• The Plant Pathology Journal
• /
• v.38 no.1
• /
• pp.1-11
• /
• 2022

Fusarium culmorum is one of the most important causal agents of root rot of wheat. In this study, 10 F. culmorum isolates were collected from farms located in five agro-ecological regions of Morocco. These were used to challenge 20 durum wheat genotypes via artificial inoculation of plant roots under controlled conditions. The isolate virulence was determined by three traits (roots browning index, stem browning index, and severity of root rot). An alpha-lattice design with three replicates was used, and the resulting ANOVA revealed a significant (P < 0.01) effect of isolate (I), genotype (G), and G × I interaction. A total of four response types were observed (R, MR, MS, and S) revealing that different genes in both the pathogen and the host were activated in 53% of interactions. Most genotypes were susceptible to eight or more isolates, while the Moroccan cultivar Marouan was reported resistant to three isolates and moderately resistant to three others. Similarly, the Australian breeding line SSD1479-117 was reported resistant to two isolates and moderately resistant to four others. The ICARDA elites Icaverve, Berghisyr, Berghisyr2, Amina, and Icaverve2 were identified as moderately resistant. Principal component analysis based on the genotypes responses defined two major clusters and two sub-clusters for the 10 F. culmorum isolates. Isolate Fc9 collected in Khemis Zemamra was the most virulent while isolate Fc3 collected in Haj-Kaddour was the least virulent. This work provides initial results for the discovery of differential reactions between the durum lines and isolates and the identification of novel sources of resistance.

• The Plant Pathology Journal
• /
• v.35 no.6
• /
• pp.623-634
• /
• 2019

Little known the connections between soybeans mitogen-activated protein kinase (MAPK) gene expression and the rhizomicrobiome upon invasion of the root pathogen Fusarium oxysporum. To address this lack of knowledge, we assessed the rhizomicrobiome and root transcriptome sequencing of wild and cultivated soybean during the invasion of F. oxysporum. Results indicated F. oxysporum infection enriched Bradyrhizobium spp. and Glomus spp. and induced the expression of more MAPKs in the wild soybean than cultivated soybean. MAPK gene expression was positively correlated with Pseudomonadaceae but negatively correlated with Sphingomonadaceae and Glomeraceae in both cultivated and wild soybean. Specifically, correlation profiles revealed that Pseudomonadaceae was especially correlated with the induced expression of GmMAKKK13-2 (Glyma.14G195300) and GmMAPK3-2 (Glyma.12G073000) in wild and cultivated soybean during F. oxysporum invasion. Main fungal group Glomeraceae was positively correlated with GmMAPKKK14-1 (Glyma.18G060900) and negatively correlated with GmRaf6-4 (Glyma.02G215300) in the wild soybean response to pathogen infection; while there were positive correlations between Hypocreaceae and GmMAPK3-2 (Glyma.12G073000) and between Glomeraceae and GmRaf49-3 (Glyma.06G055300) in the wild soybean response, these correlations were strongly negative in the response of cultivated soybean to F. oxysporum. Taken together, MAPKs correlated with different rhizomicrobiomes indicating the host plant modulated by the host self-immune systems in response to F. oxysporum.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.3
• /
• pp.205-215
• /
• 2004

The characteristic ratio assignment (CRA) method〔1〕 is new polynomial approach which allows to directly address the transient responses such as overshoot and speed of response time in time domain specifications. The method is based on the relationships between time response and characteristic ratios($\alpha_i$ ) and generalized time constant (T), which are defined in terms of coefficients of characteristic polynomial. However, even though the CRA can apply to developing a linear controller that meets good transient responses, there are still some fundamental questions to be explored. For the purpose of this, we have analyzed several sensitivities of a linear system with respect to the changes of coefficients itself and $\alpha_i$ of denominator polynomial. They are (i) the unnormalized root sensitivity : to determine how the poles change as $\alpha_i$ changes, and (ii) the function sensitivity to determine the sensitivity of step response to the change of o, and to analyze the sensitivity of frequency response as o, changes. As an other important result, it is shown that, under any fixed T and coefficient of the lowest order of s in denominator, the step response is dominantly affected merely by $\alpha_1, alpha_2 and alpha_3$ regardless of the order of denominator higher than 4. This means that the rest of the$\alpha_i$ s have little effect on the step response. These results provide some useful insight and background theory when we select $\alpha_i$ and T to compose a reference model, and in particular when we design a low order controllers such as PID controller.

• Korean Journal of Soil Science and Fertilizer
• /
• v.27 no.2
• /
• pp.136-146
• /
• 1994

To research the effect of chemotaxis of Rhizobia toward the root exudate on nitrogen fixing ability in soybean Rhizobia symbiosis system. Root exudate from seedlings of Glycine max. L was collected aseptic conditions. B. japonicum KCTC 2422 induced the formation of symbiotic nitrogen fixing nodules on the root of soybean plant and possessed motility and chemotaxis toward the 2mM proline. LPN-100 mutant was $Nod^-$, $Che^+$, and LPN-101 was $Che^-$, $Nod^+$ strains. Physiological properties of mutants were similar to parent strain. The crude root exudate was tested for its chemotactic ability using the capillary tube method. Chemotactic responses of RCR 3407 toward crude root exudate were 2.2, 2.6, 2.9, those of KCTC 2422 were 2.3, 2.9, 3.0, respectively. The crude root exudate was fractionated into neutral, cationic and anionic fractions. Chemotactic responses of KCTC 2422 was least with anionic fraction, most with neutral and intermediate with cationic fraction. B. japonicum KCTC 2422 was attracted by carbohydrates, amino acids and carboxylic acid. Carbohydrates and amino acids were good chemoattractants and carboxylic acids were intermediate chemoattractants. The peak concentration was $10^{-3}M$ for ribose, glucose, glutamine, aspartic acid and carboxylic acids, with exception of xylose, arabinose, tryptophan, which elicited maximum responses at $10^{-4}M$. The formation of nodules and nitrogenase activity of soybean inoculated with KCTC 2422 was determined in 7days after inoculation, and those of LPN-101 was detected in 15days after inoculation, but LPN-100 didn't form of nodules in soybean plants.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.322-322
• /
• 2017

To avoid drought stress under rainfed upland conditions, it is important for rice to efficiently utilize water at shallow soil layers supplied by rainfall, and access to water retained in deer soil layers. The root developmental characteristics of rice, which play important role in the adaptability to drought conditions, vary depending on the variety. Moreover, water availability for plant differs depending on the soil types that have different physical properties such as water holding capacity, permeability, capillary force, penetration resistance, etc. In this study, we evaluated growth and yield responses of rice varieties to various soil water deficit conditions under three different soil types. The experiment was conducted in a plastic greenhouse at the Kenya Agricultural and Livestock Research Organization-Mwea from October 2016 to January 2017. Two upland varieties (NERICA 1 and 4) and one lowland variety (Komboka) were grown in handmade PVC pots (15.2 cm diameter and 85.0 cm height) filled with three different types of soil collected from major rice-growing areas of the country, namely black cotton (BC), red clay (RC), and sandy clay (SC). Three watering methods, 1) supplying water only from the soil surface (W1), 2) supplying water only from the bottom of the pots (W2), and 3) supplying water both from the soil surface and the bottom of pots (W3), were imposed from 40 days after sowing to maturity. Soil water content (SWC) at 20, 40, and 60 cm depths was measured regularly. At the harvesting stage, aboveground and root samples were collected to determine total dry weight (TDW), grain yield, and root length at 0-20, 20-40, 40-60, and 60-80 cm soil layers. Irrespective of the watering methods, the greatest root development was obtained in RC, while that in BC was less than other two soils. In BC, the degree of yield reduction under W1 was less than that in RC and SC, which could be attributed to the higher water holding capacity of BC. In RC, the growth and yield reduction observed in all varieties under W1 was attributed to the severe drought stress. On the other hand, under W2, SWC at the shallow soil depth in RC was maintained because of its higher capillary force compared with BC and SC. As the result, growths and yields in RC were not suppressed under W2. In SC, deep root development was not promoted by W2 irrespective of the varieties, which resulted in significant yield losses. Under W1, the rice growth and yield in SC was decreased although shallow root development was enhanced, and the stomatal conductance was maintained higher than RC. It was suspected that W1 caused nutrients leaching in SC because of its higher permeability. Under rainfed conditions, growth and yield of rice can be strongly affected by soil types because dynamics of soil water conditions change according to soil physical properties.

• Journal of Bio-Environment Control
• /
• v.14 no.3
• /
• pp.190-195
• /
• 2005

This research was conducted to investigate the changes in soil chemical properties of root media as influenced by incorporation rate of a polyacryl amide hydrogel, Stocksorb C. The pH at 5 weeks after treatment in four root media such as peatmoss + vermiculite (1:1, v/v; PV), peatmoss + composted rice hull (1:1; PR), peatmoss + composted saw dust (1:1; PD) and peatmoss + composted pine bark (1:1; PB) containing STSB were in the range from 7.04 to 7.30, which was too high. Elevated incorporation rate of STSB resulted in increase of EC in soil solution of four root media with linear and quadratic response. The concentrations of $NH_4^+-N,\;NO_3^--N,\;PO_4-P^{3-},\;K^+,\;Ca^{2+}and\;Mg^{2+}$ in four kinds of root media increased as incorporation rates of STSB were elevated. But the $NO_3^-$-N concentrations in PS media were lower than those in other there root media tested. The Fe concentrations in PV, PR and PS media increased as incorporation rates of STSB were elevated, but those in PB medium did not show significant different. The concentrations of $Fe^{2+},\;Mn^{2+},\;Zn^{2+}and\;Cu^{2+}$ in PS media were higher than those in other three root media.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.4
• /
• pp.576-580
• /
• 2003

A 7-year-old male was refered to Department of Pediatric Dentistry, Wonkwang Dental Hospital for treatment of a traumatic injury to the teeth of the maxillary anterior region of the mouth. His right central incisor presented subluxation and root fracture, the left central incisor had suffered intrusive luxation and root fracture. The initial treatment involved reposition and fixation of the teeth with 0.5mm stainless steel wire and composite resin. The patient was submitted for clinical and radiographic fallow-up. After 4 years, radiographically the right central incisor seemed to be healed by hard tissue union and showed to be indistinct fracture line, intact lamina dura. The left central incisor radiographically was healed by interposition of bone and connective tissue and showed to be distinct horizontal fracture line separating the fragments, and pulp canal obliteration. In clinical examination, the teeth showed a normal response to elective pulp test, percussion and mobility test. Pulp survival after injuries appears to be dependent upon the type of luxation injury, age of patient, stage of root development and degree of dislocation. In this case, the two teeth with incomplete root formation were suffered different type of injury by trauma and has showed different healing aspect.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.194-198
• /
• 2005

Growth curves of Listeria monocytogenes in modified surimi-based imitation crab (MIC) broth were obtained by measuring cell concentration in MIC broth at different culture conditions [initial cell numbers, $1.0{\times}10^{2},\;1.0{\times}10^{3}\;and\;1.0{\times}10^{4}$, colony forming unit (CFU)/mL; temperature, 15, 20, 25, 37, and $40^{\circ}C$] and applied to Gompertz model to determine microbial growth indicators, maximum specific growth rate constant (k), lag time (LT), and generation time (GT). Maximum specific growth rate of L. monocytogenes increased rapidly with increasing temperature and reached maximum at $37^{\circ}C$, whereas LT and GT decreased with increasing temperature and reached minimum at $37^{\circ}C$. Initial cell number had no effect on k, LT, and GT (p > 0.05). Polynomial and square root models were developed to express combined effects of temperature and initial cell number using Gauss-Newton Algorism. Relative coefficients of experimental k and predicted k of polynomial and square root models were 0.92 and 0.95, respectively, based on response surface model. Results indicate L. monocytogenes growth was mainly affected by temperature and square root model was more effective than polynomial model for growth prediction.

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.415-422
• /
• 2010

Two leaf lettuces, chicory, endive, edible chrysanthemum, and pak-choi were hydroponically cultured under root restricted conditions in a deep flow technique system and their growth and nutritional values were investigated. Cylindrical plastic tubes with 100 mm height and diameters of 20, 25 or 30 mm were used for root restriction. Growth of all species was retarded by 25-95% as the roots zone was restricted. Pak-choi and edible chrysanthemum showed greater reduction in growth as compared with chicory and endive. Percent dry matter, C/N ratio, and contents of total ascorbic acid and total anthocyanin increased in the root restricted treatments. Contents of P and K decreased in the root restricted treatments, while contents of Mg, Fe, Mn, and Zn were not consistent among the tested species. Optimized root volumes to improve the nutritional values and to reduce the growth retardation varied depending on species of leafy vegetables. Tubes of ${\Phi}25mm{\times}100mm$ and ${\Phi}30mm{\times}100mm$ were suitable for chicory, endive and lettuce, and edible chrysanthemum and pak-choi, respectively. Results indicate that nutritional values of hydroponically-cultured leafy vegetables can be improved by root restriction.

• Food Science and Preservation
• /
• v.24 no.3
• /
• pp.413-420
• /
• 2017

This study was designed to examine the in vitro antioxidant and anti-inflammatory effects of red beet (Beta vulagaris) root. Red beet root was extracted using 70% ethanol and then fractionated sequentially with n-hexane, ethyl acetate and butanol. Antioxidative ability was evaluated by bioassays using total polyphenol contents and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid diammonium salt) radical scavenging activity. Ethyl acetate fraction of red beet root was best on total polyphenol contents ($37.02{\pm}0.37mg\;GAE/g$) and ABTS radical scavenging effects ($IC_{50}$ $42.9{\pm}9.5{\mu}g/mL$). For the anti-inflammatory activity in RAW264.7 cells, the hexane fraction showed the highest inflammatory effect. Dose response studies were performed to determine the inhibitory effect of hexane fraction of red beet root on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The hexane fraction of red beet root inhibited the NO and $PGE_2$ production and the protein level of iNOS and COX-2, and protein expression of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6 and $IL-1{\beta}$), in a dose-dependent manner. These results suggest that red beet root has considerable potential as a functional food ingredient with antioxidative and anti-inflammatory effects.