• The Plant Pathology Journal
• /
• 제37권4호
• /
• pp.396-403
• /
• 2021

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. Limited studies on the understanding of the microbial community of apples and changes the community structure by occurrence of the fire blight disease were conducted. As result of these experiments, the infected trees had low species richness and operational taxonomic unit diversity when compared to healthy trees. Rhizospheric bacterial communities were stable regardless of infection. But the communities in endosphere and episphere were significanlty affected by E. amylovora infection. We also found that several metabolic pathways differ significantly between infected and healthy trees. In particular, we observed differences in sugar metabolites. The finding provides that sucrose metabolites are important for colonization of E. amylovora in host tissue. Our results provide fundamental information on the microbial community structures between E. amylovora infected and uninfected trees, which will contribute to developing novel control strategies for the fire blight disease.

• 식물병연구
• /
• 제30권2호
• /
• pp.165-175
• /
• 2024

구상나무(Abies koreana)는 한국의 고유종이지만 기후 변화로 인한 심각한 개체수 감소 현상이 일어나고 있다. 구상나무의 보전을 위한 다양한 연구가 기존에 진행되었지만 구상나무와 근권 세균 군집의 상관관계에 대한 연구는 비교적 미진한 편이기 때문에 추가적인 연구 진행이 필요하다. 식물의 근권 미생물 군집을 구성하는 일부 세균은 식물이 수분, 양분 등이 부족한 환경에서 살아남을 수 있게 돕는다. 또한 계절 변화에 의한 급격한 환경 변화에 대한 식물의 적응력을 향상시켜 줄 가능성이 있다. 본 연구에서는 이러한 세균 군집이 구상나무의 근권에 존재하거나 구상나무의 서식지 유형(자생지, 대체서식지, 고사지, 비재배토양)과 계절 변화(4월, 6월, 9월, 11월)에 따른 군집 구조의 차이가 발생하는지 파악하기 위해 세균의 16S rRNA V4 영역을 대상으로 한 metagenome amplicon sequencing을 진행하였다. 그 결과 우리는 구상나무와 매우 특이적으로 상호작용하는 근권 세균 군집이나 특정 분류군은 찾을 수 없었지만 구상나무 비재배토양에 비해서 구상나무 자생지의 근권 세균 군집이 계절 변화에 의한 변동성이 적게 나타난다는 사실을 알아냈다. 이러한 결과는 구상나무의 근권의 환경이 비재배토양에 비해 상대적으로 안정하다는 것을 보여준다. 그러나 구상나무와 명확하게 상호작용하는 세균 군집이나 분류군을 찾을 수 없었기 때문에 세균 군집 이외의 진균과 같은 기타 근권 미생물 군집들에 대한 추가 연구의 필요성이 제시된다.

• The Plant Pathology Journal
• /
• 제38권5호
• /
• pp.425-431
• /
• 2022

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. In addition, it can be modified to suit microbiota structure or fixed by the host condition. However, no technology is realized yet to control mechanically manipulated plant microbiota structure. Here, we review step-by-step plant-associated microbial partnership from plant growth-promoting rhizobacteria to the microbiota structural modulation. Glutamic acid enriched the population of Streptomyces, a specific taxon in anthosphere microbiota community. Additionally, the population density of the microbes in the rhizosphere was also a positive response to glutamic acid treatment. Although many types of research are conducted on the structural revealing of plant microbiota, these concepts need to be further understood as to how the plant microbiota clusters are controlled or modulated at the community level. This review suggests that the intrinsic level of glutamic acid in planta is associated with the microbiota composition that the external supply of the biostimulant can modulate.

• Journal of Microbiology and Biotechnology
• /
• 제33권10호
• /
• pp.1299-1308
• /
• 2023

Carya cathayensis is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in C. cathayensis result in reduced yields and serious economic losses. Moreover, while soil bacterial communities play a crucial role in plant health and are associated with plant disease outbreaks, their diversity and composition in C. cathayensis are not clearly understood. In this study, Proteobacteria, Acidobacteria, and Actinobacteria were found to be the most dominant bacterial communities (accounting for approximately 80.32% of the total) in the root tissue, rhizosphere soil, and bulk soil of healthy C. cathayensis specimens. Further analysis revealed the abundance of genera belonging to Proteobacteria, namely, Acidibacter, Bradyrhizobium, Paraburkholderia, Sphaerotilus, and Steroidobacter, was higher in the root tissues of healthy C. cathayensis specimens than in those of diseased and dead trees. In addition, the abundance of four genera belonging to Actinobacteria, namely, Actinoallomurus, Actinomadura, Actinocrinis, and Gaiella, was significantly higher in the root tissues of healthy C. cathayensis specimens than in those of diseased and dead trees. Altogether, these results suggest that disruption in the balance of these bacterial communities may be associated with the development of root rot in C. cathayensis, and further, our study provides theoretical guidance for the isolation and control of pathogens and diseases related to this important tree species.

• Journal of Ginseng Research
• /
• 제48권2호
• /
• pp.229-235
• /
• 2024

Background: Plant health is directly related to the change in native microbial diversity and changes in soil health have been implicated as one of the main cause of root rot. However, scarce information is present regarding allelopathic relationship of Panax notoginseng root exudates and pathogenic fungi Fusarium oxysporum in a continuous cropping system. Methods: We analyzed P. notoginseng root exudate in the planting soil for three successive years to determine phenolic acid concentration using GC-MS and HPLC followed by effect on the microbial community assembly. Antioxidant enzymes were checked in the roots to confirm possible resistance in P. notoginseng. Results: Total 29 allelochemicals in the planting soil extract was found with highest concentration (10.54 %) of p-hydroxybenzoic acid. The HPLC showing a year-by-year decrease in p-hydroxybenzoic acid content in soil of different planting years, and an increase in population of F. oxysporum. Moreover, community analysis displayed negative correlation with 2.22 mmol. L^-1 of p-hydroxybenzoic acid correspond to an 18.1 % population of F. oxysporum. Furthermore, in vitro plate assay indicates that medium dose of p-hydroxybenzoic acid (2.5-5 mmol. L^-1) can stimulate the growth of F. oxysporum colonies and the production of macroconidia, as well as cell wall-degrading enzymes. We found that 2-3 mmol. L^-1 of p-hydroxybenzoic acid significantly increased the population of F. oxysporum. Conclusion: In conclusion, our study suggested that p-hydroxybenzoic acid have negative effect on the root system and modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease.