Application of the Scholander pressure bomb to studies on endophytic bacteria of plants

1997 ◽  
Vol 43 (5) ◽  
pp. 411-416 ◽  
Author(s):  
J. Hallmann ◽  
J. W. Kloepper ◽  
R. Rodríguez-Kábana
Keyword(s):  
Endophytic Bacteria ◽  
Vascular Plant ◽  
Taxonomic Diversity ◽  
Common Species ◽  
Root Surface ◽  
Plant Colonization ◽  
Root Cortex ◽  
Bacillus Spp ◽  
Pressure Bomb ◽  
Bomb Method

The Scholander pressure bomb system, which expresses vascular plant sap, was compared with the trituration method, in which roots are surface disinfested and triturated, for recovery of endophytic bacteria. The two methods were compared for recovery of indigenous and introduced endophytes from roots of several plant genera. The pressure bomb method was acceptable for routine recovery of endophytes from cotton (Gossypium hirsutum), soybean (Glycine max), and bean (Phaseolus vulgaris), but owing to tissue collapse under pressure, the method did not work reliably for cucumber (Cucumis sativa) or tomato (Lycopersicon esculentum) seedlings. High bacterial densities on the root surface, experimentally obtained by dipping cotton roots into a suspension of Enterobacter asburiae JM22 immediately prior to processing, did not affect the population densities of recovered indigenous endophytic bacteria by the pressure bomb technique but resulted in increased bacterial densities for the trituration method. Internal populations of JM22 following application as a seed treatment were statistically equivalent with the trituration and pressure bomb techniques. Analysis of taxonomic diversity of a group of indigenous endophytes recovered with the trituration and pressure bomb techniques indicated some differences between the two groups. The total number of bacterial genera and species recovered was greater using the pressure bomb method. Gram-positive species, such as Bacillus spp., were more frequently isolated with the trituration method than with the pressure bomb method. Agrobacterium radiobacter and less common species were more often isolated using the pressure bomb technique. Pseudomonas spp. and Phyllobacterium spp. were recovered with equal frequencies using both techniques. These results suggest that the two techniques sample two different internal habitats available for colonization by endophytic bacteria, i.e., the trituration method recovering mainly endophytes residing in the root cortex and the pressure bomb method detecting vascular colonists. A combination of both methods is recommended for understanding the full pattern of internal plant colonization by endophytic bacteria.Key words: endophytic bacteria, Scholander pressure bomb, isolation method, cotton.

Carbon dioxide and methane fluxes from arctic mudboils

2010 ◽  
Vol 90 (3) ◽  
pp. 441-449 ◽  
Author(s):  
K S Wilson ◽  
E R Humphreys
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Vascular Plant ◽  
Organic Matter Content ◽  
Net Ecosystem Exchange ◽  
The Arctic ◽  
Plant Colonization ◽  
Patterned Ground ◽  
Organic C ◽  
C Balance

Climate change is expected to alter the Arctic’s carbon (C) balance and changes in these C-rich ecosystems may contribute to a positive feedback on global climate change. Low-center mudboils, a form of patterned ground in the Arctic, are distinct landforms in which the exchange of greenhouse gases between the atmosphere and soil has not been fully characterized, but which may have an important influence on the overall C balance of tundra ecosystems. Chamber systems were used to sample net ecosystem exchange of CO2 (NEE) and CO2 and CH4 effluxes along a 35-m transect intersecting two mudboils in a wet sedge fen in Canada’s Southern Arctic (lat. 64°52′N, long. 111°34′W) during the summer months in 2008. Mudboil features gave rise to dramatic variations in vegetation, soil temperature and thaw depth, and soil organic matter content along this transect. Variations in NEE were driven by variations in the amount of vascular vegetation, while CO2 and CH4 effluxes were remarkably similar among the two mudboil (CO2 effluxes: 1.1 ± 0.9 and 1.4 ± 0.7 µmol m-2 s-1; CH4 effluxes: 83.1 ± 189.4 and 23.1 ± 9.4 nmol m-2 s-1, ± 1 standard deviation) and the sedge fen (CO2 effluxes: 1.6 ± 0.7 mol m-2 s-1 ; CH4 effluxes: 28.0 ± 62.0 nmol m-2 s-1) sampling areas. Vegetation appeared to play an important role in limiting temporal variations in CH4 effluxes through plant mediated transport in both mudboil and sedge fen sampling areas. One of the mudboils had negligible vascular plant colonization presumably due to more active frost heave processes. The relatively high CO2 and CH4 efflux in this mudboil area was speculated to be a result of growth and decomposition of cryptogamic organisms, inflow of dissolved organic C, and warmer soil temperatures. Key words: Patterned ground, nonsorted circle, tundra, net ecosystem exchange, methane, carbon dioxide

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (19) ◽  
pp. 5521-5537 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that, with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species-poor grassland will develop and persist, as on the old neighbouring islands.

scholarly journals Exopolysaccharide Production Is Required for Biofilm Formation and Plant Colonization by the Nitrogen-Fixing Endophyte Gluconacetobacter diazotrophicus

2011 ◽  
Vol 24 (12) ◽  
pp. 1448-1458 ◽  
Author(s):  
Carlos H. S. G. Meneses ◽  
Luc F. M. Rouws ◽  
Jean L. Simões-Araújo ◽  
Marcia S. Vidal ◽  
José I. Baldani
Keyword(s):  
Biofilm Formation ◽  
Bacterial Species ◽  
Carbon Sources ◽  
Normal Growth ◽  
Root Surface ◽  
Plant Colonization ◽  
Gluconacetobacter Diazotrophicus ◽  
Nitrogen Fixing ◽  
Wild Type ◽  
Endophytic Colonization

The genome of the endophytic diazotrophic bacterial species Gluconacetobacter diazotrophicus PAL5 (PAL5) revealed the presence of a gum gene cluster. In this study, the gumD gene homologue, which is predicted to be responsible for the first step in exopolysaccharide (EPS) production, was insertionally inactivated and the resultant mutant (MGD) was functionally studied. The mutant MGD presented normal growth and nitrogen (N2) fixation levels but did not produce EPS when grown on different carbon sources. MGD presented altered colony morphology on soft agar plates (0.3% agar) and was defective in biofilm formation on glass wool. Most interestingly, MGD was defective in rice root surface attachment and in root surface and endophytic colonization. Genetic complementation reverted all mutant phenotypes. Also, the addition of EPS purified from culture supernatants of the wild-type strain PAL5 to the mutant MGD was effective in partially restoring wild-type biofilm formation and plant colonization. These data provide strong evidence that the PAL5 gumD gene is involved in EPS biosynthesis and that EPS biosynthesis is required for biofilm formation and plant colonization. To our knowledge, this is the first report of a role of EPS in the endophytic colonization of graminaceous plants by a nitrogen-fixing bacterium.

A comparison of systematic errors between the Richards and Hammel methods of measuring tissue – water relations parameters

1978 ◽  
Vol 56 (17) ◽  
pp. 2153-2161 ◽  
Author(s):  
M. T. Tyree ◽  
M. E. MacGregor ◽  
A. Petrov ◽  
M. I. Upenieks
Keyword(s):  
Cell Wall ◽  
Osmotic Pressure ◽  
Water Relations ◽  
Turgor Pressure ◽  
Systematic Errors ◽  
Tissue Water ◽  
Cell Wall Elasticity ◽  
Pressure Bomb ◽  
Bomb Method

The pressure bomb is being used to a much greater extent to measure some tissue – water relations parameters such as osmotic pressure, turgor pressure, and cell wall elasticity. Recently, Richards has developed a faster pressure-bomb method of obtaining these and other parameters than the method used by Hammel and modified by us. In this paper, we compare the two methods and conclude that Richards’ method should not be used when accuracy is deemed important. The Richards method usually overestimates osmotic pressure by 0.2 MPa (= 2 bars) and sometimes by 0.8 MPa (= 8 bars).

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

2019 ◽  
Author(s):  
O. Podolich ◽  
I. Parnikoza ◽  
T. Voznyuk ◽  
G. Zubova ◽  
I. Zaets ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Vascular Plant ◽  
First Record ◽  
Deschampsia Antarctica ◽  
Rrna Gene ◽  
King George Island ◽  
Maritime Antarctica ◽  
Pcr Screening ◽  
Specific Pcr ◽  
The 16S Rrna Gene

AbstractThe vascular plant Deschampsia antarctica samples were collected for endophytic bacteria study from two regions in the maritime Antarctic 400 km distant from one another: Point Thomas oasis (King George Island) and Argentine Islands (Galindez Island). The endophytes were isolated from roots and leaves of D. antarctica, cultivated and identified by using a partial sequencing of the 16S rRNA gene served as a phylomarker. Endophyte isolates from two sites of Galindez Island were represented mainly by Pseudomonas species and by Gammaproteobacteria, Firmicutes and Actinobacteria. The vast majority of the isolates had specific for endophytes cellulase and pectinase activities, however, Bacillus spp. did not express both activities. A group-specific PCR screening at the four sites of Galindez Island and two sites of King George Island, indicated Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Cytophaga-Flavobacteria and Actinobacteria. Notably, the number of endophytic bacteria taxa was significantly larger in leaves than in roots of plants.

scholarly journals MALDI-TOF MS Detection of Endophytic Bacteria Associated with Great Nettle (Urtica dioica L.), Grown in Algeria

2018 ◽  
Vol 67 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Souheyla Toubal ◽  
Ouahiba Bouchenak ◽  
Djillali Elhaddad ◽  
Karima Yahiaoui ◽  
Sarah Boumaza ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Vascular System ◽  
Common Species ◽  
Urtica Dioica ◽  
Biochemical Tests ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Identification Of Bacteria ◽  
The Common ◽  
Tof Ms

Any plant with a vascular system has a specific endophytic microflora. The identification of bacteria is essential in plant pathology. Although identification methods are effective, they are costly and time consuming. The purpose of this work is to isolate and to identify the different bacteria from the internal tissues of Urtica dioica L. and to study their diversity. This last is based on the different parts of the plant (stems, leaves and roots) and the harvest regions (Dellys and Tlamcen). The identification of bacteria is done by biochemical tests and confirmed by MALDI-TOF MS. Seven genus and eleven species were isolated from the Great Nettle. They belong to the genera Bacillus, Escherichia, Pantoea, Enterobacter, Staphylococcus, Enterococcus and Paenibacillus. The majority of these bacteria were isolated from Tlemcen which makes this region the richest in endophytic bacteria compared to that harvested from Dellys. The results show also that the leaves are the most diversified in endophytic bacteria. Bacillus pumilus-ME is the common species of the three parts of the plant harvested in both regions. From this work, it emerges that the Great Nettle can be settled by various endophytic bacteria which are differently distributed within the same plant harvested in different regions.

scholarly journals Non-native species in the vascular flora of highlands and mountains of Iceland

2015 ◽  
Author(s):  
Pawel Wasowicz
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Hot Springs ◽  
Vascular Plant ◽  
Temporal Trends ◽  
Plant Colonization ◽  
Native Plant ◽  
Alien Plant ◽  
Alien Flora ◽  
Central Highland

Highlands and mountains of Iceland (defined here as areas located above 400 m a.s.l) are considered to be the largest remaining wilderness areas in Europe. The present study provides first comprehensive and up-to-date data on non-native plant species from this area. The study was aimed to provide a checklist of alien plant species recorded from highland and mountain areas of Iceland, assess their naturalisation status, define spatial patterns and hotspots of their distribution and analyse temporal trends in the data. The presence of 18 non-native vascular plant species was evidenced including 13 casuals and 5 naturalised taxa (1 invasive). The results showed that the central highland is most vulnerable to alien plant colonisation, while mountain and highland areas in other parts of the country are much less impacted by non-native plant taxa. Clear hotspots of occurrence of alien flora can be defined and their geographic location corresponds to places of touristic interest such as hot springs, geothermal areas, mountain huts and shelters as well as main roads and tracks. Temporal trends characterizing non-native plant colonization show clearly that the process is still in its initial phase. The research suggests that human-mediated dispersal is the major force contributing to increased invasion risk within the investigated area.

scholarly journals Non-native species in the vascular flora of highlands and mountains of Iceland

2015 ◽  
Author(s):  
Pawel Wasowicz
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Hot Spots ◽  
Vascular Plant ◽  
Temporal Trends ◽  
Second Step ◽  
Plant Colonization ◽  
Native Plant ◽  
Alien Plant ◽  
Vascular Plant Species

The highlands and mountains of Iceland, defined here as areas located above 400 m above sea level (m.a.s.l.) are one of the largest remaining wilderness areas in Europe. The present study was aimed to provide the first comprehensive and up-to-date data on non-native plant species from this region. The study was aimed to answer the following questions: (1) How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2) Do temporal trends in alien species immigration to Iceland and highland areas differ? (3) Do human disturbed and undisturbed areas within Icelandic highlands differ in terms of alien species occurrence? (4) Is spread within the highland areas a second step in alien plant colonization? and (5) Can we point out hot-spots in the distribution of non native taxa within highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive). Results showed that temporal trends in alien species immigration to Iceland and to highland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. It was evidenced that non-native plants tend to occur close to man-made infrastructure and buildings including huts, shelters, road network etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were be identified using Getis-Ord Gi* statistic and linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Icelandic highlands and mountain areas.

scholarly journals Medicinal plants in segetal communities of the Kałuszyńska Upland

2010 ◽  
Vol 61 (1) ◽  
pp. 105-114
Author(s):  
Teresa Skrajna
Keyword(s):  
Medicinal Plants ◽  
Chenopodium Album ◽  
Vascular Plant ◽  
Ground Cover ◽  
Common Species ◽  
Life Forms ◽  
Convolvulus Arvensis ◽  
Stellaria Media ◽  
Anthemis Arvensis ◽  
Segetal Communities

Medicinal plants in segetal communities of the Kałuszyńska Upland The herbal flora of agrocenoses of the Kałuszyńska Upland includes 137 vascular plant species. Apophytes (91species-66,4%) prevail over anthropophytes (46 species-33,6 %). Meadow (32 species), waterside (20 species) and forest apophytes (17 species) were the most numerous. Short-lived plants (71 species) prevail over perennials (66 species) in the analysed flora. Therophytes (65 species) and hemicryptophytes (48 species) were the dominant life forms. Very rare, rare and quite rare species were the most frequent in the flora of the Kałuszyńska Upland. They build up over 63% of the total number of species. The share of common and very common species was about 8%. Some of them, e.g, Equisetum arvense, Chenopodium album, Viola arvensis, Anthemis arvensis, Centaurea cyanus, Cirsium arvense, Elymus repens Convolvulus arvensis, Capsella bursapastoris and Stellaria media were noted with a high ground cover. The occurrence of species rare in the region and in Poland among recorded medicinal plants, e.g., Camelina microcarpa sp. sylvestris, Hypericum humifusum, Consolida regalis, Asperugo procumbens and Herniaria glabra is especially noteworthy.

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