with different concentrations were treated on the seeds and it was demonstrated that low temperature enhanced germination rate, regardless of kinds and concentrations of the primers. Three treatment combinations of the primers, 0.5 mM $GA_{3}$ treated for 48 hours, 0.5 mM IAA for 24 hours, and 1.0 mM IAA for 24 hours, increased the seed germination rate profoundly. Soaking treatment of inorganic salts, $KNO_{3}$ and $KH_{3}PO_{4}$, promoted germination when seeds were subjected to low temperature. Water soluble primers such as sucrose at 0.5 and 3% concentration and solid primer talc powder were effective in enhancing germination rate.

• Journal of IKEEE
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• v.11 no.4
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• pp.152-157
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• 2007

AlGaN/GaN high electron mobility transistors (HEMTs) were fabricated and the effect of ${N_2}O$ plasma on the electrical characteristics of the devices was investigated. The HEMT exposed to ${N_2}O$ plasma formed by 40 W of RF power in a chamber with pressure of 20 mTorr at a temperature of $200^{\circ}C$, exhibited a reduction of gate leakage current from 246 nA to 1.2 pA by 10 seconds treatment. The current between the two isolated active regions reduced from 3 uA to 7 nA and the sheet resistance of the active layer was lowered also. The variations of electrical characteristics for HEMT were occurred within a short time expose of 10 seconds and the successive expose did not influence on the improvements of gate leakage characteristics and conductivity of the active region. The reduced leakage current level was not varied by successive $SiO_2$ deposition and its removal. The transconductnace and drain current of AlGaN/GaN HEMTs were increased also by the expose to the ${N_2}O$ plasma.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.29-34
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• 1994

The possibility that DNA could move out of the single cells isolated from geranium (Pelargonium zonale hybrids, 'PintoScarlet') callus was determined by the elechophoretic DNA analysis after treatment of low pH, various concentrations of KNO$_3$, 2,4-D, and GA$_3$ followed by the centrifugal force, all of which are hewn to and the physico-chemical properties of the cell wall. The centrifugal force of l,800 xg was need for DNA migration after the above treatment, but 7k300 xg was required without the treatments. In this experiment the optimum concentration (300 mg/L) of sodium dodecyl sulfate (SDS) used as an anion detergent to collect the negatively charged DNA was very critical not to damage the cell wall It can be concluded that the centrifugal force played a key role for the DNA migration through the cell wall, and the treatments of low pH (4.0), 0.5% KNO$_3$, 1.5 mg/L GA$_3$and 1mg/L 2,4-D further increased the DNA migration.