Genome-wide analysis of copper, iron and zinc transporters in the arbuscular mycorrhizal fungus Rhizophagus irregularis

Arbuscular mycorrhizal fungi (AMF), belonging to the Glomeromycota, are soil microorganisms that establish mutualistic symbioses with the majority of higher plants. The efficient uptake of low mobility mineral nutrients by the fungal symbiont and their further transfer to the plant is a major feature of this symbiosis. Besides improving plant mineral nutrition, AMF can alleviate heavy metal toxicity to their host plants and are able to tolerate high metal concentrations in the soil. Nevertheless, we are far from understanding the key molecular determinants of metal homeostasis in these organisms. To get some insights into these mechanisms, a genome-wide analysis of Cu, Fe and Zn transporters was undertaken, making use of the recently published whole genome of the AMF Rhizophagus irregularis. This in silico analysis allowed identification of 30 open reading frames in the R. irregularis genome, which potentially encode metal transporters. Phylogenetic comparisons with the genomes of a set of reference fungi showed an expansion of some metal transporter families. Analysis of the published transcriptomic profiles of R. irregularis revealed that a set of genes were up-regulated in mycorrhizal roots compared to germinated spores and extraradical mycelium, which suggests that metals are important for plant colonization.This research was supported by the Spanish Ministry of Economy and Competitivity (Project AGL2012-35611). Elisabeth Tamayo was supported by a Ph.D. contract (I3P) from the Spanish National Research Council (CSIC) and Tamara Gómez-Gallego by a Ph.D. contract from the Spanish Ministry of Economy and Competitivity.Peer reviewedPeer Reviewe

Effect of Arbuscular Mycorrhizal Colonization on Cadmium‐Mediated Oxidative Stress in Glycine max (L.) Merr.

Cadmium is a heavy metal (HM) that inhibits plant growth and leads to death, causing great losses in yields, especially in Cd hyperaccumulator crops such as Glycine max (L.) Merr. (soybean), a worldwide economically important legume. Furthermore, Cd incorporation into the food chain is a health hazard. Oxidative stress (OS) is a plant response to abiotic and biotic stresses with an intracellular burst of reactive oxygen species (ROS) that causes damage to lipids, proteins, and DNA. The arbuscular mycorrhizal fungal (AMF) association is a plant strategy to cope with HM and to alleviate OS. Our aim was to evaluate the mitigation effects of mycorrhization with AMF Rhizophagus intraradices on soybean growth, nutrients, Cd accumulation, lipid peroxidation, and the activity of different antioxidant agents under Cd (0.7–1.2 mg kg−1 bioavailable Cd) induced OS. Our results suggest that glutathione may act as a signal molecule in a defense response to Cd-induced OS, and mycorrhization may avoid Cd-induced growth inhibition and reduce Cd accumulation in roots. It is discussed that R. intraradices mycorrhization would act as a signal, promoting the generation of a soybean cross tolerance response to Cd pollution, therefore evidencing the potential of this AMF association for bioremediation and encouragement of crop development, particularly because it is an interaction between a worldwide cultivated Cd hyperaccumulator plant and an AMF–HM–accumulator commonly present in soils.Fil: Molina, Alicia Susana. Universidad Nacional de San Luis; ArgentinaFil: Lugo, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Pérez Chaca, María V.. Universidad Nacional de San Luis; ArgentinaFil: Vargas Gil, Silvina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zirulnik, Fanny. Universidad Nacional de San Luis; ArgentinaFil: Leporati, Jorge Leandro. Universidad Nacional de San Luis; ArgentinaFil: Ferrol, Nuria. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Azcón González de Aguilar, Concepción. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; Españ

Arbuscular mycorrhizal fungi from acidic soils favors production of tomatoes and lycopene concentration

This study was supported by FONDECYT 11170641 and MEC80190060 (P. Aguilera), MEC 80180077 (A. Seguel), from Agencia Nacional de Investigación y Desarrollo (ANID, Chile

Mycorrhizas and plant stress

Conferencia presentada en: International Seminar: Soil fertility in times of climate change. Temuco Chile. 25 noviembre (2022

Fertilizantes microbianos : interacciones de Rhizobium y hongos de las micorrizas V-A en la formación y eficacia de sus respectivas simbiosis con leguminosas

Universidad de Granada, Facultad de Ciencias. Leída 07-01-198

Mycorrhizosphere interactions to improve plant fitness and soil quality

Arbuscular mycorrhizal fungi are key components of soil microbiota and obviously interact with other microorganisms in the rhizosphere, i.e. the zone of influence of plant roots on microbial populations and other soil constituents. Mycorrhiza formation changes several aspects of plant physiology and some nutritional and physical properties of the rhizospheric soil. These effects modify the colonization patterns of the root or mycorrhizas (mycorrhizosphere) by soil microorganisms. The rhizosphere of mycorrhizal plants, in practice a mycorrhizosphere, harbors a great array of microbial activities responsible for several key ecosystem processes. This paper summarizes the main conceptual principles and accepted statements on the microbial interactions between mycorrhizal fungi and other members of rhizosphere microbiota and discusses current developments and future trends concerning the following topics: (i) effect of soil microorganisms on mycorrhiza formation; (ii) mycorrhizosphere establishment; (iii) interactions involved in nutrient cycling and plant growth; (iv) interactions involved in the biological control of plant pathogens; and (v) interactions to improve soil quality. The main conclusion is that microbial interactions in the rhizosphere of mycorrhizal plants improve plant fitness and soil quality, critical issues for a sustainable agricultural development and ecosystem functioning.This work was supported by CICyT-FEDER (1FD970763-CO3-02 project), Spain and the ECO-SAFE (QLRT-1999-31759 project) UE.Peer reviewe

Mycorrhizosphere interactions to improve a sustainable production of legumes

The sustainability and productivity of agroecosystems depends exquisitely on the functionality of a framework of plant–soil interactions where microbial populations, including both mutualistic symbionts and saprophytic microorganisms, living at the root–soil interfaces, the rhizosphere, are involved. Among various beneficial and consumable plant species, legumes form useful symbiotic relationships with two types of soil microbiota: N2-fixing bacteria, often called rhizobia, and arbuscular mycorrhizal (AM) fungi. Also, the legume rhizosphere inhabits other valuable microbes such as plant growth-promoting rhizobacteria (PGPR). These microorganisms interact intensely among themselves, and with legume roots, to develop the multifunctional legume mycorrhizosphere, a microcosm environment of variable activities, appropriate for legume productivity. This chapter highlights (1) the types of microorganisms and processes involved in the establishment and functioning of the mycorrhizosphere, (2) the impact of the mycorrhizosphere activities on legume production, and (3) the possibilities to tailor an efficient mycorrhizosphere as a biotechnological tool to improve legume performance in different production systems following efficient rhizobial, PGPR, and AM fungal inoculants.This research was supported by the Andalusian Research Programme (Project CVI-7640) and the Spanish National Research Programme (R & D)-European Union (Feder) (Project CGL2015-69118-C2-2-P).Peer reviewe

Co-inoculation of arbuscular mycorrhizal fungi and pgpr to promote plant nutriention and health

Trabajo presentado al III Taller Latinoamericano de PGPR, celebrado en Chile del 28 de noviembre al 2 de diciembre de 2016.Peer reviewe

21 Vesicular-arbuscular mycorrhizal fungi in nitrogen-fixing systems

The microbial interactions concerning vesicular-arbuscular mycorrhiza or vesicular-arbuscular mycorrhizal fungi and nitrogen-fixing bacteria are of relevance because they can improve plant establishment, development and nutrient acquisition. Taking this into account, two main groups of experimental approaches can be distinguished: (1) studies concerning the establishment of micro-organisms in the rhizosphere (or mycorrhizosphere) and (2) manipulation of these microbial association as a biotechnological tool to improve plant growth. It is well known that a range of soil bacteria possess the ability to cycle nitrogen from the atmosphere to the biosphere by means of the so-called nitrogen-fixing process. All of these bacteria (with the exception of Sesbania sp., which also nodulates on stems) live either in the endorhizosphere (forming root nodules), in intimate association with the root surface or rhizoplane, or in the rhizosphere. Therefore, they must coexist with vesicular-arbuscular mycorrhizal fungi and/or vesiculararbuscular mycorrhiza in the ecosystem. Coexistence commonly involves interaction and there is evidence that such interactions occur, either at the colonization and/or at the functional and nutritional levels. The chapter describes experiments to assess the determinants of symbiotic functional compatibility for particular fungus-plant bacteria-environment combinations.Peer reviewe

Co-inoculation of AM fungi and PGPR for helping plant developments in either low-nutrient or heavy metal contaminated soils

Resumen del trabajo presentado a la 6th International Conference on Mycorrhiza: "Beyond the Roots", celebrada en Belo Horizonte (Brasil) del 9 al 14 de agosto de 2009.Peer reviewe