Repositorio
Institucional

Barra, Patricio J.

Viscardi, Sharon#Jorquera, Milko A.#Duran, Paola A.#Valentine, Alexander J.#de la Luz Mora, Maria

Understanding the Strategies to Overcome Phosphorus-Deficiency and Aluminum-Toxicity by Ryegrass Endophytic and Rhizosphere Phosphobacteria

FRONTIERS MEDIA SA

FRONTIERS IN MICROBIOLOGY

en

Phosphobacteria, secreting organic acids and phosphatases, usually favor plant performance in acidic soils by increasing phosphorus (P) availability and aluminum (Al) complexing. However, it is not well-known how P-deficiency and Al-toxicity affect the phosphobacteria physiology. Since P and Al problems often co-occur in acidic soils, we have therefore proposed the evaluation of the single and combined effects of P-deficiency and Al-toxicity on growth, organic acids secretion, malate dehydrogenase (mdh) gene expression, and phosphatase activity of five Al-tolerant phosphobacteria previously isolated from ryegrass. These phosphobacteria were identified as Klebsiella sp. RC3, Stenotrophomona sp. RC5, Klebsiella sp. RCJ4, Serratia sp. RCJ6, and Enterobacter sp. RJAL6. The strains were cultivated in mineral media modified to obtain (i) high P in absence of Al-toxicity, (ii) high P in presence of Al-toxicity, (iii) low P in absence of Al-toxicity, and (iv) low P in presence of Al-toxicity. High and low P were obtained by adding KH2PO4 at final concentration of 1.4 and 0.05mM, respectively. To avoid Al precipitation, AlCl3 x 6H(2)O was previously complexed to citric acid (sole carbon source) in concentrations of 10mM. The secreted organic acids were identified and quantified by HPLC, relative mdh gene expression was determined by qRT-PCR and phosphatase activity was colorimetrically determined using p-nitrophenyl phosphate as substrate. Our results revealed that although a higher secretion of all organic acids was achieved under P-deficiency, the patterns of organic acids secretion were variable and dependent on treatment and strain. The organic acid secretion is exacerbated when Al was added into media, particularly in the form of malic and citric acid. The mdh gene expression was significantly up-regulated by the strains RC3, RC5, and RCJ6 under P-deficiency and Al-toxicity. In general, Al-tolerant phosphobacteria under P deficiency increased both acid and alkaline phosphatase activity with respect to the control, which was deepened when Al was present. The knowledge of this bacterial behavior in vitro is important to understand and predict the behavior of phosphobacteria in vivo. This knowledge is essential to generate smart and efficient biofertilizers, based in Al-tolerant phosphobacteria which could be expansively used in acidic soils.

Artículo original

This study was financed by the Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) of Chilean government through FONDECYT Postdoctoral Project No. 3170629, FONDECYT Regular Projects No. 1160302, 1141247, and 1181050. This study was also funding by Proyecto REDES ETAPA INICIAL, Convocatoria 2017, REDI170334.

Este estudio fue financiado por la Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) del gobierno de Chile a través del Proyecto Postdoctoral FONDECYT No. 3170629, Proyectos Regulares FONDECYT No. 1160302, 1141247 y 1181050. Este estudio también fue financiado por Proyecto REDES ETAPA INICIAL, Convocatoria 2017. REDI170334.

10.3389/fmicb.2018.01155

pdf

phosphobacteria# organic acids# phosphatases# malate dehydrogenase# acid soils# aluminium-toxicity# phosphorus-deficiency

http://dx.doi.org/10.3389/fmicb.2018.01155

Microbiology

fosfobacterias# ácidos orgánicos# fosfatasas# malato deshidrogenasa# suelos ácidos# toxicidad del aluminio# deficiencia de fósforo

Biotecnología agrícola

Microbiología

Ciencias del suelo

WOS:000433884700001

Understanding the Strategies to Overcome Phosphorus-Deficiency and Aluminum-Toxicity by Ryegrass Endophytic and Rhizosphere Phosphobacteria

Artículo original

version publicada

FRONTIERS MEDIA SA

FRONTIERS IN MICROBIOLOGY

Microbiología

1664-302X

en

ANID FONDECYT Postdoctoral 3170629#ANID FONDECYT 1160302#ANID FONDECYT 1141247#ANID FONDECYT 1181050#ANID REDES ETAPA INICIAL REDI170334

ANID CONICYT 3170629

ANID CONICYT FONDECYT 1160302

ANID CONICYT FONDECYT 1141247

ANID CONICYT FONDECYT 1181050

REDES ETAPA INICIAL REDI170334

This study was financed by the Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) of Chilean government through FONDECYT Postdoctoral Project No. 3170629, FONDECYT Regular Projects No. 1160302, 1141247, and 1181050. This study was also funding by Proyecto REDES ETAPA INICIAL, Convocatoria 2017, REDI170334.

pdf

dorada#verde

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acceso abierto

CC BY

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