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Effects of Bacillus amyloliquefaciens and different phosphorus sources on Maize plants as revealed by NMR and GC-MS based metabolomics

Authors:
Giovanni Vinci at University of Naples Federico II
Giovanni Vinci
Vincenza Cozzolino at University of Naples Federico II
Vincenza Cozzolino
Pierluigi Mazzei at University of Salerno
Pierluigi Mazzei
Hiarhi Monda at Huma Inc.
Hiarhi Monda
  • Huma Inc.
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Abstract and Figures

AimsPlant growth-promoting bacteria of the genus Bacillus are known to solubilize phosphates and enhance plant growth in many plant species. We explored the effects of the inoculation with a commercial isolate Bacillus amyloliquefaciens on the growth and metabolic processes of maize plants in pot soils treated with triple superphosphate, rock phosphate, and either cow- or horse-manure composts, as P-fertilizers. Methods The metabolic profiles of maize leaves in the different treatments were determined by both Gas Chromatography–Mass Spectrometry and Nuclear Magnetic Resonance spectroscopy. Principle Components Analysis (PCA) based on data matrix from both techniques revealed a relationship between treatments and specific plant metabolites. ResultsInoculated plants showed larger P and N contents and a more differentiated metabolome when treated with the two composts than with inorganic fertilizers. B. amyloliquefaciens in combination with composts significantly increased glucose, fructose, alanine and GABA metabolites in maize leaves, thus suggesting an improved photosynthetic activity due to enhanced P and N uptake. Both composts sustained plant growth and the phosphate solubilizing activity of B. amyloliquefaciens, while differences in P and N contents in plant leaves were attributed to the different content in compost of lignin residues and alkyl moieties, and consequent impact on microbial growth. Conclusions The combination of B. amyloliquefaciens inoculation with composted organic P-fertilizers rich in available metabolic carbon appears as an efficient alternative to mineral fertilizers to enhance nutrients uptake and foster growth mechanisms in maize plants.
Plant shoots dry weight (a), leaf phosphorus concentration and content (b,c), leaf nitrogen concentration and content (d, e), chlorophyll content, in control (B0) and inoculated maize plants (B1) treated with different P-based fertilizers (P0-P4), . Error bars indicate standard deviation (n = 5) and different letters indicate significant differences by the Tukey’s test (p ≤ 0.05 at a significance of 0.05). Plant growth, P and N uptake data were reported in Thonar et al. (2017) with SEM values, ± SD are provided
Plant shoots dry weight (a), leaf phosphorus concentration and content (b,c), leaf nitrogen concentration and content (d, e), chlorophyll content, in control (B0) and inoculated maize plants (B1) treated with different P-based fertilizers (P0-P4), . Error bars indicate standard deviation (n = 5) and different letters indicate significant differences by the Tukey’s test (p ≤ 0.05 at a significance of 0.05). Plant growth, P and N uptake data were reported in Thonar et al. (2017) with SEM values, ± SD are provided
… 
a PCA score-plot based on GC-MS and ¹H NMR data of leaves harvested from maize plants treated with different P-based fertilizers (P0-P4) without microbial inoculum (B0). Names and direction of most significant PCA loading vectors involved in the differentiation of treatments are reported along the score-plot borders. b Heatmap visualization of most discriminant variables grouped as follows: amino acids, carbohydrates and alcohols, organic acids, N-containing compounds
a PCA score-plot based on GC-MS and ¹H NMR data of leaves harvested from maize plants treated with different P-based fertilizers (P0-P4) without microbial inoculum (B0). Names and direction of most significant PCA loading vectors involved in the differentiation of treatments are reported along the score-plot borders. b Heatmap visualization of most discriminant variables grouped as follows: amino acids, carbohydrates and alcohols, organic acids, N-containing compounds
… 
a PCA score-plot based on GC-MS and ¹H NMR data of leaves harvested from maize plants inoculated with Bacillus amyloliquefaciens (B1) and treated with different P-based fertilizers (P0-P4). Names and direction of most significant PCA loading vectors involved in the differentiation of treatments are reported along the score-plot borders. b Heatmap visualization of most discriminant variables grouped as follows: amino acids, carbohydrates and alcohols, organic acids, N-containing compounds
a PCA score-plot based on GC-MS and ¹H NMR data of leaves harvested from maize plants inoculated with Bacillus amyloliquefaciens (B1) and treated with different P-based fertilizers (P0-P4). Names and direction of most significant PCA loading vectors involved in the differentiation of treatments are reported along the score-plot borders. b Heatmap visualization of most discriminant variables grouped as follows: amino acids, carbohydrates and alcohols, organic acids, N-containing compounds
… 
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REGULAR ARTICLE
Effects of Bacillus amyloliquefaciens and different phosphorus
sources on Maize plants as revealed by NMR and GC-MS
based metabolomics
Giovanni Vinci &Vincenza Cozzolino &
Pierluigi Mazzei &Hiarhi Monda &Davide Savy &
Marios Drosos &Alessandro Piccolo
Received: 6 March 2018 /Accepted: 28 May 2018 /Published online: 11 June 2018
#Springer International Publishing AG, part of Springer Nature 2018
Abstract
Aims Plant growth-promoting bacteria of the genus
Bacillus are known to solubilize phosphates and en-
hance plant growth in many plant species. We explored
the effects of the inoculation with a commercial isolate
Bacillus amyloliquefaciens on the growth and metabolic
processes of maize plants in pot soils treated with triple
superphosphate, rock phosphate, and either cow- or
horse-manure composts, as P-fertilizers.
Methods The metabolic profiles of maize leaves in the
different treatments were determined by both Gas
Chromatography–Mass Spectrometry and Nuclear
Magnetic Resonance spectroscopy. Principle
Components Analysis (PCA) based on data matrix from
both techniques revealed a relationship between treat-
ments and specific plant metabolites.
Results Inoculated plants showed larger P and N con-
tents and a more differentiated metabolome when treat-
ed with the two composts than with inorganic fertilizers.
B. amyloliquefaciens in combination with composts
significantly increased glucose, fructose, alanine and
GABA metabolites in maize leaves, thus suggesting an
improved photosynthetic activity due to enhanced P and
N uptake. Bothcomposts sustained plant growth and the
phosphate solubilizing activity of B. amyloliquefaciens,
while differences in P and N contents in plant leaves
were attributed to the different content in compost of
lignin residues and alkyl moieties, and consequent im-
pact on microbial growth.
Conclusions The combination of B. amyloliquefaciens
inoculation with composted organic P-fertilizers rich in
available metabolic carbon appears as an efficient alter-
native to mineral fertilizers to enhance nutrients uptake
and foster growth mechanisms in maize plants.
Keywords Metabolomics .Phosphate-solubilizing-
bacteria .Compost .Rock phosphate .Triple
Superphosphate .GC-MS .
1
H-NMR .
Thermochemolysis
Introduction
Phosphorus (P) is an essential macronutrient for plants,
although the content and bioavailability of P in most
soils are limiting factors for plants growth and develop-
ment. Highly reactive phosphate (Pi) based fertilizers,
such as triple super phosphate (TSP) and di-ammonium
phosphate (DAP), are commonly added to agricultural
soils to maintain crop productivity. Nevertheless, only a
small percentage of phosphate fertilizers is uptaken by
plants, while most of added phosphate is rapidly
Plant Soil (2018) 429:437–450
https://doi.org/10.1007/s11104-018-3701-y
Responsible Editor: Tim S. George.
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s11104-018-3701-y)contains
supplementary material, which is available to authorized users.
G. Vinci (*):V. C o z z o l i n o (*):P. M a z z e i :H. Monda :
D. Savy :M. Drosos :A. Piccolo
Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica
Nucleare per l’Ambiente, l’Agroalimentare ed i Nuovi Materiali
(CERMANU), Università di Napoli Federico II, Via Università,
100, 80055 Portici, NA, Italy
e-mail: giovanni.vinci@unina.it
e-mail: vincenza.cozzolino@unina.it
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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Arbuscular mycorrhizal fungi (AMF) transfer plant photosynthate underground which can stimulate soil microbial growth. In this study, we examined whether there was a potential link between carbon (C) release from an AMF and phosphorus (P) availability via a phosphate‐solubilizing bacterium ( PSB ). We investigated the outcome of the interaction between the AMF and the PSB by conducting a microcosm and two Petri plate experiments. An in vitro culture experiment was also conducted to determine the direct impact of AMF hyphal exudates on growth of the PSB . The AMF released substantial C to the environment, triggering PSB growth and activity. In return, the PSB enhanced mineralization of organic P, increasing P availability for the AMF . When soil available P was low, the PSB competed with the AMF for P, and its activity was not stimulated by the fungus. When additional P was added to increase soil available P, the PSB enhanced AMF hyphal growth, and PSB activity was also stimulated by the fungus. Our results suggest that an AMF and a free‐living PSB interacted to the benefit of each other by providing the C or P that the other microorganism required, but these interactions depended upon background P availability.
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1H NMR and GC-MS based metabolomics reveal nano-Cu altered cucumber (Cucumis sativus) fruit nutritional supply
Article
  • Feb 2016
It is imperative to study the interaction of nanoparticles residuals with crop plants in agricultural soils, due to the increased application of nanotechnology in agriculture. So far, a few studies have focused on the impact of nanoparticles on fruit quality and nutritional supply. In this work, a thorough and comprehensive analysis of metabolite changes of cucumber fruits for plants under nano-Cu stress was possible through the use of both 1H NMR and GC-MS. The results of supervised partial least-squares discriminant analysis from both platforms showed that cucumber fruit extracts samples were clearly grouped based on the nano-Cu level in soil. This indicates that the fruit metabolite profile was influenced by exposure to nano-Cu. GC-MS data showed concentrations of some sugars, organic acids, amino acids, and fatty acids were increased or decreased by nano-Cu. Several metabolites, such as methylnicotinamide (MNA), trigonelline, imidazole, quinolinate were only detected and quantified by 1H NMR. Our results showed that combining the two platforms provided a comprehensive understanding about the metabolites (nutrient supply) changes in cucumber fruits impacted by exposure to nano-Cu.
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Leaf Senescence
Article
  • Jan 1982
  • Annu Rev Plant Physiol
For some time it has been conventional to regard leaf senescence as a species of catastrophe in which the activities of the mature, carbon-exporting leaf lose both their integrity and coordination in an essentially unregulated manner. This view assumes parallels with gerontological changes occurring in humans and other animals. However, it is becoming increasingly apparent that leaf senescence is least understood when considered in these terms and that degenerative sequences in plants and animals, whilst having underlying similarities, also have fundamental differences.
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A Modified Single Solution Method for the Dermination of Phosphate in Natural Waters
Article
  • Jan 1962
  • ANAL CHIM ACTA
A single solution reagent is described for the determination of phosphorus in sea water. It consists of an acidified solution of ammonium molybdate containing ascorbic acid and a small amount of antimony. This reagent reacts rapidly with phosphate ion yielding a blue-purple compound which contains antimony and phosphorus in a 1:1 atomic ratio. The complex is very stable and obeys Beer's law up to a phosphate concentration of at least 2 μg/ml.The sensitivity of the procedure is comparable with that of the stannous chloride method. The salt error is less than 1 %.
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