Nitrification potential in the rhizosphere of Australian native vegetation

Soil Research ◽  
2017 ◽  
Vol 55 (1) ◽  
pp. 58 ◽  
Author(s):  
Saikat Chowdhury ◽  
Ramya Thangarajan ◽  
Nanthi Bolan ◽  
Julianne O'Reilly-Wapstra ◽  
Anitha Kunhikrishnan ◽  
...  
Keyword(s):  
Plant Growth ◽  
Microbial Activity ◽  
Plant Species ◽  
Native Plants ◽  
Rhizosphere Soil ◽  
Native Vegetation ◽  
Rhizosphere Soils ◽  
Nitrification Potential ◽  
Growth Experiments ◽  
Australian Native Plants

The rhizosphere influences nutrient dynamics in soil mainly by altering microbial activity. The objective of this study was to evaluate the rhizosphere effect on nitrogen transformation in Australian native vegetation in relation to nitrification potential (NP). Microbial activity, NP, and nitrifiers (ammonia-oxidising bacteria, AOB) were compared between rhizosphere and non-rhizosphere soils of several Australian native vegetation under field conditions. These parameters were also measured with increasing distance from the rhizosphere of selected plant species using plant growth experiments. To examine the persistence of nitrification inhibitory activity of rhizosphere soil on non-rhizosphere soil, the soils were mixed at various ratios and examined for NP and AOB populations. The rhizosphere soil from all native vegetation (29 species) had higher microbial activity than non-rhizosphere soil, whereas 13 species showed very low NP in the rhizosphere when compared with non-rhizosphere soil. Nitrification potential and AOB populations obtained in the soil mixture were lower than the predicted values, indicating the persistence of a nitrification inhibitory effect of the rhizosphere soils on non-rhizosphere soils. In plant growth experiments the microbial activity decreased with increasing distance from rhizosphere, whereas the opposite was observed for NP and AOB populations, indicating the selective inhibition of nitrification process in the rhizosphere of the Australian native plants Scaevola albida, Chrysocephalum semipapposum, and Enteropogon acicularis. Some Australian native plants inhibited nitrification in their rhizosphere. We propose future studies on these selected plant species by identifying and characterising the nitrification inhibiting compounds and also the potential of nitrification inhibition in reducing nitrogen losses through nitrate leaching and nitrous oxide emission.

scholarly journals Allelopathy of Knotweeds as Invasive Plants

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Hisashi Kato-Noguchi
Keyword(s):  
Plant Species ◽  
Mycorrhizal Fungi ◽  
Invasive Plant ◽  
Native Plants ◽  
Rhizosphere Soil ◽  
Arbuscular Mycorrhizal ◽  
Plant Residues ◽  
Japanese Knotweed ◽  
Plant Parts ◽  
Germination And Growth

Perennial herbaceous Fallopia is native to East Asia, and was introduced to Europe and North America in the 19th century as an ornamental plant. Fallopia has been spreading quickly and has naturalized in many countries. It is listed in the world’s 100 worst alien species. Fallopia often forms dense monospecies stands through the interruption of the regeneration process of indigenous plant species. Allelopathy of Japanese knotweed (Fallopia japonica), giant knotweed (Fallopia sachalinensis), and Bohemian knotweed (Fallopia x bohemica) has been reported to play an essential role in its invasion. The exudate from their roots and/or rhizomes, and their plant residues inhibited the germination and growth of some other plant species. These knotweeds, which are non-mycorrhizal plants, also suppressed the abundance and species richness of arbuscular mycorrhizal fungi (AMF) in the rhizosphere soil. Such suppression was critical for most territorial plants to form the mutualism with AMF, which enhances the nutrient and water uptake, and the tolerance against pathogens and stress conditions. Several allelochemicals such as flavanols, stilbenes, and quinones were identified in the extracts, residues, and rhizosphere soil of the knotweeds. The accumulated evidence suggests that some of those allelochemicals in knotweeds may be released into the rhizosphere soil through the decomposition process of their plant parts, and the exudation from their rhizomes and roots. Those allelochemicals may inhibit the germination and growth of native plants, and suppress the mycorrhizal colonization of native plants, which provides the knotweeds with a competitive advantage, and interrupts the regeneration processes of native plants. Therefore, allelopathy of knotweeds may contribute to establishing their new habitats in the introduced ranges as invasive plant species. It is the first review article focusing on the allelopathy of knotweeds.

Autotoxicity of aquatic extracts from chrysanthemum and rhizosphere soil on photosynthesis in the same plant species

2009 ◽  
Vol 17 (2) ◽  
pp. 318-322
Author(s):  
Kai ZHOU ◽  
Wei-Ming GUO ◽  
Zhi-Fang WANG ◽  
Feng-Ge HAO
Keyword(s):  
Plant Species ◽  
Rhizosphere Soil

scholarly journals MICROBIAL ACTIVITY AND MYCORRHIZAL POTENTIAL OF FOUR OVERBURDEN TYPES USED IN THE RECLAMATION OF EXTRACTED OIL SANDS

1983 ◽  
Vol 63 (2) ◽  
pp. 363-375 ◽  
Author(s):  
R. M. DANIELSON ◽  
S. VISSER ◽  
D. PARKINSON
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Plant Species ◽  
Oil Sands ◽  
Microbial Respiration ◽  
Bottom Layer ◽  
Jack Pine ◽  
Litter Bags ◽  
Mycorrhizal Development ◽  
Slender Wheatgrass

Slender wheatgrass and jack pine were grown in the greenhouse in cores containing a bottom layer of extracted oil sands with four overburdens individually layered over the sand. The overburdens included a muskeg peat, two shallow mineral overburdens and a deep overburden. Mycorrhizal development, microbial respiration and biomass and the degree of decomposition of slender wheatgrass roots in litter bags were determined in each plant species-overburden combination. Both ecto- and vesicular-arbuscular (VA) mycorrhizal inoculum was present in all four overburdens. The symbionts of slender wheatgrass were the "fine endophyte" and Glomus aggregatum. VA development was very low in peat whereas plants in the shallow overburdens became heavily mycorrhizal. Infection did not spread from the overburden layer to roots in the tailing sand. Jack pine roots in the peat and two shallow overburdens were heavily infected after 4 months. The most common symbiont was an ascomycete known as the E-strain. Microbial respiration was highest in the peat and was not influenced by plant species. Microbial biomass was also highest in the peat and much lower in the mineral overburdens. Only in the peat was the amount of microbial biomass larger with slender wheatgrass than with jack pine. Slender wheatgrass roots decomposed most rapidly in the peat overburden and least rapidly in the deep overburden. Key words: Microbial activity, jack pine, slender wheatgrass, mycorrhizae, reclamation, oil sands

Spaceflight hardware for conducting plant growth experiments in space: The early years 1960–2000

2003 ◽  
Vol 31 (1) ◽  
pp. 183-193 ◽  
Author(s):  
D.M. Porterfield ◽  
G.S. Neichitailo ◽  
A.L. Mashinski ◽  
M.E. Musgrave
Keyword(s):  
Plant Growth ◽  
Early Years ◽  
Growth Experiments

scholarly journals Antimicrobial activity screening of rhizosphere soil bacteria from tomato and genome-based analysis of their antimicrobial biosynthetic potential

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lu Zhou ◽  
Chunxu Song ◽  
Zhibo Li ◽  
Oscar P. Kuipers
Keyword(s):  
Antimicrobial Activity ◽  
Plant Growth ◽  
Disease Control ◽  
Pseudomonas Syringae ◽  
Rhizosphere Soil ◽  
Erwinia Carotovora ◽  
Gene Clusters ◽  
Vast Number ◽  
Tomato Disease

Abstract Background Tomato plant growth is frequently hampered by a high susceptibility to pests and diseases. Traditional chemical control causes a serious impact on both the environment and human health. Therefore, seeking environment-friendly and cost-effective green methods in agricultural production becomes crucial nowadays. Plant Growth Promoting Rhizobacteria (PGPR) can promote plant growth through biological activity. Their use is considered to be a promising sustainable approach for crop growth. Moreover, a vast number of biosynthetic gene clusters (BGCs) for secondary metabolite production are being revealed in PGPR, which helps to find potential anti-microbial activities for tomato disease control. Results We isolated 181 Bacillus-like strains from healthy tomato, rhizosphere soil, and tomato tissues. In vitro antagonistic assays revealed that 34 Bacillus strains have antimicrobial activity against Erwinia carotovora, Pseudomonas syringae; Rhizoctonia solani; Botrytis cinerea; Verticillium dahliae and Phytophthora infestans. The genomes of 10 Bacillus and Paenibacillus strains with good antagonistic activity were sequenced. Via genome mining approaches, we identified 120 BGCs encoding NRPs, PKs-NRPs, PKs, terpenes and bacteriocins, including known compounds such as fengycin, surfactin, bacillibactin, subtilin, etc. In addition, several novel BGCs were identified. We discovered that the NRPs and PKs-NRPs BGCs in Bacillus species are encoding highly conserved known compounds as well as various novel variants. Conclusions This study highlights the great number of varieties of BGCs in Bacillus strains. These findings pave the road for future usage of Bacillus strains as biocontrol agents for tomato disease control and are a resource arsenal for novel antimicrobial discovery.

Overview of Australian Native Plants

2017 ◽  
pp. 1-4
Author(s):  
Amanda Garner ◽  
La Vergne Lehmann
Keyword(s):  
Native Plants ◽  
Australian Native Plants

scholarly journals New Soil, Old Plants, and Ubiquitous Microbes: Evaluating the Potential of Incipient Basaltic Soil to Support Native Plant Growth and Influence Belowground Soil Microbial Community Composition

2018 ◽  
Author(s):  
Aditi Sengupta ◽  
Priyanka Kushwaha ◽  
Antonia Jim ◽  
Peter A. Troch ◽  
Raina Maier
Keyword(s):  
Microbial Community ◽  
Plant Growth ◽  
Community Composition ◽  
Plant Species ◽  
Soil Microbial Community ◽  
Soil Loss ◽  
Microbial Community Composition ◽  
Parent Material ◽  
Native Plant ◽  
Soil Microbial

The plant-microbe-soil nexus is critical in maintaining biogeochemical balance of the biosphere. However, soil loss and land degradation are occurring at alarmingly high rates, with soil loss exceeding soil formation rates. This necessitates evaluating marginal soils for their capacity to support and sustain plant growth. In a greenhouse study, we evaluated the capacity of marginal incipient basaltic parent material to support native plant growth, and the associated variation in soil microbial community dynamics. Three plant species, native to the Southwestern Arizona-Sonora region were tested with three soil treatments including basaltic parent material, parent material amended with 20% compost, and potting soil. The parent material with and without compost supported germination and growth of all the plant species, though germination was lower than the potting soil. A 16S rRNA amplicon sequencing approach showed Proteobacteria to be the most abundant phyla in both parent material and potting soil, followed by Actinobacteria. Microbial community composition had strong correlations with soil characteristics but not plant attributes within a given soil material. Predictive functional potential capacity of the communities revealed chemoheterotrophy as the most abundant metabolism within the parent material, while photoheterotrophy and anoxygenic photoautotrophy were prevalent in the potting soil. These results show that marginal incipient basaltic soil has the ability to support native plant species growth, and non-linear associations may exist between plant-marginal soil-microbial interactions.

scholarly journals Silicon flow from root to shoot in pepper: a comprehensive in silico analysis reveals a potential linkage between gene expression and hormone signaling that stimulates plant growth and metabolism

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10053
Author(s):  
Fernando Carlos Gómez-Merino ◽  
Libia Iris Trejo-Téllez ◽  
Atonaltzin García-Jiménez ◽  
Hugo Fernando Escobar-Sepúlveda ◽  
Sara Monzerrat Ramírez-Olvera
Keyword(s):  
Plant Growth ◽  
Plant Species ◽  
In Silico ◽  
In Silico Analysis ◽  
Regulatory Elements ◽  
Plant Tissues ◽  
Promoter Regions ◽  
Root Cells ◽  
Physiological Processes ◽  
Silico Analysis

Background Silicon (Si) is categorized as a quasi-essential element for plants thanks to the benefits on growth, development and metabolism in a hormetic manner. Si uptake is cooperatively mediated by Lsi1 and Lsi2. Nevertheless, Lsi channels have not yet been identified and characterized in pepper (Capsicum annuum), while genes involved in major physiological processes in pepper are Si-regulated. Furthermore, Si and phytohormones may act together in regulating plant growth, metabolism and tolerance against stress. Our aim was to identify potential synergies between Si and phytohormones stimulating growth and metabolism in pepper, based on in silico data. Methods We established a hydroponic system to test the effect of Si (0, 60, 125 and 250 mg L−1 Si) on the concentrations of this element in different pepper plant tissues. We also performed an in silico analysis of putative Lsi genes from pepper and other species, including tomato (Solanum lycopersicum), potato (Solanum tuberosum) and Arabidopsis thaliana, to look for cis-acting elements responsive to phytohormones in their promoter regions. With the Lsi1 and Lsi2 protein sequences from various plant species, we performed a phylogenetic analysis. Taking into consideration the Lsi genes retrieved from tomato, potato and Arabidopsis, an expression profiling analysis in different plant tissues was carried out. Expression of Si-regulated genes was also analyzed in response to phytohormones and different plant tissues and developmental stages in Arabidopsis. Results Si concentrations in plant tissues exhibited the following gradient: roots > stems > leaves. We were able to identify 16 Lsi1 and three Lsi2 genes in silico in the pepper genome, while putative Lsi homologs were also found in other plant species. They were mainly expressed in root tissues in the genomes analyzed. Both Lsi and Si-regulated genes displayed cis-acting elements responsive to diverse phytohormones. In Arabidopsis, Si-regulated genes were transcriptionally active in most tissues analyzed, though at different expressed levels. From the set of Si-responsive genes, the NOCS2 gene was highly expressed in germinated seeds, whereas RABH1B, and RBCS-1A, were moderately expressed in developed flowers. All genes analyzed showed responsiveness to phytohormones and phytohormone precursors. Conclusion Pepper root cells are capable of absorbing Si, but small amounts of this element are transported to the upper parts of the plant. We could identify putative Si influx (Lsi1) and efflux (Lsi2) channels that potentially participate in the absorption and transport of Si, since they are mainly expressed in roots. Both Lsi and Si-regulated genes exhibit cis-regulatory elements in their promoter regions, which are involved in phytohormone responses, pointing to a potential connection among Si, phytohormones, plant growth, and other vital physiological processes triggered by Si in pepper.

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