The Kunitz trypsin inhibitor (KTi) in soybean has several polymorphic types that are controlled by multiple alleles, which behave in a co-dominant fashion. Of these, Tia and Tib, which differ by nine amino acids, are the predominant types. In order to develop a single nucleotide amplified polymorphism (SNAP) marker for the classification of the predominant KTi types, Tia and Tib, and evaluate KTi activities by differing KTi type total 451 soybean mutant lines (M(12)-M(16) generation) were incorporated in this study. Among 451 soybean mutants, 144 and 13 mutant lines showed decreased and increased trypsin inhibitor activity when compared with the original cultivars, respectively. To identify the KTi type, we designed a SNAP marker. Among 451 mutant lines from 12 soybean cultivars and landraces, 8 mutant lines derived from cvs. Baekwoon, Paldal and Suwon115 showed a change in KTi type when compared with the original cultivars using the SNAP marker. Five mutant lines in Suwon115 changed from Tib to Tia, while two mutant lines derived from cv. Baekwoon and one mutant line derived from cv. Paldal were changed from Tia to Tib. These changes of KTi types were confirmed by sequencing of the KTi genes and non-denaturing polyacrylamide gel electrophoresis of the KTi proteins. To identify the effect of KTi activity based on the change in KTi type, we measured the KTi activity using the three cultivars and eight mutant lines that showed changes in KTi type. Two mutant lines (BW-1 and 7-2) derived from cv. Baekwoon and one mutant line (PD-5-10) from cv. Paldal that changed from Tia to Tib showed lower activity than the original cultivar. In cv. Suwon115, five mutant lines that changed from Tib to Tia showed higher activity than the original cultivar. These results indicate that the designed SNAP marker was capable of identifying the KTi type and that Tia activity was higher than Tib activity in soybean.

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The soybean Kunitz trypsin inhibitor (KTi) has several polymorphic variants. Of these, Tia and Tib, which differ by nine amino acids, are the two main types. In this study, differences in KTi proteome between Tia and Tib were investigated using three soybean cultivars and three mutant lines. Two cultivars, Baekwoon (BW) and Paldal (PD), and one mutant line, SW115-24, were Tia type, whereas one soybean cultivar, Suwon115 (SW115), and two mutant lines, BW-7-2 and PD-5-10, were Tib type. Protein from the six soybean lines was extracted and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), non-denaturing polyacrylamide gel electrophoresis (non-denaturing PAGE), and two-dimensional polyacrylamide gel electrophoresis (2-DE). By SDS-PAGE, there was no difference between soybean cultivars and mutant lines, except for SW115-24. Western blot analysis revealed that, in comparison with Tia, Tib type accumulated relatively low amounts of KTi. By non-denaturing PAGE, the three soybean lines of Tib type were characterized by slower mobility than the three soybean lines of Tia type. Zymography detected eight distinct zones of trypsin inhibitory activity among which Tia and Tib lacked the fifth and sixth zone, respectively. By two-dimensional native polyacrylamide gel electrophoresis (2-DN), the spots related to trypsin inhibitory activity showed different mobilities, whereas only one KTi (21.5 kDa) spot was resolved by 2-DE. By two-dimensional zymography (2-DZ), Tib showed a broader activity zone (pI 4-7) in comparison with Tia (pI 4-5). The results indicate that the genotypes with a different type of KTi present different proteomic profiles and trypsin inhibitory activities.

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Pre-ionization experiments with pure toroidal field have been carried out in VEST (Versatile Experiment Spherical Torus) to investigate the feasibility of direct XB mode conversion from perpendicular LFS (Low Field Side) injection for efficient pre-ionization. Pre-ionization plasmas are studied by measuring the electron density and temperature profiles with respect to microwave power and toroidal field strength, and 2D full wave cold plasma simulation using the COMSOL Multiphysics is performed for the comparison. It is experimentally figured out that exceeding the threshold microwave power (>3 kW), the parametric decay and localized collisional heating is observed near the UHR (Upper Hybrid Resonance), and the efficient XB mode conversion can be achieved in both short density scale length (Ln) and magnetic scale length (LB) region positioned at outboard and inboard sides, respectively. From the 2D full wave simulations, the reflection and tunneling of X-wave near the R-cutoff layer according to the measured electron density profiles are analyzed with electric field polarization and power flow. Threshold electric field and wave power density for parametric decay are evaluated at least more than 4.8 × 104 V/m and 100 W/cm2, respectively. This study shows that efficient pre-ionization schemes using direct XB mode conversion can be realized by considering the key factors such as Ln, LB, and transmitted wave power at the UHR. Application to Ohmic start-up experiment is carried out to confirm the effect of the pre-ionization schemes on tokamak plasma start-up in VEST.

The fast wave branch in lower hybrid resonance frequency range, especially higher than 2ωlh, has been proposed for the central or off-axis electron heating and current drive in higher density plasmas than the slow wave scheme. With a higher cutoff density for launching, efficient coupling between the antenna and plasma would be a priority issue for feasibility. The fast wave coupling characteristics with the wave frequency, gap size, and electron density profile of the Versatile Experiment Spherical Torus (VEST) device are investigated using a commercial full wave FEM solver, COMSOL. Maximum coupling between combline antenna and plasma is expected to be at ∼500 MHz with n∥∼4.5. The coupled power ranges from 90% to 60% in the gap size between 0.5 cm and 1.5 cm. The relative power fraction of the fast wave is larger than 80% at these conditions. The propagation and coupling power of the fast wave is crucially dependent on the plasma density window by launching and confluence densities. Initial experimental result with low power shows that measured coupling efficiency starts to increase as electron density in front of antenna attains the level of cutoff density for the fast wave propagation. It varies from 30% to 90% with the edge density evolution, which is consistent with the coupling simulation using the measured edge density profile. Coupling simulation verified in this study will make it possible to predict and analyze the coupling characteristics of future lower hybrid fast wave experiments.

ABSTRACT. Under certain circumstances, transposable elements (TE) can create or reverse mutations and alter the genome size of a cell. Sorghum (Sorghum bicolor L.) is promising for plant transposon tagging due to its small genome size and its low content of repetitive DNA. We developed a marker system based on targeted region amplification polymorphisms (TE-TRAP) that uses the terminal inverted repeats (TIRs) of transposons. A total of 3816 class 2 transposons belonging to the PIF/Harbinger family were identified from the whole sorghum genome that produced five primers, including eight types of TIRs. To define the applicability and utilization of TE-TRAP, we used 21 individuals that had been bred after ɤ-ray irradiation. In total, 31 TE- TRAP, 16 TD, and 21 AFLP primer combinations generated 1133, 223, and 555 amplicons, respectively. The percent polymorphic marker was 62.8, 51.1, and 59.3% for the TE-TRAP, TD, and AFLP markers, respectively. Phylogenetic and principal component analyses revealed that TE-TRAP divided the 21 individuals into three groups. Analysis of molecular variance suggested that TE-TRAP had a higher level of genetic diversity than the other two marker systems. After verifying the efficiency of TE-TRAP, 189 sorghum individuals were used to investigate the associations between the markers and the ɤ-ray doses. Two significant associations were found among the polymorphic markers. This TE-based method provides a useful marker resource for mutation breeding research.