scholarly journals Halophytic bacterial endophytome: a potential source of beneficial microbes for a sustainable agriculture

2020 ◽  
Author(s):  
Christos A. Christakis ◽  
Georgia Daskalogiannis ◽  
Anastasia Chatzakis ◽  
Emmanouil A. Markakis ◽  
Angeliki Sagia ◽  
...  
Keyword(s):  
Sustainable Agriculture ◽  
Endophytic Bacteria ◽  
Pathogenic Fungus ◽  
Bacterial Species ◽  
Species Abundance ◽  
Global Strategy ◽  
In Planta ◽  
Promoting Effect ◽  
Cakile Maritima

AbstractHalophytes have evolved several strategies to survive in saline environments; however, additional support from their associated microbiota could help combat adverse conditions. Endophytic communities of halophytes may be different than those in other plants because salinity acts as an environmental filter. At the same time, they may contribute to the host’s adaptation to adverse environmental conditions and can improve host tolerance against various biotic and abiotic stresses, which may be of importance in modern and sustainable agriculture.In this study the culturable endophytic bacteria of three halophytic species Cakile maritima, Matthiola tricuspidata and Crithmum maritimum were isolated and identified. Endophytic bacteria were isolated from roots and leaves of the sampled plants. Significant differences were observed in bacterial species abundance among different plant species and tissue from which the isolates were obtained. In total, 115 strains were identified by analysis of complete 16S rDNA sequences, while the majority of these isolates were derived from the root samples.The strains were evaluated for their ability to: 1) grow in-vitro in high levels of NaCl; 2) inhibit the growth of the economically important plant pathogenic fungus Verticillium dahliae in vitro and in planta, the human pathogenic fungus Aspergillus fumigatus in vitro, as well as, the economically important plant bacterial pathogens Ralstonia solanacearum and Clavibacter michiganensis in vitro; 3) provide salt tolerance in planta; 4) provide growth promoting effect in planta.Additionally, the genomes of twelve selected isolates, exhibiting interesting features, were sequenced and analysed. Three novel bacterial species were identified that belong to the genus Pseudomonas (two strains) and Arthrobacter (one strain).The outcome of our study is the proof-of-concept that the crop wild relatives (CWR) halophytic microbiome could potentially serve as a source of beneficial microorganisms that could be used (as unique species or as artificial communities) as Bio-Inoculants, for the enhancement of plant growth and stress tolerance in crops, including the high-salinity stress.This is very important in the era of ecosystem degradation and climate change, where the maximizing microbial functions in agroecosystems could be a prerequisite for the future of global sustainable agriculture. Globally, there is a strong need for the identification and bio-banking of novel beneficial endophytic microbes with as many desirable characters, for the development of a new environmentally friendly global strategy in food production that will be based in the sustainable agriculture with low chemical inputs and a low environmental impact.

scholarly journals Endophytic Bacterial Isolates From Halophytes Demonstrate Phytopathogen Biocontrol and Plant Growth Promotion Under High Salinity

2021 ◽  
Vol 12 ◽  
Author(s):  
Christos A. Christakis ◽  
Georgia Daskalogiannis ◽  
Anastasia Chatzaki ◽  
Emmanouil A. Markakis ◽  
Glykeria Mermigka ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
High Salinity ◽  
Growth Promotion ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
In Planta ◽  
Promoting Effect ◽  
Cakile Maritima

Halophytic endophytes potentially contribute to the host’s adaptation to adverse environments, improving its tolerance against various biotic and abiotic stresses. Here, we identified the culturable endophytic bacteria of three crop wild relative (CWR) halophytes: Cakile maritima, Matthiola tricuspidata, and Crithmum maritimum. In the present study, the potential of these isolates to improve crop adaptations to various stresses was investigated, using both in vitro and in-planta approaches. Endophytic isolates were identified by their 16S rRNA gene sequence and evaluated for their ability to: grow in vitro in high levels of NaCl; inhibit the growth of the economically important phytopathogens Verticillium dahliae, Ralstonia solanacearum, and Clavibacter michiganensis and the human pathogen Aspergillus fumigatus; provide salt tolerance in-planta; and provide growth promoting effect in-planta. Genomes of selected isolates were sequenced. In total, 115 endophytic isolates were identified. At least 16 isolates demonstrated growth under increased salinity, plant growth promotion and phytopathogen antagonistic activity. Three showed in-planta suppression of Verticillium growth. Furthermore, representatives of three novel species were identified: two Pseudomonas species and one Arthrobacter. This study provides proof-of-concept that the endophytes from CWR halophytes can be used as “bio-inoculants,” for the enhancement of growth and stress tolerance in crops, including the high-salinity stress.

scholarly journals EKSPLORASI DAN UJI VIRULENSI BAKTERI Bacillus sp. ENDOFIT JAGUNG TERHADAP PENYAKIT BUSUK PELEPAH JAGUNG

2020 ◽  
Vol 22 (2) ◽  
pp. 70-78
Author(s):  
Arum Saputri ◽  
Loekas Soesanto ◽  
Abu Umayah ◽  
Agus Sarjito
Keyword(s):  
Plant Height ◽  
Endophytic Bacteria ◽  
Block Design ◽  
Pathogenic Fungi ◽  
In Vitro Test ◽  
Bacillus Sp ◽  
In Planta ◽  
Fresh Weight ◽  
Randomized Block Design

[EXPLORATION AND VIRULENT TEST OF MAIZE ENDOPHYTE Bacillus sp. AGAINST MAIZE SHEATH BLIGHT]. Capability of endophytic bacterial, effectivity, and its effect on R. solani. and on maize seedlings growth were investigated from April 2018 to January 2019. Exploration of endophytes bacteria in maize was taken from Banyumas Regency (Sumbang, Kembaran, Baturraden) and Purbalingga Regency (Padamara, Bojongsari, Pratin). Taking plant samples using Purposive Random Sampling and Diagonal Sampling methods. Completely randomized design was used in in vitro test with 16 treatments repeated twice. Completely randomized block design was used in in planta experiment with 5 treatments repeated 5 times. The treatment consisted of control, fungiside (mankozeb), and 2 isolates of endophytes bacteria performing the best in vitro result. Variables observed included characteristics of endophytic bacteria and pathogenic fungi, inhibition diameter, incubation period, disease intensity, incidence of disease, AUDPC, plant height, leaf number, root length, plant fresh weight, canopy fresh weight, and root fresh weight. Resultshowed that the exploration obtained 15 endophytic Bacillus sp. isolates. The PD A.4 and BK A.1 isolates werw able to inhibit the growth of pathogenic fungi in-vitro by 56.93 and 51.5%, respectively. The soaking treatment using BK A1 was able to reduce disease intensity by 59.377%, and AUDPC value 34.19%. Endophytic bacteria influence plant height, plant fresh weight, canopy fresh weight, and fresh weight of roots respectively as 89.17 cm, 126.06 g, 106.67 g and 19.4 g.

scholarly journals The Fusarium graminearum t-SNARE Sso2 Is Involved in Growth, Defense, and DON Accumulation and Virulence

2020 ◽  
Vol 33 (7) ◽  
pp. 888-901
Author(s):  
Sean P. O’Mara ◽  
Karen Broz ◽  
Marike Boenisch ◽  
Zixuan Zhong ◽  
Yanhong Dong ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Deletion Mutant ◽  
Expression Profiles ◽  
Pathogenic Fungus ◽  
Gene Expression Profiles ◽  
Plant Diseases ◽  
In Planta ◽  
Head Blight ◽  
Double Deletion

The plant-pathogenic fungus Fusarium graminearum, causal agent of Fusarium head blight (FHB) disease on small grain cereals, produces toxic trichothecenes that require facilitated export for full virulence. Two potential modes of mycotoxin transport are membrane-bound transporters, which move toxins across cellular membranes, and N-ethylmaleimide-sensitive factor attachment receptor (SNARE)-mediated vesicular transport, by which toxins may be packaged as cargo in vesicles bound for organelles or the plasma membrane. In this study, we show that deletion of a gene (Sso2) for a subapically localized t-SNARE protein results in growth alteration, increased sensitivity to xenobiotics, altered gene expression profiles, and reduced deoxynivalenol (DON) accumulation in vitro and in planta as well as reduced FHB symptoms on wheat. A double deletion mutant generated by crossing the ∆sso2 deletion mutant with an ATP-binding cassette transporter deletion mutant (∆abc1) resulted in an additive reduction in DON accumulation and almost complete loss of FHB symptoms in planta. These results suggest an important role of Sso2-mediated subapical exocytosis in FHB progression and xenobiotic defense and are the first report of an additive reduction in F. graminearum DON accumulation upon deletion of two distinct modes of cellular export. This research provides useful information which may aid in formulating novel management plans of FHB or other destructive plant diseases.

Variability and interactions between endophytic bacteria and fungi isolated from leaf tissues of citrus rootstocks

2001 ◽  
Vol 47 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Welington L Araújo ◽  
Walter Maccheroni Jr. ◽  
Carlos I Aguilar-Vildoso ◽  
Paulo AV Barroso ◽  
Halha O Saridakis ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Endophytic Bacteria ◽  
Random Amplified Polymorphic Dna ◽  
Bacterial Species ◽  
Pantoea Agglomerans ◽  
Growth Effect ◽  
Bacillus Species ◽  
Guignardia Citricarpa ◽  
Leaf Tissues

Fungi and bacteria were isolated from surface disinfected leaf tissues of several citrus rootstocks. The principal bacterial species isolated were Alcaligenes sp., Bacillus spp. (including B. cereus, B. lentus, B. megaterium, B. pumilus, and B. subtilis), Burkholderia cepacia, Curtobacterium flaccumfaciens, Enterobacter cloacae, Methylobacterium extorquens, and Pantoea agglomerans, with P. agglomerans and B. pumilus being the most frequently isolated species. The most abundant fungal species were Colletotrichum gloeosporioides, Guignardia citricarpa, and Cladosporium sp. Genetic variability between 36 endophytic bacterial isolates was analysed by the random amplified polymorphic DNA (RAPD) technique, which indicated that B. pumilus isolates were more diverse than P. agglomerans isolates, although genetic diversity was not related to the host plants. In vitro interaction studies between G. citricarpa isolates and the most frequently isolated endophytic bacteria showed that metabolites secreted by G. citricarpa have an inhibitory growth effect on some Bacillus species, and a stimulatory growth effect on P. agglomerans.Key words: endophytes, citrus, fungal-bacterial interaction, RAPD, diversity, Pantoea agglomerans, Bacillus pumilus, Guignardia citricarpa.

scholarly journals Priority effects among amphibian microbes lead to varying levels of Bd infection

2021 ◽  
Author(s):  
Elle M Barnes ◽  
JD Lewis
Keyword(s):  
Bacterial Communities ◽  
Batrachochytrium Dendrobatidis ◽  
Pathogenic Fungus ◽  
Bacterial Species ◽  
Priority Effects ◽  
Bacterial Composition ◽  
Composition And Structure ◽  
Risk Of Extinction ◽  
Inhibitory Potential

Priority effects in host-associated microbiomes can influence not only community composition and structure, but also community functions, such as disease resistance. However, evidence for these priority effects remains scarce. Past studies suggest that amphibian protection from chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is related to antifungal bacterial composition on host skin. Priority effects in these bacterial communities may influence susceptibility to Bd, but this possibility has not been tested. Using in vitro microcosms, we demonstrated that priority effects can influence interactions among amphibian-associated microbes. We observed strong priority effects irrespective of high antifungal ability such that the Bd-inhibitory potential of two strongly inhibitory bacterial species did not always produce higher levels of Bd-inhibition. This result suggests that interactions may be more complex than previously thought. Additionally, our results suggest that priority effects between commensal and pathogenic taxa can be either facilitatory or inhibitory, with the strength and direction of this effect dependent on the composition of the community. Thus, changes in assembly may lead to varying levels of Bd infection, influencing how we might augment amphibian-associated microbiomes to conserve taxa currently at risk of extinction.

scholarly journals First record of the endophytic bacteria of Deschampsia antarctica Ė. Desv. from two distant localities of the maritime Antarctic

2021 ◽  
Vol 11 (1) ◽  
pp. 134-153
Author(s):  
Olga Podolich ◽  
Ievgeniia Prekrasna ◽  
Ivan Parnikoza ◽  
Tamara Voznyuk ◽  
Ganna Zubova ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Bacterial Species ◽  
Vascular Plant ◽  
South Shetland Islands ◽  
Deschampsia Antarctica ◽  
Rrna Gene ◽  
King George Island ◽  
Maritime Antarctic ◽  
Organic Input

Endophytic bacteria, recognized for their beneficial effects on plant development and adaptation, can facilitate the survival of Antarctic plants in severe environments. Here we studied endophytes of the vascular plant Deschampsia antarctica Ė. Desv. from two distantly located regions in the maritime Antarctic: King George Island (South Shetland Islands) and Galindez Island (Argentine Islands). Bacterial group-specific PCR indicated presence of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Cytophaga-Flavobacteria and Actinobacteria in root and leaf endosphere of D. antarctica sampled at four distinct sites of both locations. The diversity of endophytic bacteria was significantly higher in the leaves compared to the roots in plants from Galindez Island. Similarly, the diversity of endophytes was higher in the leaves rather than roots of plants from the King George Island. Twelve bacterial species were isolated from roots of D. antarctica of Galindez Island (the Karpaty Ridge and the Meteo Point) and identified by sequencing the 16S rRNA gene. Isolates were dominated by the Pseudomonas genus, followed by the genera Bacillus and Micrococcus. The vast majority of the isolates exhibited cellulase and pectinase activities, however, Bacillus spp. expressed neither of them, suggesting lack of genetic flow of these traits in endophytic bacilli in the maritime Antarctic. Pseudomonas sp. IMBG305 promoted an increase in the leaf number in most of the treated plant genotypes when compared with non-inoculated plants, and a rapid vegetation period of D. antarctica cultured in vitro, albeit the length of leaves in the treated plants was significantly lower, and flavonoid content leveled off in all treated plants. D. antarctica is known to develop diverse ecotypes with regard to ecological conditions, such as organic input, moisture or wind exposition. The D. antarctica phenotype could be extended further through the endophyte colonization, since phenotypic changes were observed in the inoculated D. antarcticaplants grown in vitro in our study. Herewith, endophytes can contribute to plant phenotypic plasticity, potentially beneficial for adaptation of D. antarctica.

scholarly journals Endophytic bacteria isolated from Leptospermum scoparium produce compounds that inhibit Ilyonectria and Neofusicoccum species in vitro

2015 ◽  
Vol 68 ◽  
pp. 445-445
Author(s):  
W.A. Wicaksono ◽  
E.E. Jones ◽  
J. Monk ◽  
H.J. Ridgway
Keyword(s):  
New Zealand ◽  
Essential Oil ◽  
International Research ◽  
Endophytic Bacteria ◽  
Antimicrobial Properties ◽  
Dual Culture ◽  
Antimicrobial Compounds ◽  
In Planta ◽  
Leptospermum Scoparium

Leptospermum scoparium JRForst et GForst var scoparium or m257;nuka is a New Zealand indigenous shrub This shrub is valued for the essential oil and medicinal honey it produces that have antimicrobial properties International research has demonstrated that endophytic bacteria can either directly produce or modify metabolites in planta Therefore bacteria within the m257;nuka endomicrobiome may also produce antimicrobial compounds A total of 192 endophytic bacteria were recovered from surface sterilised leaf stem and root tissue from three different sites These bacteria were assessed in dual culture assays against the grapevine pathogens Ilyonectria spp and Neofusicoccum spp Eleven and three endophytic bacteria showed ability to inhibit I liriodendri and N luteum respectively These endophytic bacteria produced both diffusible and volatile compounds that inhibited the pathogens Isolate W4R11 inhibited the growth of Ilyonectria spp by 4164 after 7 days incubation Isolate W1R33 could inhibit the faster growing Neofusicoccum spp by 2053 after 3 days incubation Microscopy showed that diffusible compound produced by isolate I1R21 caused hyphae and spore abnormality of Ilyonectria spp This study indicated that m257;nuka can potentially provide a new source of microorganisms for use in sustainable agriculture

scholarly journals IN VITRO SCREENING OF SIDEROPHORE-PRODUCERS FROM UPLAND RICE ROOT ENDOPHYTIC BACTERIA FOR ANTAGONISTIC ACTIVITIES AGAINST FUSARIUMOXYSPORUM, ANDXANTHOMONASORYZEA PV. ORYZAE

2020 ◽  
Vol 8 (12) ◽  
pp. 531-537
Author(s):  
Linh T. T. Ta ◽  
◽  
Nga T. P. Mai ◽  
Huong T. M. To ◽  
Chung D. Mai ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Endophytic Bacteria ◽  
Plant Pathogens ◽  
Upland Rice ◽  
World Population ◽  
Moderate Activity ◽  
In Planta ◽  
The World

Rice is a staple crop for a large part of the world population including Vietnam. Although its export is ranged of second place over the world just after Thailand, rice production in Vietnam is challenging by various issues. The most significant is application of agrochemicals, which are not eco-friendly, leading to side effects on the ecosystem and human health. Endophytic bacteria (EB) possess different beneficial traits such as Plant Growth Promoting (PGP) and antagonistic activities against plant pathogens. In this study, a collection of 150 EB strains have been isolated from upland rice roots grown on the mountain-farm in the Tung village, Nam Co commune, Mu Cang Chai district, Yen Bai province, Vietnam. 119/150 isolates showed siderophoreproduction ability including 12 isolates showed the halo orange zone surrounding colonies of 1 – 10 mm in diameter (Dh), considering them as low level of siderophore production, 80 strains exhibited the moderate activity, Dh of 11 – 30 mm and 27 strains showed strong/high activity, Dh more than 30 mm. All 119 endophytic bacterial isolates were screened for antifungal activity against Fusariumoxysporum (Fo), and antibacterial activity against ​Xanthomonasoryzaepv.​oryzae (Xoo). Of them, thirty isolates showed either antifungal or antibacterial or both activities. Indeed, five isolates showed antifungal activity fifteen isolates exhibited the antibacterial activity. Especially, ten isolates named NC88, NC89, NC126, NC129, NC130, NC131, NC134, NC152, NC153, and NC156 showed antimicrobial activity against both tested pathogens. These results are the starting-up for further investigation in planta under conditions of net house and field trial in order to reveal the potential strains for the development of bioinoculants toward to control the diseases caused by Fo andXoo.

scholarly journals Survey of plant growth promoting and antagonistic traits in winter wheat grain endophytic bacteria

2021 ◽  
pp. 66-72
Author(s):  
Alina Pastoshchuk ◽  
Yuliia Yumyna ◽  
Pavlyna Zelena ◽  
Larysa Skivka
Keyword(s):  
Plant Growth ◽  
Winter Wheat ◽  
Endophytic Bacteria ◽  
Wheat Variety ◽  
Wheat Grain ◽  
In Planta ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Plant Growth Promoting Traits

The aim of this work was to isolate endophytic bacteria from wheat grains and to evaluate their plant growth promoting traits (PGPT) as well as an inhibitory effect on P. syringae pv. atrofaciens (McCulloch) growth. Endophytic bacteria were isolated by a culture-dependent protocol from the grains of winter wheat variety of Ukrainian selection Podolyanka with high resistance to syringae. Totally 2.7±0.09 CFU/1 g of dry wheat grain were isolated, ten cultivable bacterial isolates were obtained. Spore-forming bacilli predominated in the wheat grain endophytic community. Gram-negative fermenting and non-fermenting rod-shaped bacteria and Gram-positive cocci were also present. Seven out of ten isolates possessed numerous plant growth promoting traits including phosphate solubilization, oligonitrotrophy, and indolic compound producing. Two isolates possessed antagoniscic activity against syringae in vitro along with plant growth promoting features. According to biochemical profiling and mass-spectrophotometric identification, these two isolates were assigned to Paenibacillus and Brevibacillus genera. These endophytic bacteria can be considered as promising objects for agrobiotechnology. However, more research is needed to confirm their biotechnological potential in planta experiments

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