Publications by authors named "Younsig Kwak"

The Korean fir (), a native coniferous species of Korea, predominantly inhabits the subalpine zone. Recently, this species has experienced a significant population decline, primarily attributed to environmental changes in the subalpine zone driven by global warming. Efforts to prevent the extinction of the Korean fir are underway, with a predominant focus on abiotic factors contributing to its decline.

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Article Synopsis
  • The study explores "suppressiveness," where ongoing cropping reduces plant disease impact, particularly focusing on ginseng monoculture and its microbial dynamics before disease occurs.
  • Using long-term monoculture and advanced sequencing methods, researchers analyzed changes in soil microbiota, pathogen density, and disease rates, discovering that microbial communities decline before root rot disease manifests.
  • They identified key microbes that influence soil health and disease resistance, highlighting the importance of maintaining microbial diversity for sustainable agriculture and effective disease management.
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Aim: Fire blight, attributed to the bacterium Erwinia amylovora, significantly damages economically important crops, such as apples and pears. Conventional methods for managing fire blight involve the application of chemical pesticides, such as streptomycin and oxytetracycline. Nevertheless, apprehensions are increasing regarding developing antibiotic and pesticide-resistant strains, compounded by documented instances of plant toxicity.

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Ginsengs, widely acknowledged for their health-promoting properties, are predominantly grown for their roots, necessitating an extended cultivation period of a minimum of 4 to 6 years for maturation. The prolonged growth duration in a specific location makes ginseng plants susceptible to soil-borne ailments, such as root rot, leading to significant detrimental effects. Focusing on the crucial role of the plant microbial community in maintaining ginseng health, the study reveals that repeated and continuous cultivation leads to the collapse of the initial disease-suppressive rhizosphere community, resulting in severe root rot.

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Callose, a β-1,3-glucan plant cell wall polymer, regulates symplasmic channel size at plasmodesmata (PD) and plays a crucial role in a variety of plant processes. However, elucidating the molecular mechanism of PD callose homeostasis is limited. We screened and identified an Arabidopsis mutant plant with excessive callose deposition at PD and found that the mutated gene was α1-COP, a member of the coat protein I (COPI) coatomer complex.

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Soybean (Glycine max), a crucial global crop, experiences yearly yield reduction due to diseases such as anthracnose (Colletotrichum truncatum) and root rot (Fusarium spp.). The use of fungicides, which have traditionally been employed to control these phytopathogens, is now facing challenges due to the emergence of fungicide-resistant strains.

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Brown rot disease, caused by Monilinia spp., poses a significant threat to pome and stone fruit crops globally, resulting in substantial economic losses during pre- and post-harvest stages. Monilinia fructigena, M.

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The aim of this study was to investigate the regulation of lantipeptide production in Streptomyces globisporus SP6C4, which produces the novel antifungal lantipeptides conprimycin and grisin, and to identify the role of cytochrome P450 (P450) in tis regulation. To investigate the regulation of lantipeptide production, we created gene deletion mutants, including ΔP450, ΔtsrD, ΔlanM, ΔP450ΔtsrD, and ΔP450ΔlanM. These mutants were characterized in terms of their morphology, sporulation, attachment, and antifungal activity against Fusarium oxysporum.

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Fire blight disease, caused by the bacterial pathogen , has been a significant concern for over 50 countries worldwide. The efficacy of chemical pesticides currently available for disease control is limited. To address this issue, research is being conducted to explore environmentally friendly control methods, particularly biological control using beneficial microorganisms.

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ire blight disease, caused by Erwinia amylovora, is a devastating affliction in apple cultivation worldwide. Chemical pesticides have exhibited limited effectiveness in controlling the disease, and biological control options for treating fruit trees are limited. Therefore, a relatively large-scale survey is necessary to develop microbial agents for apple trees.

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Herein, we explored the potential of the apple's core microbiota for biological control of , which causes fire blight disease, and analyzed the structure of the apple's bacterial community across different tissues and seasons. Network analysis results showed distinct differences in bacterial community composition between the endosphere and rhizosphere of healthy apples, and eight taxa were identified as negatively correlated with , indicating their potential key role in a new control strategy against the pathogen. This study highlights the critical role of the apple's bacterial community in disease control and provides a new direction for future research in apple production.

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Ginseng is a popular medicinal herb with established therapeutic effects such as cardiovascular disease prevention, anticancer effects, and anti-inflammatory effects. However, the slow growth of ginseng due to soilborne pathogens has been a challenge for establishing new plantations. In this study, we investigated root rot disease associated with the microbiota in a ginseng monoculture model system.

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Article Synopsis
  • Endophyte bacteria form a mutualistic relationship with plants, aiding in growth and stress management.
  • L-glutamic acid enhances bacterial populations in tomato plants, promoting growth and colonization in response to salinity stress.
  • The study reveals L-glutamic acid's ability to mitigate salinity damage, though it has a limited effect on drought stress.
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The plant microbiota plays a crucial role in promoting plant health by facilitating the nutrient acquisition, abiotic stress tolerance, biotic stress resilience, and host immune regulation. Despite decades of research efforts, the precise relationship and function between plants and microorganisms remain unclear. Kiwifruit (Actinidia spp.

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Plant microbiota has influenced plant growth and physiology significantly. Plant and plant-associated microbes have flexible interactions that respond to changes in environmental conditions. These interactions can be adjusted to suit the requirements of the microbial community or the host physiology.

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Soybean is an important source of protein and for a wide range of agricultural, food, and industrial applications. Soybean is being affected by Xanthomonas citri pv. glycines, a causal pathogen of bacterial pustule disease, result in a reduction in yield and quality.

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Microalgae are photosynthetic cyanobacteria and eukaryotic microorganisms, mainly living in the water. In agriculture, numerous studies have been conducted to utilize microalgae as a biostimulant resource. has been known to be one such microalga that can promote plant growth by secretion of auxin or cytokinin hormone analogs.

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Orchids live with mycorrhizal fungi in mutualism. This symbiotic relationship plays an essential role in the overall life cycle of orchids from germination, growth, settlement, and reproduction. Among the 1000 species of the orchid, the Korean lady's slipper, , is known as an endangered species.

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Strawberries are a popular economic crop, and one of the major plantations and exporting countries is Korea in the world. The species complex (FOSC) is a soil-borne pathogen with genetic diversity, resulting in wilt disease in various crops. In Korea, strawberries wilt disease was first reported in the 1980s due to the infection of FOSC, causing significant economic damage every year.

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Background: Plants in nature interact with other species, among which are mutualistic microorganisms that affect plant health. The co-existence of microbial symbionts with the host contributes to host fitness in a natural context. In turn, the composition of the plant microbiota responds to the environment and the state of the host, raising the possibility that it can be engineered to benefit the plant.

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Erwinia amylovora causes fire blight, a devastating disease of apples and pears. Here, we report the complete genome sequence and annotation of E. amylovora strain TS3128, which was isolated from Anseong, South Korea, where fire blight first occurred in 2015, using the PacBio RS II system.

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Fire blight disease, caused by Erwinia amylovora, could damage rosaceous plants such as apples, pears, and raspberries. In this study, we designed to understand how E. amylovora affected other bacterial communities on apple rhizosphere; twig and fruit endosphere; and leaf, and fruit episphere.

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Soil is the major source of plant-associated microbes. Several fungal and bacterial species live within plant tissues. Actinomycetes are well known for producing a variety of antibiotics, and they contribute to improving plant health.

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