• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.1-9
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• 2014

So far it has been generally considered that proteomic approaches are very useful for studying plant-microbes interaction. In this review, recent studies based on papers published from 2010 to 2013 have investigated proteomics analysis in various interaction during plant-fungal pathogen infection by means of gel-based proteomics coupled with mass spectrometry (MS)-based analysis. In rice, three papers focused on rice-Magnaporthe oryzae interaction were mainly reviewed in this study. Interestingly, another study showed proteomic changes in rice inoculated with Puccinia triticina, which is not only an fungal pathogen in wheat and but also results to the disease resistance with non-host defense manner in rice. Additionally, proteomics analysis has been widely subjected to understand defense mechanism during other crops (wheat, tomato, strawberry and mint) and their fungal pathogen interaction. Crops inoculated are analyzed to identify differentially regulated proteins at various tissues such as leaf and apoplast using 2-DE analysis coupled with various MS approaches such as MALDI-TOF MS, nESI-LC-MS/MS and MudPIT, respectively. Taken together, this review article shows that proteomics is applicable to various organisms to understand plant-fungal pathogen interaction and will contribute to provide important information for crop disease diagnosis and crop protection.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.1-11
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• 2015

Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources.

• The Plant Pathology Journal
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• v.20 no.1
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• pp.13-17
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• 2004

An interaction between Legumes and Rhizobia establishes a symbiotic new organ, the nodule that supports atmospheric nitrogen fIxation. The specific communications between the microbes and legume plants are necessary for both nodulation and nitrogen fixation. Through genetic and biochemical analyses several genes playing pivotal roles in nodulation had been identified to be a receptor kinase like CALVATAl involved signal transduction for development. This emphasizes peptides as signals to be transmitted for a short or long distance transport for nodulation. In addition, a quorum sensing in rhizobia has become a focus as counterpart signal. In an attempt to reveal proteins factors and signaling molecules acting on nodulation, proteome analyses of nodule and the proteins in apoplast upon communication between Legumes and Rhizobia were performed.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.83-93
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• 2006

In heavily industrialized areas, soil sites are contaminated with high concentrations of heavy metals. These pollutants are highly accumulated to the human body through the food web and cause serious diseases. To remove heavy metals from the soil, a potential strategy is the environmental friendly and cost effective phytoremediation. For the enhancement of remediation efficiency, the symbiotic interaction between the plant and plant growth-promoting rhizobacteria (PGPR) has been attended. In this review, the interaction of the plant and PGPR in the heavy metal-contaminated soil has been reviewed. The physicochemical and biological characteristics of the rhlzosphere can influence directly or indirectly on the biomass, activity and population structure of the rhizobacteria. The root exudates are offered to the soil microbes as useful carbon sources and growth factors, so the growth and metabolism of rhizobacteria can be promoted. PGPR have many roles to lower the level of growth-inhibiting stress ethylene within the plant, and also to provide iron and phosphorus from the soil to plant, and to produce phytohormone such as indole acetic acid. The plant with PGPR can grow better in the heavy metal contaminated soil. Therefore higher efficiency of the phytoremediation will be expected by the application of the PGPR.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1349-1360
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• 2015

The rhizospheric zone abutting plant roots usually clutches a wealth of microbes. In the recent past, enormous genetic resources have been excavated with potential applications in host plant interaction and ancillary aspects. Two Pseudomonas strains were isolated and identified through 16S rRNA and rpoD sequence analyses as P. fluorescens QAU67 and P. putida QAU90. Initial biochemical characterization and their root-colonizing traits indicated their potential role in plant growth promotion. Such aerobic systems, involved in gluconic acid production and phosphate solubilization, essentially require the pyrroloquinoline quinine (PQQ)-dependent glucose dehydrogenase (GDH) in the genome. The PCR screening and amplification of GDH and PQQ and subsequent induction of mutagenesis characterized their possible role as antioxidants as well as in growth promotion, as probed in vitro in lettuce and in vivo in rice, bean, and tomato plants. The results showed significant differences (p ≤ 0.05) in parameters of plant height, fresh weight, and dry weight, etc., deciphering a clear and in fact complementary role of GDH and PQQ in plant growth promotion. Our study not only provides direct evidence of the in vivo role of GDH and PQQ in host plants but also reveals their functional inadequacy in the event of mutation at either of these loci.

• The Plant Pathology Journal
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• v.36 no.3
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• pp.255-266
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• 2020

Plant immune responses can be triggered by chemicals, microbes, pathogens, insects, or abiotic stresses. In particular, induced systemic resistance (ISR) refers to the activation of the immune system due to a plant's interaction with beneficial microorganisms. The phenolic compound, 2,4-diacetylphloroglucinol (DAPG), which is produced by beneficial Pseudomonas spp., acts as an ISR elicitor, yet DAPG's mechanism in ISR remains unclear. In this study, transgenic Arabidopsis thaliana plants overexpressing the DAPG hydrolase gene (phlG) were generated to investigate the functioning of DAPG in ISR. DAPG was applied onto 3-week-old A. thaliana Col-0 and these primed plants showed resistance to the pathogens Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000. However, in the phlG transgenic A. thaliana, the ISR was not triggered against these pathogens. The DAPG-mediated ISR phenotype was impaired in transgenic A. thaliana plants overexpressing phlG, thus showing similar disease severity when compared to untreated control plants. Furthermore, the DAPG-treated A. thaliana Col-0 showed an increase in their gene expression levels of PDF1.2 and WRKY70 but this failed to occur in the phlG transgenic lines. Collectively, these experimental results indicate that jasmonic acid/ethylene signal-based defense system is effectively disabled in phlG transgenic A. thaliana lines.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.185-195
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• 2006

Phytoremediation is an economical and environmentally friendly bioremediation technique using plants which can increase the microbial population in soil. Unlike other pollutants such as heavy metals, poly-chlorinated biphenyl, trichloroethylene, perchloroethylene and so on, petroleum hydrocarbons are relatively easily degradable by soil microbes. For successful phytoremediation of soil contaminated with petroleum hydrocarbons, it is important to select plants with high removal efficiency through microbial degradation. In this study, we clarified the roles of plants and rhizobacteria and identified their species effective on phytore-mediation by reviewing the papers previously reported. Plants and rhizobacteria can degrade and remove the petroleum hydrocarbons directly and indirectly by stimulating each other's degradation activity. The preferred plant species are alfalfa, ryegrass, tall fescue, poplar, corn, etc. The microorganisms with a potential to degrade hydrocarbons mostly belong to Pseudomonas spp., Bacillus spp., and Alcaligenes spp. It has been reported that the elimination efficiency of hydrocarbons by soil microorganisms can be improved when plants were simultaneously applied. For more efficient restoration, it's necessary to understand the plant-rhizobacteria interaction and to select the suitable plant and microorganism species.