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Genes Nov 2023Maize white spot (MWS), caused by the bacterium , is a serious disease that significantly impacts maize production and productivity. In recent years, outbreaks of white... (Review)
Review
Maize white spot (MWS), caused by the bacterium , is a serious disease that significantly impacts maize production and productivity. In recent years, outbreaks of white spot disease have resulted in substantial maize yield losses in southwest China. Researchers from various countries worldwide have conducted extensive research on this pathogen, including its isolation and identification, the localization of resistance genes, transmission pathways, as well as potential control measures. However, the information related to this disease remains fragmented, and standardized preventive and control strategies have not yet been established. In light of this, this review aims to comprehensively summarize the research findings on MWS, providing valuable insights into understanding its occurrence, prevention, and control measures in the southwestern and southern regions of China while also mitigating the detrimental impact and losses caused by MWS on maize production in China and across the world.
Topics: Zea mays; China
PubMed: 38003004
DOI: 10.3390/genes14112061 -
Microbiology Resource Announcements Jul 2021We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms....
We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms. ASB05 was isolated from fresh cherries purchased in Albany, CA, in 2016.
PubMed: 34323608
DOI: 10.1128/MRA.00501-21 -
Microorganisms May 2021Volatile organic compounds (VOCs) play an essential role in microbe-microbe and plant-microbe interactions. We investigated the interaction between two plant...
Volatile organic compounds (VOCs) play an essential role in microbe-microbe and plant-microbe interactions. We investigated the interaction between two plant growth-promoting rhizobacteria, and their interaction with tomato plants. VOCs produced by MVC 21 modulates the release of siderophores, the solubilisation of phosphate and potassium by () MVC 17. Moreover, VOCs produced by MVC 21 increased lateral root density (LRD), root and shoot dry weight of tomato seedlings. Among the VOCs released by MVC 21, only dimethyl disulfide (DMDS) showed effects similar to MVC 21 VOCs. Because of the effects on plants and bacterial cells, we investigated how MVC 21 VOCs might influence bacteria-plant interaction. Noteworthy, VOCs produced by MVC 21 boosted the ability of MVC 17 to increase LRD and root dry weight of tomato seedlings. These results could be explained by the positive effect of DMDS and MVC 21 VOCs on acid 3-indoleacetic production in MVC 17. Overall, our results clearly indicated that MVC 21 is able to establish a beneficial interaction with MVC 17 and tomato plants through the emission of DMDS.
PubMed: 34072820
DOI: 10.3390/microorganisms9061186 -
Virus Research May 2023In this study, the genome of the lytic broad-host-range phage Key infecting Erwinia amylovora, Erwinia horticola, and Pantoea agglomerans strains was characterized. Key...
In this study, the genome of the lytic broad-host-range phage Key infecting Erwinia amylovora, Erwinia horticola, and Pantoea agglomerans strains was characterized. Key phage has a 115,651 bp long double-stranded DNA genome with the G + C ratio of 39.03%, encoding 182 proteins and 27 tRNA genes. The majority (69%) of predicted coding sequences (CDSs) encode proteins with unknown functions. The protein products of 57 annotated genes were found to have probable functions in nucleotide metabolism, DNA replication, recombination, repair, and packaging, virion morphogenesis, phage-host interaction and lysis. Furthermore, the product of gene 141 shared amino acid sequence similarity and conserved domain architecture with the exopolysaccharide (EPS) degrading proteins of Erwinia and Pantoea infecting phages as well as bacterial EPS biosynthesis proteins. Due to the genome synteny and similarity to the proteins of T5-related phages, phage Key, together with its closest relative, Pantoea phage AAS21, was suggested to represent a novel genus within the Demerecviridae family, for which we tentatively propose the name "Keyvirus".
Topics: Bacteriophages; Erwinia amylovora; Host Specificity; Virion; Genome, Viral
PubMed: 36907559
DOI: 10.1016/j.virusres.2023.199088 -
PloS One 2019The Enterobacterial genus Pantoea contains both free-living and host-associating species, with considerable debate as to whether documented reports of human infections...
The Enterobacterial genus Pantoea contains both free-living and host-associating species, with considerable debate as to whether documented reports of human infections by members of this species group are accurate. MALDI-TOF-based identification methods are commonly used in clinical laboratories as a rapid means of identification, but its reliability for identification of Pantoea species is unclear. In this study, we carried out cpn60-based molecular typing of 54 clinical isolates that had been identified as Pantoea using MALDI-TOF and other clinical typing methods. We found that 24% had been misidentified, and were actually strains of Citrobacter, Enterobacter, Kosakonia, Klebsiella, Pseudocitrobacter, members of the newly described Erwinia gerundensis, and even several unclassified members of the Enterobacteriaceae. The 40 clinical strains that were confirmed to be Pantoea were identified as Pantoea agglomerans, Pantoea allii, Pantoea dispersa, Pantoea eucalypti, and Pantoea septica as well as the proposed species group, Pantoea latae. Some species groups considered largely environmental or plant-associated, such as P. allii and P. eucalypti were also among clinical specimens. Our results indicate that MALDI-TOF-based identification methods may misidentify strains of the Enterobacteriaceae as Pantoea.
Topics: Bacterial Typing Techniques; Diagnostic Errors; Enterobacteriaceae Infections; Humans; Pantoea; Phylogeny; Plants; Reproducibility of Results; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 31682625
DOI: 10.1371/journal.pone.0224731 -
Plant Disease Sep 2023Schisandra chinensis (Turcz.) Baill is a perennial liana, which is widely cultivated and used in China. In August 2022, Schisandra chinensis leaves with small light...
Schisandra chinensis (Turcz.) Baill is a perennial liana, which is widely cultivated and used in China. In August 2022, Schisandra chinensis leaves with small light brown spots were found on plants growing in Fusong (127°28'E, 42°33'N) of China. There was 15% disease incidence and 50% disease severity of Schisandra chinensis in 2-ha fields of S. chinensis. As the disease progressed, the spots become darker and form round or irregular concentric circles. Leaves with brown spot symptoms were collected from the field. Leaf pieces (5 mm × 5 mm) were excised from lesion margins, surface disinfected with 75% ethanol for 1 min, followed by 1.5% sodium hypochlorite for 3 min, and incubated on Luria Bertani (LB) solid medium at 28°C for 24 hours. Eight cultures were isolated, and representative single colony (XWWZH) was selected from the pure cultures according to colony characteristics for observation The purified colonies were round, yellow, and slimy, cells were straight rod-shaped (0.40 to 0.52 × 1.12 to 1.69 µm) were observed. The isolate was Gram negative. It was positive for methyl red reaction, lysine decarboxylase reaction, gelatin hydrolysis reactionand sucrose utilization. It was negative for indole reaction and produced H2S. The bacterium was preliminarily identified as Pantoea agglomerans based on morphological and biochemical tests (Baird et al. 2007). The 16S rDNA and a portion of rpoB of strain XWWZH were amplified and sequenced. The sequences were submitted to GenBank. (Accession OP763753 and OQ813505, respectively). Phylogenetic trees were constructed based on the 16S rDNA and rpoB gene sequences. The sequences of strain XWWZH clustered with strains P. agglomerans deposited in GenBank. The pathogenicity was verified with non-wounded S. chinensis seedlings by punching holes with sterile needles and injecting a solution of 1 × 108 CFU/ml solution. Sterile ddH2O was injected in the control experiment. The inoculated seedlings were incubated in a greenhouse at 25°C with a relative humidity of 65 to 70%. Five to eight days after inoculation, inoculated leaves, exhibited symptoms which were morphologically identical to those of the originally infected leaves whereas control plants remained asymptomatic. The pathogenicity assays were repeated twice with the same results. The re-isolated pathogen had the same morphology and DNA sequences as the original isolate obtained from the field samples, completing Koch's postulates. Strains of P. agglomerans have been reported to severely infect many plants (Ren et al.2008; Lee et al. 2010; Yang et al. 2011; Guo et al. 2019; Gao et al, 2022), but to the best of our knowledge, this is the first report of a strain of P. agglomerans causing leaf blight on Schisandra chinensis in China. The identification of leaf blight caused by P. agglomerans will enable farmers to prevent and manage it ahead of time to reduce losses.
PubMed: 37729653
DOI: 10.1094/PDIS-07-23-1258-PDN -
Frontiers in Microbiology 2021Plant microbiomes play an important role in agricultural productivity, but there is still much to learn about their provenance, diversity, and organization. In order to...
Plant microbiomes play an important role in agricultural productivity, but there is still much to learn about their provenance, diversity, and organization. In order to study the role of vertical transmission in establishing the bacterial and fungal populations of juvenile plants, we used high-throughput sequencing to survey the microbiomes of seeds, spermospheres, rhizospheres, roots, and shoots of the monocot crops maize (B73), rice (Nipponbare), switchgrass (Alamo), , wheat, sugarcane, barley, and sorghum; the dicot crops tomato (Heinz 1706), coffee (Geisha), common bean (G19833), cassava, soybean, pea, and sunflower; and the model plants (Columbia-0) and (Bd21). Unsterilized seeds were planted in either sterile sand or farm soil inside hermetically sealed jars, and after as much as 60 days of growth, DNA was extracted to allow for amplicon sequence-based profiling of the bacterial and fungal populations that developed. Seeds of most plants were dominated by Proteobacteria and Ascomycetes, with all containing operational taxonomic units (OTUs) belonging to and . All spermospheres also contained DNA belonging to , , and . Despite having only seeds as a source of inoculum, all plants grown on sterile sand in sealed jars nevertheless developed rhizospheres, endospheres, and phyllospheres dominated by shared Proteobacteria and diverse fungi. Compared to sterile sand-grown seedlings, growth on soil added new microbial diversity to the plant, especially to rhizospheres; however, all 63 seed-transmitted bacterial OTUs were still present, and the most abundant bacteria (, , , , and ) were the same dominant seed-transmitted microbes observed in sterile sand-grown plants. While most plant mycobiome diversity was observed to come from soil, judging by read abundance, the dominant fungi ( and ) were also vertically transmitted. Seed-transmitted fungi and bacteria appear to make up the majority of juvenile crop plant microbial populations by abundance, and based on occupancy, there seems to be a pan-angiosperm seed-transmitted core bacterial microbiome. Further study of these seed-transmitted microbes will be important to understand their role in plant growth and health, as well as their fate during the plant life cycle and may lead to innovations for agricultural inoculant development.
PubMed: 34745040
DOI: 10.3389/fmicb.2021.737616 -
International Journal of Molecular... Sep 2022Due to the observed climate warming, water deficiency in soil is currently one of the most important stressors limiting the size and quality of plant crops. Drought...
Due to the observed climate warming, water deficiency in soil is currently one of the most important stressors limiting the size and quality of plant crops. Drought stress causes a number of morphological, physiological, and biochemical changes in plants, limiting their growth, development, and yield. Innovative methods of inducing resistance and protecting plants against stressors include the inoculation of crops with beneficial microorganisms isolated from the rhizosphere of the plant species to which they are to be applied. The aim of the present study was to evaluate 12 different strains of rhizosphere bacteria of the genera , , , and by using them to inoculate strawberry plants and assessing their impact on mitigating the negative effects of drought stress. Bacterial populations were assessed by estimates of their size based on bacterial counts in the growth substrate and with bioassays for plant growth-promoting traits. The physiological condition of strawberry plants was determined based on the parameters of chlorophyll fluorescence. The usefulness of the test methods used to assess the influence of plant inoculation with rhizosphere bacteria on the response of plants growing under water deficit was also evaluated. A two-factor experiment was performed in a complete randomization design. The first experimental factor was the inoculation of plant roots with rhizosphere bacteria. The second experimental factor was the different moisture content of the growth substrate. The water potential was maintained at -10 to -15 kPa under control conditions, and at -40 to -45 kPa under the conditions of water deficit in the substrate. The tests on strawberry plants showed that the highest sensitivity to water deficiency, and thus the greatest usefulness for characterizing water stress, was demonstrated by the following indices of chlorophyll "a" fluorescence: F, F, F/F, PI, and Area. Based on the assessment of the condition of the photosynthetic apparatus and the analysis of chlorophyll "a" fluorescence indices, including hierarchical cluster analysis, the following strains of rhizosphere bacteria were found to have favorable effects on strawberry plants under water deficit: the sp. strains DLGB2 and DKB26 and the sp. strains DKB63, DKB70, DKB68, DKB64, and DKB65. In the tests, these strains of sp. exhibited a common trait-the ability to produce siderophores, while those of sp. were notable for phosphate mobilization and ACCD activity.
Topics: Bacillus; Bacteria; Chlorophyll; Crops, Agricultural; Fragaria; Phosphates; Plant Roots; Rhizosphere; Siderophores; Soil; Soil Microbiology
PubMed: 36142361
DOI: 10.3390/ijms231810449 -
Environmental Microbiome Jun 2024Seed endophytes have a significant impact on plant health and fitness. They can be inherited and passed on to the next plant generation. However, the impact of breeding...
BACKGROUND
Seed endophytes have a significant impact on plant health and fitness. They can be inherited and passed on to the next plant generation. However, the impact of breeding on their composition in seeds is less understood. Here, we studied the indigenous seed microbiome of a recently domesticated perennial grain crop (Intermediate wheatgrass, Thinopyrum intermedium L.) that promises great potential for harnessing microorganisms to enhance crop performance by a multiphasic approach, including amplicon and strain libraries, as well as molecular and physiological assays.
RESULTS
Intermediate wheatgrass seeds harvested from four field sites in Europe over three consecutive years were dominated by Proteobacteria (88%), followed by Firmicutes (10%). Pantoea was the most abundant genus and Pantoea agglomerans was identified as the only core taxon present in all samples. While bacterial diversity and species richness were similar across all accessions, the relative abundance varied especially in terms of low abundant and rare taxa. Seeds from four different breeding cycles (TLI C3, C5, C704, C801) showed significant differences in bacterial community composition and abundance. We found a decrease in the relative abundance of the functional genes nirK and nifH as well as a drop in bacterial diversity and richness. This was associated with a loss of amplicon sequence variants (ASVs) in Actinobacteria, Alphaproteobacteria, and Bacilli, which could be partially compensated in offspring seeds, which have been cultivated at a new site. Interestingly, only a subset assigned to potentially beneficial bacteria, e.g. Pantoea, Kosakonia, and Pseudomonas, was transmitted to the next plant generation or shared with offspring seeds.
CONCLUSION
Overall, this study advances our understanding of the assembly and transmission of endophytic seed microorganisms in perennial intermediate wheatgrass and highlights the importance of considering the plant microbiome in future breeding programs.
PubMed: 38886863
DOI: 10.1186/s40793-024-00584-3 -
Microbiology Resource Announcements Dec 2023Here, we describe draft genome sequences for two bacterial isolates from the genus . ATCC 35400 was originally isolated from honeydew melon and was obtained from the...
Here, we describe draft genome sequences for two bacterial isolates from the genus . ATCC 35400 was originally isolated from honeydew melon and was obtained from the American Type Culture Collection. subspecies ICMP 10132 was originally isolated from sugarcane and classified as , but average nucleotide identity and discriminatory PCR support species reclassification.
PubMed: 37982615
DOI: 10.1128/MRA.00471-23