A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activi...
Plant associated bacteria are promising alternatives to chemical fertilizers for plant growth and yield improvement in an eco-friendly manner. In this study, rice associated bacteria were isolated and assessed for mineral phosphate solubilization and indole-3-acetic acid (IAA) production activity in vitro. Six promising strains, which were tentatively identified as phylotaxon Pseudochrobactrum sp. (BRRh-1), Burkholderia sp. (BRRh-2), Burkholderia sp. (BRRh-3), Burkholderia sp. (BRRh-4), Pseudomonas aeruginosa (BRRh-5 and BRRh-6) based on their 16S rRNA gene phylogeny, exhibited significant phosphate solubilizing activity in National Botanical Research Institute phosphate growth medium, and BRRh-4 displayed the highest phosphate solubilizing activity, followed by BRRh-5. The pH of the culture broth declined, resulting in increase of growth rate of bacteria at pH 7, which might be due to organic acid secretion by the strains. In presence of L-tryptophan, five isolates synthesized IAA and the maximum IAA was produced by BRRh-2, followed by BRRh-1. Application of two most efficient phosphate solubilizing isolates BRRh-4 and BRRh-5 by root dipping (colonization) of seedling and spraying at the flowering stage significantly enhanced the growth and grain yield of rice variety BRRI dhan-29. Interestingly, application of both strains with 50% of recommended nitrogen, phosphorus and potassium fertilizers produced equivalent or higher grain yield of rice compared to the control grown with full recommended fertilizer doses, which suggests that these strains may have the potential to be used as bioinoculants for sustainable rice production
Entomopathogenic fungi, often acknowledged primarily for their insecticidal properties, fulfill diverse roles within ecosystems. These roles encompass endophytism, antagonism against plant diseases, promotion of the growth of plants, and inhabitation of the rhizosphere, occurring both naturally and upon artificial inoculation, as substantiated by a growing body of contemporary research. Numerous studies have highlighted the beneficial aspects of endophytic colonization. This review aims to systematically organize information concerning the direct (nutrient acquisition and production of phytohormones) and indirect (resistance induction, antibiotic and secondary metabolite production, siderophore production, and mitigation of abiotic and biotic stresses) implications of endophytic colonization. Furthermore, a thorough discussion of these mechanisms is provided. Several challenges, including isolation complexities, classification of novel strains, and the impact of terrestrial location, vegetation type, and anthropogenic reluctance to use fungal entomopathogens, have been recognized as hurdles. However, recent advancements in biotechnology within microbial research hold promising solutions to many of these challenges. Ultimately, the current constraints delineate potential future avenues for leveraging endophytic fungal entomopathogens as dual microbial control agents.
Turf-grasses are economically important horticultural crops, which have been utilised by humans to improve the environment for more than a thousand years. Turf-grasses are widely distributed in landscapes, slopes and sport fields, such as golf courses. Endophytic fungi are a resource of unexplored fungal diversity with potential bioactive compounds. In this study, culture-independent ITS amplicon sequencing and culture-dependent isolation methods were used to reveal fungal community in roots of the turf-grass Zoysia japonica. A total of 317 OTUs were identified from root samples of Z. japonica by analysis of ITS amplicon reads. Fungal community was dominated by Sordariales (32.45%), followed by Chaetothyriales (18.16%), unknown taxa in Sordariomycetes (14.63%) and Pleosporales (12.48%). During isolation, 151 endophytic fungal strains were obtained from roots of Z. japonica and a variety of taxa were found by ITS amplification and sequencing. Moreover, 11 endophytic fungal species were further characterised in this study, based on morphological characterisation and multi-loci phylogenetic analysis, including Niesslia dimorphospora, a newly-recorded species in Korea and 10 novel species (Dactylaria hwasunensissp. nov., Lophiostoma jeollanense sp. nov., Magnaporthiopsis zoysiaesp. nov., Poaceascoma endophyticumsp. nov., P. koreanumsp. nov., P. magnumsp. nov., P. zoysiiradicicolasp. nov., Stagonospora endophytica sp. nov., Setophoma zoysiaesp. nov. and Pseudorhypophila poaesp. nov.). Antifungal activities of these species were tested against the turf-grass brown patch pathogen Rhizoctonia solani AG2-2(IIIB), with S. zoysiae being the best antagonist. In addition, butanol extract from mycelia of S. zoysiae strongly inhibited R. solani AG2-2(IIIB) in vitro and in planta. The results of this study expand the biodiversity of endophytic fungi and revealed potential biological resources for future turf-grass management and bioactive compound exploitation.
Crop production has been substantially reduced by devastating fungal and oomycete pathogens, and these pathogens continue to threaten global food security. Although chemical and cultural controls have been used for crop protection, these involve continuous costs and time and fungicide resistance among plant pathogens has been increasingly reported. The most efficient way to protect crops from plant pathogens is cultivation of disease-resistant cultivars. However, traditional breeding approaches are laborious and time intensive. Recently, the CRISPR/Cas9 system has been utilized to enhance disease resistance among different crops such as rice, cacao, wheat, tomato, and grape. This system allows for precise genome editing of various organisms via RNA-guided DNA endonuclease activity. Beyond genome editing in crops, editing the genomes of fungal and oomycete pathogens can also provide new strategies for plant disease management. This review focuses on the recent studies of plant disease resistance against fungal and oomycete pathogens using the CRISPR/Cas9 system. For long-term plant disease management, the targeting of multiple plant disease resistance mechanisms with CRISPR/Cas9 and insights gained by probing fungal and oomycete genomes with this system will be powerful approaches.
In this study, we aimed to characterize fungal samples from necrotic lesions on collar regions observed in different sweetpotato growing regions during 2015 and 2016 in Korea. Sclerotia appeared on...