scholarly journals Mangrove–diazotroph relationships at the root, tree and forest scales: diazotrophic communities create high soil nitrogenase activities in Rhizophora stylosa rhizospheres

2019 ◽  
Author(s):  
Tomomi Inoue ◽  
Ayako Shimono ◽  
Yasuaki Akaji ◽  
Shigeyuki Baba ◽  
Akio Takenaka ◽  
...  
Keyword(s):  
Nitrogenase Activity ◽  
Operational Taxonomic Unit ◽  
Forest Tree ◽  
Bulk Soil ◽  
Mangrove Plant ◽  
Rhizophora Stylosa ◽  
Soil P ◽  
Nitrogen Acquisition ◽  
Mangrove Plants ◽  
High Soil

Abstract Background and Aims The tidal flats on which mangrove plants grow tend to have low soil nitrogen contents because nitrogen-containing litter is repeatedly washed offshore by ebb tides. Under such circumstances, it is unclear how mangrove plants acquire the nitrogen required to support their vigorous growth. In the present work, chemical and biological characteristics of diazotrophy around mangrove plant roots were surveyed under natural conditions to elucidate mangrove–diazotroph relationships. Methods Soil nitrogenase activity of a representative mangrove plant, Rhizophora stylosa, which has a broad geographical distribution, was measured using the acetylene reduction assay at forest, tree and prop root scales. In addition, diazotrophic community composition was compared between rhizosphere and bulk soil based on sequencing of nifH genes. Key Results Soil nitrogenase activity was high near prop roots, and this pattern was enhanced as soil live root content increased. At the forest scale, we observed high soil nitrogenase activity (acetylene-reducing activity) inside the forest (the highest value was 90.9 µmol C2H2 min−1 cm−3, average 46.8 ± 18.2 µmol C2H2 min−1 cm−3). Rates decreased sharply from the forest to the tidal flat (range 1.2–22.2 µmol C2H2 min−1 cm−3, average 7.9 ± 4.5 µmol C2H2 min−1 cm−3). The nifH operational taxonomic unit composition differed significantly among forest and tree rhizospheres and the bulk soil (P < 0.0001). Conclusions Our results suggest that the accumulation of diazotrophs around R. stylosa mangrove trees enhances the supply of biologically fixed nitrogen to the mangrove roots. This supply is especially important when the soil naturally contains little nitrogen. This nitrogen acquisition system may be a key process that explains the high productivity of mangrove ecosystems.

scholarly journals Antimicrobial and antioxidant activity of bacterial endophytes isolated from leaves of the mangrove plant Rhizophora stylosa

2020 ◽  
Vol 41 (4) ◽  
Author(s):  
Ton That Huu Dat ◽  
Phung Thi Thuy Oanh ◽  
Vu Thi Thanh Tam ◽  
Hoang Le Tuan Anh
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Endophytic Bacteria ◽  
Radical Scavenging ◽  
Mangrove Plant ◽  
Rhizophora Stylosa ◽  
Mangrove Plants ◽  
Antioxidant Agents ◽  
Antimicrobial And Antioxidant Activity ◽  
Ethyl Acetate Extracts

Mangroves are the most productive ecosystems and contain highly diverse plants and microbial communities. Mangrove endophytes are proved to be a rich source of bioactive secondary metabolites. The biological molecules produced by endophytes play an important role in protection of mangrove plants against herbivores, insects as well as pathogens. The present study aimed to isolate the endophytic bacteria from the mangrove plant Rhizophora stylosa and screen antimicrobial and antioxidant activity of ethyl acetate extracts from the isolated endophytic bacteria. A total of 64 endophytic bacterial strains from R. stylosa leaves were isolated, of which ethyl acetate extracts of 14 isolated endophytic strains showed antimicrobial activity against at least one of reference microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 25923, Bacillus subtilis ATCC 27212, Staphylococcus aureus ATCC 12222 and Candida albicans ATCC 7754 with MIC values from 32 to 512 µg/ml. Among them, four strains showed activity against one reference microorganism, five strains showed activity against two reference microorganisms, four strains showed activity against three reference microorganisms, and one strain showed activity against four reference microorganisms. Additionally, the ethyl acetate extracts of 12 isolated endophytic bacteria showed ATBS and DPPH radical scavenging activity with scavenging values from 36.27 ± 2.6% to 71.46 ± 6.6% and from 26.22 ± 3.3% to 57.38 ± 5.8%, respectively. The identification of the five most active endophytic bacteria by 16S rRNA sequences revealed that the endophytes belonged to four genera, including Bacillus, Streptomyces, Pseudovibrio and Pseudomonas. The obtained results suggest that the endophytic bacteria from mangrove plants are a promising reservoir of antimicrobial and antioxidant agents.       

scholarly journals \(\textit{In vitro}\) antioxidant, α-amylase and α-glucosidase inhibitory activities of endophytic bacteria from the roots of the mangrove plant \(\textit{Rhizophora stylosa}\) Griffith

2021 ◽  
Vol 43 (3) ◽  
pp. 125-135
Author(s):  
Ton That Huu Dat ◽  
Oanh Phung Thi Thuy
Keyword(s):  
Microbial Communities ◽  
Endophytic Bacteria ◽  
Biological Molecules ◽  
Bacterial Endophytes ◽  
Mangrove Plant ◽  
Rhizophora Stylosa ◽  
Mangrove Plants ◽  
Inhibitory Activities

Mangrove is one of the highly productive ecosystems and contains diverse plants and microbial communities. Bacterial endophytes from mangroves are considered as a prolific source of biological molecules with important functions in the protection of mangrove plants against herbivores, insects as well as pathogens. The present study aimed to isolate endophytic bacteria from the roots of mangrove plant Rhizophora stylosa and to screen antioxidant,

scholarly journals Antimicrobial and antioxidant activity of bacterial endophytes isolated from leaves of the mangrove plant Rhizophora stylosa

2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Ton That Huu Dat ◽  
Phung Thi Thuy Oanh ◽  
Vu Thi Thanh Tam ◽  
Hoang Le Tuan Anh
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Endophytic Bacteria ◽  
Radical Scavenging ◽  
Mangrove Plant ◽  
Rhizophora Stylosa ◽  
Mangrove Plants ◽  
Antioxidant Agents ◽  
Antimicrobial And Antioxidant Activity ◽  
Ethyl Acetate Extracts

Mangroves are the most productive ecosystems and contain highly diverse plants and microbial communities. Mangrove endophytes are proved to be a rich source of bioactive secondary metabolites. The biological molecules produced by endophytes play an important role in protection of mangrove plants against herbivores, insects as well as pathogens. The present study aimed to isolate the endophytic bacteria from the mangrove plant Rhizophora stylosa and screen antimicrobial and antioxidant activity of ethyl acetate extracts from the isolated endophytic bacteria. A total of 64 endophytic bacterial strains from R. stylosa leaves were isolated, of which ethyl acetate extracts of 14 isolated endophytic strains showed antimicrobial activity against at least one of reference microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 25923, Bacillus subtilis ATCC 27212, Staphylococcus aureus ATCC 12222 and Candida albicans ATCC 7754 with MIC values from 32 to 512 µg/ml. Among them, four strains showed activity against one reference microorganism, five strains showed activity against two reference microorganisms, four strains showed activity against three reference microorganisms, and one strain showed activity against four reference microorganisms. Additionally, the ethyl acetate extracts of 12 isolated endophytic bacteria showed ATBS and DPPH radical scavenging activity with scavenging values from 36.27 ± 2.6% to 71.46 ± 6.6% and from 26.22 ± 3.3% to 57.38 ± 5.8%, respectively. The identification of the five most active endophytic bacteria by 16S rRNA sequences revealed that the endophytes belonged to four genera, including Bacillus, Streptomyces, Pseudovibrio and Pseudomonas. The obtained results suggest that the endophytic bacteria from mangrove plants are a promising reservoir of antimicrobial and antioxidant agents.       

Tracking the route of atmospheric nitrogen to diazotrophs colonizing buried mangrove roots

2019 ◽  
Vol 39 (11) ◽  
pp. 1896-1906
Author(s):  
Tomomi Inoue ◽  
Ayato Kohzu ◽  
Ayako Shimono
Keyword(s):  
Nitrogenase Activity ◽  
Lateral Roots ◽  
Atmospheric Nitrogen ◽  
Rhizophora Stylosa ◽  
15N Labelling ◽  
High Productivity ◽  
Mangrove Ecosystems ◽  
Aerial Roots ◽  
Exposed Part ◽  
Mangrove Roots

Abstract Nitrogen-fixing activity has been observed in the rhizosphere of mangrove ecosystems, suggesting a close mangrove–diazotroph relationship. In regularly flooded soil, however, the pathway by which atmospheric nitrogen reaches the diazotrophs in the rhizosphere is unknown. This study provides evidence that mangrove aerial roots serve as pathways that supply nitrogen gas to the diazotrophs colonizing buried roots. A plastic chamber was attached on the exposed part of a Rhizophora stylosa Griff prop root, and 15N2 tracer gas was injected into it. The entire root, including the below-ground part, was collected for analysis of 15N labelling and nitrogenase activity. We detected 15N labelling in buried root materials 2 h after gas injection. Compared with the δ15N contents in root material from an untreated tree, the increment was &gt;10‰ in lateral roots. The nitrogenase activity measured on the other R. stylosa roots was highest in lateral roots, matching well with the results of 15N labelling. Our results indicate that atmospheric nitrogen is taken into aerial mangrove roots through lenticels, diffuses into the buried root system and is fixed by diazotrophs. The unusual appearance of mangrove aerial roots, which has intrigued researchers for many years, could be a key to the high productivity of mangrove ecosystems.

Diversity of Mangrove Plant for Support Ecotourism Activities in Nature Conservation Forum Putri Menjangan, Pejarakan Buleleng-Bali

2018 ◽  
Vol 9 (5) ◽  
pp. 987
Author(s):  
I Ketut GINANTRA ◽  
Ida Bagus Made SUASKARA ◽  
Martin JONI
Keyword(s):  
Nature Conservation ◽  
Plant Species ◽  
Diversity Index ◽  
Leaf Shape ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Mangrove Plant ◽  
Mangrove Plants ◽  
Wiener Diversity Index ◽  
Mangrove Zonation

This study aims to identify the species of mangrove constituents and determine the zonation of the growing community of mangrove plants from the seaward to the landward zone, of the Nature Conservation Forum (NCF) Putri Menjangan coastal Pejarakan village Buleleng from July to October 2017. Identification of mangrove plant species based on the following characteristics: habitus, root type, fruit shape, inflorescence, leaf shape and leaf arangement. Zoning of mangrove grown is determined from vegetation analysis conducted in 3 zones (front zone, middle zone and back zone) with quadrat method, the area of each square is 20 m x 20 m. Parameters specified in each kwadrat are the density, dominance and frequency of presence of each species. Zoning of mangrove community is determined based on the important value of mangrove plant species. The diversity of the mangrove community is calculated by the Shanon-Wiener Diversity Index. The results of the study identified 13 species of true mangrove plants (mangrove) and 14 mangrove mangrove associates. The dominant species are Sonneratia alba (important value / iv is 98.19), Lumnitzera racemosa (iv. is 40.75), Rhizophora apiculata (iv.is 35.53), Rhizophora mucronata (iv. 33.02), Ceriops decandra (iv.23.61) and Avicennia marina (iv. 22.22). The diversity index of mangrove species (H) is 2.07, then it is considered good. The pattern of growing mangrove plants in coastal Pejarakan Buleleng, in general follow the natural pattern of mangrove zonation. Typical characteristics and patterns of growing mangrove zonation become interesting attractions and reference for mangrove area managers in ecotourism development and efforts to conserve mangrove forests.

scholarly journals Effect of AmtB homologues on the post-translational regulation of nitrogenase activity in response to ammonium and energy signals in Rhodospirillum rubrum

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2075-2089 ◽  
Author(s):  
Yaoping Zhang ◽  
David M. Wolfe ◽  
Edward L. Pohlmann ◽  
Mary C. Conrad ◽  
Gary P. Roberts
Keyword(s):  
Translational Regulation ◽  
Rhodospirillum Rubrum ◽  
Nitrogenase Activity ◽  
Regulatory Protein ◽  
Regulatory System ◽  
Poor Response ◽  
Photosynthetic Bacterium ◽  
Nitrogen Acquisition ◽  
Consistent Model ◽  
Energy Deprivation

The AmtB protein transports uncharged NH3 into the cell, but it also interacts with the nitrogen regulatory protein PII, which in turn regulates a variety of proteins involved in nitrogen fixation and utilization. Three PII homologues, GlnB, GlnK and GlnJ, have been identified in the photosynthetic bacterium Rhodospirillum rubrum, and they have roles in at least four overlapping and distinct functions, one of which is the post-translational regulation of nitrogenase activity. In R. rubrum, nitrogenase activity is tightly regulated in response to addition or energy depletion (shift to darkness), and this regulation is catalysed by the post-translational regulatory system encoded by draTG. Two amtB homologues, amtB 1 and amtB 2, have been identified in R. rubrum, and they are linked with glnJ and glnK, respectively. Mutants lacking AmtB1 are defective in their response to both addition and darkness, while mutants lacking AmtB2 show little effect on the regulation of nitrogenase activity. These responses to darkness and appear to involve different signal transduction pathways, and the poor response to darkness does not seem to be an indirect result of perturbation of internal pools of nitrogen. It is also shown that AmtB1 is necessary to sequester detectable amounts GlnJ to the cell membrane. These results suggest that some element of the AmtB1-PII regulatory system senses energy deprivation and a consistent model for the integration of nitrogen, carbon and energy signals by PII is proposed. Other results demonstrate a degree of specificity in interaction of AmtB1 with the different PII homologues in R. rubrum. Such interaction specificity might be important in explaining the way in which PII proteins regulate processes involved in nitrogen acquisition and utilization.

ANALISIS VEGETASI MANGROVE DAN PEMANFAATANNYA OLEH MASYARAKAT KAMPUNG ISENEBUAI DISTRIK RUMBERPON KABUPATEN TELUK WONDAMA

2008 ◽  
Vol 7 (1) ◽  
Author(s):  
Yan F.A. Auri
Keyword(s):  
Plant Species ◽  
Construction Material ◽  
Musical Instrument ◽  
Bruguiera Gymnorrhiza ◽  
Mangrove Plant ◽  
Rhizophora Stylosa ◽  
Interview Technique ◽  
Mangrove Tree ◽  
Xylocarpus Granatum ◽  
Ceriops Tagal

<p><em>The objective of this research was to know the structure, composition, potency of mangrove tree and also exploitation of mangrove observation type in Isenebuai Village District Rumberpon Teluk Wondama. Vegetation observation was conducted using line and plot method and the interview technique flourish structure. The result of analyse vegetasi study show that 11 mangrove plant species from 5 families were found.The 11 species are Aegiceras corniculatum, Bruguiera sylindrica, Bruguiera gymnorrhiza, Rhizophora stylosa ,Rhizophora mucronata, Ceriops tagal, Heritiera littoralis, Heritiera globosa, Lumnitzera litorea, Xylocarpus granatum and  Xylocarpus moluccensis. The result also show that local people used 7 mangrove plant species from 4 families for 7 categories of use that are food-stuff, construction material, medicine, energy sources, boat supply, musical instrument and equipments of artistry and furniture.</em></p>

scholarly journals Single or dual inoculation of arbuscular mycorrhizal fungi and rhizobia regulates plant growth and nitrogen acquisition in white clover

2020 ◽  
Vol 66 (No. 6) ◽  
pp. 287-294
Author(s):  
Miao-Miao Xie ◽  
Ying-Ning Zou ◽  
Qiang-Sheng Wu ◽  
Ze-Zhi Zhang ◽  
Kamil Kuča
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
White Clover ◽  
Mycorrhizal Fungi ◽  
Nitrogenase Activity ◽  
Arbuscular Mycorrhizal ◽  
Total Soluble Protein ◽  
Nitrogen Acquisition ◽  
Dual Inoculation ◽  
N Acquisition

The present work aimed to analyse whether and how single or dual inoculation with arbuscular mycorrhizal fungi (Funneliformis mosseae, Paraglomus occultum, and Rhizophagus intraradices) and rhizobia (Rhizobium trifolii) improved plant growth and stimulated nitrogen (N) acquisition of white clover. AMF inoculation significantly (P &lt; 0.05) increased root nodule number by 117‒173%, and additional Rh considerably stimulated mycorrhizal growth. Single AMF or Rh treatment dramatically increased shoot by 36‒281% and root biomass by 16‒36% than non-inoculated control, and dual inoculation of Rh and P. occultum or R. intraradices further magnified the positive effect. Leaf and root N content, root total soluble protein content, root nitrogenase activity, and amino acid (e.g., alanine, arginine, asparagine, aspartate, phenylalanine, proline, and tryptophan) concentrations were significantly increased by single or dual inoculation, while dual inoculation of AMF and Rh had significantly superior roles than single corresponding AMF or Rh inoculation. These results suggested that AMF and Rh represented synergetic effects on accelerating N acquisition of white clover to some extent, while the combination of P. occultum and Rh was the best.  

Influence of Elevated CO2 and Phosphorus Nutrition on the Growth and Yield of a Short-Duration Rice (Oryza sativa L. Cv. Jarrah)

1994 ◽  
Vol 21 (3) ◽  
pp. 281 ◽  
Author(s):  
S Seneweera ◽  
P Milham ◽  
J Conroy
Keyword(s):  
Oryza Sativa ◽  
Elevated Co2 ◽  
Short Duration ◽  
Oryza Sativa L ◽  
Co2 Enrichment ◽  
Grain Number ◽  
High Co2 ◽  
Soil P ◽  
High Soil ◽  
Co2 Levels

The growth and development of a short-duration rice cultivar (Oryza sativa L. cv. Jarrah), grown in flooded soil with a range of phosphorus (P) levels and exposed to atmospheric CO2 concentrations of either 350 or 700 μL L-1 was followed for 146 days after planting (DAP). Development (estimated by rate of tiller production and time to flowering) was faster with higher soil P levels and CO2 enrichment, the effect being more pronounced with CO2 enrichment. During the early vegetative phase (up to 35 DAP), when rates of tiller production were low, shoot growth and rates of leaf expansion were faster at elevated CO2 concentrations and high soil P levels. Rates of tiller production were greater with these treatments during the 35-56 DAP period, when tillering was at a maximum. Shoot elongation was reduced at elevated CO2 levels and at high soil P levels during this period. By 146 DAP leaf weight was greater at high P levels, but CO2 enrichment accelerated tiller production to such an extent that final leaf weight was lower at high CO2, probably because there were fewer, and smaller, leaves on each tiller. Despite this, grain yield was increased by up to 58% by CO2 enrichment, with increases occurring even at low soil P levels. This was due mainly to an increase in grain number per panicle, although panicle number also increased. Higher soil P levels also increased grain number and yield. The P concentration in the foliage was unaffected by the CO2 treatments and the concentration required to produce maximum yield was 0.18% (dry wt basis) at both CO2 levels. Greater starch accumulation in the stems of high-CO2-grown plants may have accounted for the higher number of grains in each panicle.

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