C. Azcón-Aguilar - Academia.edu (original) (raw)
Papers by C. Azcón-Aguilar
Environmental microbiology, Jan 11, 2015
Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF... more Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF species differ in terms of propagation strategies and the major propagules they form. This study compared the AMF community composition of different propagule fractions- colonised roots, spores and extraradical mycelium (ERM)-associated with five Mediterranean plant species in Sierra de Baza Natural Park (Granada, Spain). AMF were identified using 454 pyrosequencing of the SSU rRNA gene. A total of 96 AMF phylogroups (virtual taxa, VT) were detected in the study site, including 31 novel VT. After per-sample sequencing depth standardisation, 71 VT were recorded from plant roots, and 47 from each of the spore and ERM fractions. AMF communities differed significantly among the propagule fractions, and the root-colonizing fraction differed among host plant species. Indicator VT were detected for the root (13 Glomus VTs), spore (Paraglomus VT281, VT336, Pacispora VT284) and ERM (Diversispora...
... del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain Javier García-Andrade Departament... more ... del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain Javier García-Andrade Departamento ... y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 ... 118 Route de Narbonne, 31062 Toulouse Cedex 4, France David Genney School ...
Plant Science, 1999
b-1,3-Glucanases in tomato roots were studied after arbuscular mycorrhizal (AM) symbiosis establi... more b-1,3-Glucanases in tomato roots were studied after arbuscular mycorrhizal (AM) symbiosis establishment and/or pathogenic infection by Phytophthora parasitica by polyacrylamide gel electrophoresis (PAGE). Two species of AM fungi, Glomus mosseae and Glomus intraradices were tested, and Phytophthora inoculation was performed on both non-mycorrhizal and mycorrhizal tomato pre-colonized for 4 weeks with either of the AM fungal species. The protective effect of both AM fungi on tomato plants against Phytophthora was assessed. In control roots two acidic b-1,3-glucanase isoforms were constitutively expressed, and their activity was higher in mycorrhizal roots. Two additional acidic isoforms were detected in extracts from G. mosseae-colonized tomato roots, but not in G. intraradices-colonized roots. Roots infected by P. parasitica displayed stronger activities but the pathogen did not induce the isoforms related to G. mosseae colonization. Only one basic glucanase isoform was detected whether the plants were non-inoculated or colonized by any of the fungi when inoculated singly. However, when plants were pre-inoculated with G. mosseae and post-infected with P. parasitica two additional basic isoforms were clearly revealed. Results are discussed in relation to the possible role of the additional acidic and basic b-1,3-glucanase isoforms in the establishment and development of the AM symbiosis, as well as their putative implication in plant bioprotection.
Journal of Experimental Botany, 2000
form mutualistic symbioses with most of the agriculturally important plant species (Barea and Jef... more form mutualistic symbioses with most of the agriculturally important plant species (Barea and Jeffries, 1995). Plant Changes induced by arbuscular mycorrhizal (AM) colonization by the AM fungus and the development of formation in the plasma membrane polypeptide pattern an active symbiosis induces considerable morphological of tomato roots have been assessed by 2D-PAGE and physiological changes in both symbionts (Bonfante analysis. Plasma membrane fractions were isolated by and Perotto, 1995). These changes are presumably the aqueous two-phase partitioning from control and result of a complex sequence of interactions between the mycorrhizal tomato root microsomes. Analysis of fungus and the plant root. As in other plant-microbe 2D-PAGE gels revealed that AM colonization induces systems, it is likely that regulation of these interactions at the plasma membrane level two major changes in requires a continuous exchange of signals between both protein synthesis: down-regulation of some constitupartners, which, when perceived through the correspondtive polypeptides and synthesis of new polypeptides ing receptors, induce a cascade of events leading to or endomycorrhizins. A comparison of changes changes in the expression of certain genes (Koide and induced by two different levels of AM colonization Schreiner, 1992; Boller, 1995). Although the nature of showed that 16 polypeptides were differentially disthose signals and receptors in AM symbiosis is yet played at both AM colonization stages, while some unknown, there is increasing evidence that the AM associothers were transiently regulated. Five of the differenation is controlled by the differential expression of certain tially displayed plasma membrane polypeptides at both genes (Harrison, 1997). AM colonization stages were selected for N-terminal The existence of plant mutants unable to form AM amino acid sequencing. Reliable sequences were symbiosis confirms the hypothesis that specific plant genes obtained for two of the selected spots. Sequence are involved in the establishment of the symbiosis (Duc alignment search indicated that one of the sequenced et al., 1989; Gianinazzi-Pearson et al., 1995; Barker et polypeptides showed 75% identity to the N-terminal al., 1998; Wegel et al., 1998). This has been corraborated sequence of the 69 kDa catalytic subunit of the vacurecently (Samra et al., 1997), when it was shown that the olar type H+-ATPase of several plants. The possible 2D-PAGE pattern of root proteins isolated from the significance of these findings is discussed in relation AM-compatible (wild-type) and the AM-resistant to the functioning of the AM symbiosis. (myc−nod−) pea genotypes were different and that the changes induced by AM colonization in both genotypes Key words: Arbuscular mycorrhizas, plasma membrane, were also very different.
Plant Science, 1999
Arbuscular mycorrhizal (AM) associations are the most common type of plantmicrobe symbiosis invo... more Arbuscular mycorrhizal (AM) associations are the most common type of plantmicrobe symbiosis involved in nutrient cycling in natural ecosystems and in man-made agrosystems [1]. Root colonization by AM fungi induces important physiological and biochemical changes in the host plant, ...
Agronomie, 1996
— The effect of arbuscular mycorrhizal formation on plant development and root system morph... more — The effect of arbuscular mycorrhizal formation on plant development and root system morphogenesis in micropropagated Annona cherimola plants was investigated. A juvenile rootstock was used and already rooted in vitro plantlets were inoculated with arbuscular mycorrhizal propagules at the beginning of their acclimatization phase. Mycorrhization improved plant development (root, steam and leaves), but decreased the specific root length. Arbuscular mycorrhizal formation did not change the degree of branching nor the lateral root frequency for the adventitious roots, but significantly increased the intensity of branching of the first-order laterals. These results corroborate the role of arbuscular mycorrhizal symbiosis inducing beneficial changes in root system morphology and in the general developmental pattern in micropropagated plants. Annona cherimola / arbuscular mycorrhiza / micropropagation / root system morphology Résumé — L'inoculation de mycorhizes arbusculaires augmente la croissance de la plante et change la morphologie du système racinaire d'Annona cherimola Mill micropropagés. L'effet de la formation de mycorhizes arbusculaires sur le développement de la plante et la morphogenèse du système racinaire d'Annona cherimola a été étudié. Un porte-greffe juvénile a été utilisé et des plantes déjà enracinées in vitro ont été inoculées avec des propagules de mycorhizes arbusculaires au début de la période d'acclimatation. La mycorhization améliore le développement de la plante (racines, tiges, feuilles) mais diminue la longueur spécifique des racines. La formation de mycorhizes arbusculaires ne change pas pour les racines adventives, ni le degré d'embranchement, ni la fréquence des racines latérales, mais augmente sensiblement l'intensité des branchements des racines de premier ordre. Ces résultats corroborent le rôle de la symbiose mycorhizienne dans l'induction de changements bénéfiques au niveau de la morphologie du système racinaire et en général du développement de plants micropropagés.
Agronomie, 1996
— Chitinase activities were investigated by native and denaturing SDS-PAGE in tomato roots ... more — Chitinase activities were investigated by native and denaturing SDS-PAGE in tomato roots during symbiosis with the arbuscular mycorrhizal (AM) fungus Glomus mosseae, in a pathogenic interaction with Phytophthora nicotianae var parasitica and in pathogen-infected roots pre-inoculated with G mosseae for 2 weeks. Several native acidic chitinase isoforms were found in control roots. One additional isoform was detected in G mosseae-colonized roots, while a different one was found in pathogen-infected roots, as well as stronger expression of constitutive isoforms. All the chitinase isoforms were found in tomato roots pre-inoculated with G mosseae and post-infected with the pathogen. Four basic isoforms were present in all extracts, but they only showed enhanced activities in pathogeninfected roots. Chitinases from AM roots renatured more quickly and easily than those from non-mycorrhizal roots, after denaturing under non-reducing conditions, even when mycorrhizal plants were post-infected with the pathogen. tomato / Glomus mosseae / Phytophthora nicotianae var parasitica / chitinase bioprotection Résumé — Induction de nouvelles isoformes de chitinase dans les interactions des racines de tomate avec Glomus mosseae et/ou Phytophthora nicotianae var parasitica. Les activités chitinases de racines de tomate en symbiose avec le champignon mycorhizogène Glomus mosseae, dans une interaction pathogène avec Phytophthora nicotianae var parasitica et dans des racines colonisées par G mosseae depuis deux semaines et post-infectées par le pathogène ont été étudiées en gels d'électrophorèse natifs (Page) et dénaturants (SDS-Page). En conditions natives, les racines témoins ont révélé plusieurs isoformes acides de chitinase. Une isoforme additionnelle a été détectée dans les racines colonisées par G mosseae, tandis qu'une isoforme additionnelle différente et une plus forte expression des isoformes constitutives ont été observées dans les racines infectées par le pathogène. Quand les racines étaient mycorhizées puis infectées par le pathogène, l'ensemble des isoformes induites par les deux champignons a été détecté. Sur les quatre isoformes basiques présentes dans tous les extraits, seules les activités des racines infectées par le pathogène étaient stimulées. Après dénaturation en conditions non réductrices, les isoformes de chitinase des racines mycorhizées se sont renaturées plus rapidement et plus facilement que celles des racines non mycorhizées et cela même lorsque les plantes mycorhizées ont été ultérieurement infectées par le pathogène. tomate / Glomus mosseae / Phytophthora nicotianae var parasitica / chitinase bioprotection * Correspondence and reprints
Agriculture, Ecosystems & Environment, 1986
Assessment of field situations for the feasibility of vesicular-arbuscular mycorrhizal inoculatio... more Assessment of field situations for the feasibility of vesicular-arbuscular mycorrhizal inoculation, using a forage legume as test planto Agric. Ecosystems Environ., 15: 241-'252. This paper reports experiments aimed at predicting ecological situations where vesi-cular+arbuscular mycorrhizal (V AM) inoculation would be beneficia!. Twelve unsterile soils were assayed and Hedysarum coronarium, a forage legume, was the test planto Three vesicular-arbuscular endophytes, namely Glomus mosseae, G. fosciculatus and a Glomus sp. were tested, and in all cases G. mosseae was the more efficient, with indications of some plant+fungus specificity. A considerable degree of dependency on mycorrhizas, for suitable growth and N2-fixation, was also demonstrated for the tested legume-Rhizobium sp. system. The studied soils varied in their concentration of plant-available phosphorus and in the amount, infectivity and effectiveness of indigenous VAM propagules; however, no correlation between these parameters could be found. The level of success of the introduction of G. mosseae in the presence of naturally existing endophytes was evaluated by the extent of the plant response in terms of growth , nodulation and N and P uptake in each soi!. The inoculation of G. mosseae was effective in 7 out of the 12 soils; however, it was not possible to find a correlation between any of the soil parameters studied (i.e. soluble P concentration, amount of mycorrhizal root pieces and VAM mycelium and spores) and the plant response to G. mosseae inoculation. Thus, it is necessary to emphasize the need for simple techniques to screen stiuations where it would be worth attempting VAM inoculation, since each particular soil must be checked for each given plant+fungus combination.
Journal of Experimental Botany, 2005
Soil microbial populations are immersed in a framework of interactions known to affect plant fitn... more Soil microbial populations are immersed in a framework of interactions known to affect plant fitness and soil quality. They are involved in fundamental activities that ensure the stability and productivity of both agricultural systems and natural ecosystems. Strategic and applied research has demonstrated that certain cooperative microbial activities can be exploited, as a low-input biotechnology, to help sustainable, environmentally-friendly, agro-technological practices. Much research is addressed at improving understanding of the diversity, dynamics, and significance of rhizosphere microbial populations and their cooperative activities. An analysis of the cooperative microbial activities known to affect plant development is the general aim of this review. In particular, this article summarizes and discusses significant aspects of this general topic, including (i) the analysis of the key activities carried out by the diverse trophic and functional groups of microorganisms involved in cooperative rhizosphere interactions; (ii) a critical discussion of the direct microbe-microbe interactions which results in processes benefiting sustainable agroecosystem development; and (iii) beneficial microbial interactions involving arbuscular mycorrhiza, the omnipresent fungus-plant beneficial symbiosis. The trends of this thematic area will be outlined, from molecular biology and ecophysiological issues to the biotechnological developments for integrated management, to indicate where research is needed in the future.
Applied and Environmental Microbiology, 1999
High concentrations of heavy metals have been shown to adversely affect the size, diversity, and ... more High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving inter...
New Phytologist, 1996
... Nitrogen was then extracted using a modified version of the technique described by Bremner &a... more ... Nitrogen was then extracted using a modified version of the technique described by Bremner & Mulvaney (1982). ... 2b). In the Petri dishes containing the dual culture, G. intraradices hyphae began to cross the plastic barrier separating the culture and the hyphal compartments. ...
HortScience
Micropropagated plantlets of avocado (Persea americana Mill.) exhibit a very slow rate of growth ... more Micropropagated plantlets of avocado (Persea americana Mill.) exhibit a very slow rate of growth during the acclimatization phase, possibly because mycorrhizae are absent. Inoculation of plantlets with the vesicular-arbuscular mycorrhizal fungus Glomus fasciculatum (Thaxter sensu Gerd) Gerd and Trappe improved formation of a well-developed root system that was converted into a mycorrhizal system. Introduction of the mycorrhizal fungus at the time plantlets were transferred from axenic conditions to ex vitro conditions improved shoot and root growth; enhanced the shoot: root ratio; increased the concentration and/or content of N, P, and K in plant tissues; and helped plants to tolerate environmental stress at transplanting. Inclusion of soil as a component of the potting medium appeared to favor mycorrhiza formation and effectiveness. Thus, mycorrhiza formation seems to be the key factor for subsequent growth and development of micropropagated plants of avocado.
Advances in Fungal Biotechnology for Industry, Agriculture, and Medicine, 2004
Page 431. 16 Structural and Functional Genomics of Symbiotic Arbuscular Mycorrhizal Fungi V. Gian... more Page 431. 16 Structural and Functional Genomics of Symbiotic Arbuscular Mycorrhizal Fungi V. Gianinazzi-Pearson, C. Azcon-Aguilar, G. Becard, P. Bonfante, N. Ferrol, P. Franken, A. Gollotte, LA Harrier, L. Lanfranco, and D ...
Mycorrhizal Technology in Agriculture, 2002
... es" 1 Mol Plant Microb Interac 13: 238-241 Smith KP, Goodman RM (1999) Host variatio... more ... es" 1 Mol Plant Microb Interac 13: 238-241 Smith KP, Goodman RM (1999) Host variation for interactions with beneficial plant-associated microbes. Ann Rev Phytopathol 37: 473-491 Page 217. The contribution of arbuscular mycorrhizal fungi to the control of soil-borne plant ...
Journal of soil science and plant nutrition, 2015
Optimizing the turnover and recycling of nutrients, a fundamental issue for the sustainability an... more Optimizing the turnover and recycling of nutrients, a fundamental issue for the sustainability and productivity of agro-ecosystems is depending on the functionality of a framework of plant-soil interactions where microbial populations are involved. Both mutualistic symbionts and saprophytic microorganisms living at the root-soil interfaces, the rhizosphere, or in the plant-associated soil, are recognized as essential drivers of nutrient cycling, availability and capture. Among the mutualistic symbionts, arbuscular mycorrhizal (AM) fungi are one of the most influential groups of soil biota because after establishing the AM symbiosis with most plant species they enhance plant nutrient uptake properties. Saprophytic microorganisms are recognized for their abilities to propel nitrogen (N) fixation and/or phosphorus (P) mobilization, two fundamental processes for sustain plant productivity. Mycorrhiza establishment changes the biological and physical-chemical properties of the rhizosphere, developing the socalled mycorrhizosphere. Particularly relevant is the mycorrhizosphere of legume plants since it also involves the symbiosis with N 2-fixing nodulating rhizobial bacteria. In this overview of mycorrhizosphere interactions related to nutrient cycling, after describing the protagonist microorganisms, the mechanisms responsible for nutrient acquisition by AM-plants are first analyzed. Then, the processes involved in mycorrhizosphere establishment and functions are described. Finally, the achievements derived from managing selected AM fungi and beneficial bacteria interactions (mycorrhizosphere tailoring) are discussed. The use of 15 N and 32 P to elucidate the contribution of the mycorrhizosphere components to plant nutrient acquisition is detailed.
Applied and environmental microbiology, 1982
Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-ar... more Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-arbuscular mycorrhiza, was investigated for phytohormone production. Spores of G. mosseae were axenically germinated in water, and the resultant mycelial growth was assayed by standard procedures for extracting plant hormones from microbial cultures. Paper partition chromatography and specific bioassays were used to separate and identify plant growth-regulating substances. The microorganism synthesized at least two gibberellin-like substances, one with R(f) corresponding in position to authentic gibberellic acid, and four substances with the properties of cytokinins.
Ecology and Applications, 2013
Soil Biology, 2005
... Both of them comprise detrimental, neutral and beneficial bacteria and fungi. Beneficial micr... more ... Both of them comprise detrimental, neutral and beneficial bacteria and fungi. Beneficial microorganisms are involved in many key ecosystem processes. Among them, the biogeochemical cycling of both inorganic and organic nutrients in soil and in the maintenance of soil ...
Diversity and Integration in Mycorrhizas, 2002
Bidirectional nutrient transfer between the plant and the fungus is a key feature of arbuscular m... more Bidirectional nutrient transfer between the plant and the fungus is a key feature of arbuscular mycorrhizal symbiosis. The major nutrients exchanged between the symbiotic partners are reduced carbon, assimilated through the plant photosynthesis and phosphate, taken up by the fungal hyphae exploring soil microhabitats. This nutrient exchange takes place across the symbiotic interfaces which are bordered by the plant and fungal plasma membranes. This review provides an overview of the current knowledge of the mechanisms underlying nutrient transport processes in the symbiosis, with special emphasis on recent developments in the molecular biology of the plant and fungal primary (H +-ATPases) and secondary transporters.
Environmental microbiology, Jan 11, 2015
Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF... more Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF species differ in terms of propagation strategies and the major propagules they form. This study compared the AMF community composition of different propagule fractions- colonised roots, spores and extraradical mycelium (ERM)-associated with five Mediterranean plant species in Sierra de Baza Natural Park (Granada, Spain). AMF were identified using 454 pyrosequencing of the SSU rRNA gene. A total of 96 AMF phylogroups (virtual taxa, VT) were detected in the study site, including 31 novel VT. After per-sample sequencing depth standardisation, 71 VT were recorded from plant roots, and 47 from each of the spore and ERM fractions. AMF communities differed significantly among the propagule fractions, and the root-colonizing fraction differed among host plant species. Indicator VT were detected for the root (13 Glomus VTs), spore (Paraglomus VT281, VT336, Pacispora VT284) and ERM (Diversispora...
... del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain Javier García-Andrade Departament... more ... del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain Javier García-Andrade Departamento ... y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 ... 118 Route de Narbonne, 31062 Toulouse Cedex 4, France David Genney School ...
Plant Science, 1999
b-1,3-Glucanases in tomato roots were studied after arbuscular mycorrhizal (AM) symbiosis establi... more b-1,3-Glucanases in tomato roots were studied after arbuscular mycorrhizal (AM) symbiosis establishment and/or pathogenic infection by Phytophthora parasitica by polyacrylamide gel electrophoresis (PAGE). Two species of AM fungi, Glomus mosseae and Glomus intraradices were tested, and Phytophthora inoculation was performed on both non-mycorrhizal and mycorrhizal tomato pre-colonized for 4 weeks with either of the AM fungal species. The protective effect of both AM fungi on tomato plants against Phytophthora was assessed. In control roots two acidic b-1,3-glucanase isoforms were constitutively expressed, and their activity was higher in mycorrhizal roots. Two additional acidic isoforms were detected in extracts from G. mosseae-colonized tomato roots, but not in G. intraradices-colonized roots. Roots infected by P. parasitica displayed stronger activities but the pathogen did not induce the isoforms related to G. mosseae colonization. Only one basic glucanase isoform was detected whether the plants were non-inoculated or colonized by any of the fungi when inoculated singly. However, when plants were pre-inoculated with G. mosseae and post-infected with P. parasitica two additional basic isoforms were clearly revealed. Results are discussed in relation to the possible role of the additional acidic and basic b-1,3-glucanase isoforms in the establishment and development of the AM symbiosis, as well as their putative implication in plant bioprotection.
Journal of Experimental Botany, 2000
form mutualistic symbioses with most of the agriculturally important plant species (Barea and Jef... more form mutualistic symbioses with most of the agriculturally important plant species (Barea and Jeffries, 1995). Plant Changes induced by arbuscular mycorrhizal (AM) colonization by the AM fungus and the development of formation in the plasma membrane polypeptide pattern an active symbiosis induces considerable morphological of tomato roots have been assessed by 2D-PAGE and physiological changes in both symbionts (Bonfante analysis. Plasma membrane fractions were isolated by and Perotto, 1995). These changes are presumably the aqueous two-phase partitioning from control and result of a complex sequence of interactions between the mycorrhizal tomato root microsomes. Analysis of fungus and the plant root. As in other plant-microbe 2D-PAGE gels revealed that AM colonization induces systems, it is likely that regulation of these interactions at the plasma membrane level two major changes in requires a continuous exchange of signals between both protein synthesis: down-regulation of some constitupartners, which, when perceived through the correspondtive polypeptides and synthesis of new polypeptides ing receptors, induce a cascade of events leading to or endomycorrhizins. A comparison of changes changes in the expression of certain genes (Koide and induced by two different levels of AM colonization Schreiner, 1992; Boller, 1995). Although the nature of showed that 16 polypeptides were differentially disthose signals and receptors in AM symbiosis is yet played at both AM colonization stages, while some unknown, there is increasing evidence that the AM associothers were transiently regulated. Five of the differenation is controlled by the differential expression of certain tially displayed plasma membrane polypeptides at both genes (Harrison, 1997). AM colonization stages were selected for N-terminal The existence of plant mutants unable to form AM amino acid sequencing. Reliable sequences were symbiosis confirms the hypothesis that specific plant genes obtained for two of the selected spots. Sequence are involved in the establishment of the symbiosis (Duc alignment search indicated that one of the sequenced et al., 1989; Gianinazzi-Pearson et al., 1995; Barker et polypeptides showed 75% identity to the N-terminal al., 1998; Wegel et al., 1998). This has been corraborated sequence of the 69 kDa catalytic subunit of the vacurecently (Samra et al., 1997), when it was shown that the olar type H+-ATPase of several plants. The possible 2D-PAGE pattern of root proteins isolated from the significance of these findings is discussed in relation AM-compatible (wild-type) and the AM-resistant to the functioning of the AM symbiosis. (myc−nod−) pea genotypes were different and that the changes induced by AM colonization in both genotypes Key words: Arbuscular mycorrhizas, plasma membrane, were also very different.
Plant Science, 1999
Arbuscular mycorrhizal (AM) associations are the most common type of plantmicrobe symbiosis invo... more Arbuscular mycorrhizal (AM) associations are the most common type of plantmicrobe symbiosis involved in nutrient cycling in natural ecosystems and in man-made agrosystems [1]. Root colonization by AM fungi induces important physiological and biochemical changes in the host plant, ...
Agronomie, 1996
— The effect of arbuscular mycorrhizal formation on plant development and root system morph... more — The effect of arbuscular mycorrhizal formation on plant development and root system morphogenesis in micropropagated Annona cherimola plants was investigated. A juvenile rootstock was used and already rooted in vitro plantlets were inoculated with arbuscular mycorrhizal propagules at the beginning of their acclimatization phase. Mycorrhization improved plant development (root, steam and leaves), but decreased the specific root length. Arbuscular mycorrhizal formation did not change the degree of branching nor the lateral root frequency for the adventitious roots, but significantly increased the intensity of branching of the first-order laterals. These results corroborate the role of arbuscular mycorrhizal symbiosis inducing beneficial changes in root system morphology and in the general developmental pattern in micropropagated plants. Annona cherimola / arbuscular mycorrhiza / micropropagation / root system morphology Résumé — L'inoculation de mycorhizes arbusculaires augmente la croissance de la plante et change la morphologie du système racinaire d'Annona cherimola Mill micropropagés. L'effet de la formation de mycorhizes arbusculaires sur le développement de la plante et la morphogenèse du système racinaire d'Annona cherimola a été étudié. Un porte-greffe juvénile a été utilisé et des plantes déjà enracinées in vitro ont été inoculées avec des propagules de mycorhizes arbusculaires au début de la période d'acclimatation. La mycorhization améliore le développement de la plante (racines, tiges, feuilles) mais diminue la longueur spécifique des racines. La formation de mycorhizes arbusculaires ne change pas pour les racines adventives, ni le degré d'embranchement, ni la fréquence des racines latérales, mais augmente sensiblement l'intensité des branchements des racines de premier ordre. Ces résultats corroborent le rôle de la symbiose mycorhizienne dans l'induction de changements bénéfiques au niveau de la morphologie du système racinaire et en général du développement de plants micropropagés.
Agronomie, 1996
— Chitinase activities were investigated by native and denaturing SDS-PAGE in tomato roots ... more — Chitinase activities were investigated by native and denaturing SDS-PAGE in tomato roots during symbiosis with the arbuscular mycorrhizal (AM) fungus Glomus mosseae, in a pathogenic interaction with Phytophthora nicotianae var parasitica and in pathogen-infected roots pre-inoculated with G mosseae for 2 weeks. Several native acidic chitinase isoforms were found in control roots. One additional isoform was detected in G mosseae-colonized roots, while a different one was found in pathogen-infected roots, as well as stronger expression of constitutive isoforms. All the chitinase isoforms were found in tomato roots pre-inoculated with G mosseae and post-infected with the pathogen. Four basic isoforms were present in all extracts, but they only showed enhanced activities in pathogeninfected roots. Chitinases from AM roots renatured more quickly and easily than those from non-mycorrhizal roots, after denaturing under non-reducing conditions, even when mycorrhizal plants were post-infected with the pathogen. tomato / Glomus mosseae / Phytophthora nicotianae var parasitica / chitinase bioprotection Résumé — Induction de nouvelles isoformes de chitinase dans les interactions des racines de tomate avec Glomus mosseae et/ou Phytophthora nicotianae var parasitica. Les activités chitinases de racines de tomate en symbiose avec le champignon mycorhizogène Glomus mosseae, dans une interaction pathogène avec Phytophthora nicotianae var parasitica et dans des racines colonisées par G mosseae depuis deux semaines et post-infectées par le pathogène ont été étudiées en gels d'électrophorèse natifs (Page) et dénaturants (SDS-Page). En conditions natives, les racines témoins ont révélé plusieurs isoformes acides de chitinase. Une isoforme additionnelle a été détectée dans les racines colonisées par G mosseae, tandis qu'une isoforme additionnelle différente et une plus forte expression des isoformes constitutives ont été observées dans les racines infectées par le pathogène. Quand les racines étaient mycorhizées puis infectées par le pathogène, l'ensemble des isoformes induites par les deux champignons a été détecté. Sur les quatre isoformes basiques présentes dans tous les extraits, seules les activités des racines infectées par le pathogène étaient stimulées. Après dénaturation en conditions non réductrices, les isoformes de chitinase des racines mycorhizées se sont renaturées plus rapidement et plus facilement que celles des racines non mycorhizées et cela même lorsque les plantes mycorhizées ont été ultérieurement infectées par le pathogène. tomate / Glomus mosseae / Phytophthora nicotianae var parasitica / chitinase bioprotection * Correspondence and reprints
Agriculture, Ecosystems & Environment, 1986
Assessment of field situations for the feasibility of vesicular-arbuscular mycorrhizal inoculatio... more Assessment of field situations for the feasibility of vesicular-arbuscular mycorrhizal inoculation, using a forage legume as test planto Agric. Ecosystems Environ., 15: 241-'252. This paper reports experiments aimed at predicting ecological situations where vesi-cular+arbuscular mycorrhizal (V AM) inoculation would be beneficia!. Twelve unsterile soils were assayed and Hedysarum coronarium, a forage legume, was the test planto Three vesicular-arbuscular endophytes, namely Glomus mosseae, G. fosciculatus and a Glomus sp. were tested, and in all cases G. mosseae was the more efficient, with indications of some plant+fungus specificity. A considerable degree of dependency on mycorrhizas, for suitable growth and N2-fixation, was also demonstrated for the tested legume-Rhizobium sp. system. The studied soils varied in their concentration of plant-available phosphorus and in the amount, infectivity and effectiveness of indigenous VAM propagules; however, no correlation between these parameters could be found. The level of success of the introduction of G. mosseae in the presence of naturally existing endophytes was evaluated by the extent of the plant response in terms of growth , nodulation and N and P uptake in each soi!. The inoculation of G. mosseae was effective in 7 out of the 12 soils; however, it was not possible to find a correlation between any of the soil parameters studied (i.e. soluble P concentration, amount of mycorrhizal root pieces and VAM mycelium and spores) and the plant response to G. mosseae inoculation. Thus, it is necessary to emphasize the need for simple techniques to screen stiuations where it would be worth attempting VAM inoculation, since each particular soil must be checked for each given plant+fungus combination.
Journal of Experimental Botany, 2005
Soil microbial populations are immersed in a framework of interactions known to affect plant fitn... more Soil microbial populations are immersed in a framework of interactions known to affect plant fitness and soil quality. They are involved in fundamental activities that ensure the stability and productivity of both agricultural systems and natural ecosystems. Strategic and applied research has demonstrated that certain cooperative microbial activities can be exploited, as a low-input biotechnology, to help sustainable, environmentally-friendly, agro-technological practices. Much research is addressed at improving understanding of the diversity, dynamics, and significance of rhizosphere microbial populations and their cooperative activities. An analysis of the cooperative microbial activities known to affect plant development is the general aim of this review. In particular, this article summarizes and discusses significant aspects of this general topic, including (i) the analysis of the key activities carried out by the diverse trophic and functional groups of microorganisms involved in cooperative rhizosphere interactions; (ii) a critical discussion of the direct microbe-microbe interactions which results in processes benefiting sustainable agroecosystem development; and (iii) beneficial microbial interactions involving arbuscular mycorrhiza, the omnipresent fungus-plant beneficial symbiosis. The trends of this thematic area will be outlined, from molecular biology and ecophysiological issues to the biotechnological developments for integrated management, to indicate where research is needed in the future.
Applied and Environmental Microbiology, 1999
High concentrations of heavy metals have been shown to adversely affect the size, diversity, and ... more High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving inter...
New Phytologist, 1996
... Nitrogen was then extracted using a modified version of the technique described by Bremner &a... more ... Nitrogen was then extracted using a modified version of the technique described by Bremner & Mulvaney (1982). ... 2b). In the Petri dishes containing the dual culture, G. intraradices hyphae began to cross the plastic barrier separating the culture and the hyphal compartments. ...
HortScience
Micropropagated plantlets of avocado (Persea americana Mill.) exhibit a very slow rate of growth ... more Micropropagated plantlets of avocado (Persea americana Mill.) exhibit a very slow rate of growth during the acclimatization phase, possibly because mycorrhizae are absent. Inoculation of plantlets with the vesicular-arbuscular mycorrhizal fungus Glomus fasciculatum (Thaxter sensu Gerd) Gerd and Trappe improved formation of a well-developed root system that was converted into a mycorrhizal system. Introduction of the mycorrhizal fungus at the time plantlets were transferred from axenic conditions to ex vitro conditions improved shoot and root growth; enhanced the shoot: root ratio; increased the concentration and/or content of N, P, and K in plant tissues; and helped plants to tolerate environmental stress at transplanting. Inclusion of soil as a component of the potting medium appeared to favor mycorrhiza formation and effectiveness. Thus, mycorrhiza formation seems to be the key factor for subsequent growth and development of micropropagated plants of avocado.
Advances in Fungal Biotechnology for Industry, Agriculture, and Medicine, 2004
Page 431. 16 Structural and Functional Genomics of Symbiotic Arbuscular Mycorrhizal Fungi V. Gian... more Page 431. 16 Structural and Functional Genomics of Symbiotic Arbuscular Mycorrhizal Fungi V. Gianinazzi-Pearson, C. Azcon-Aguilar, G. Becard, P. Bonfante, N. Ferrol, P. Franken, A. Gollotte, LA Harrier, L. Lanfranco, and D ...
Mycorrhizal Technology in Agriculture, 2002
... es" 1 Mol Plant Microb Interac 13: 238-241 Smith KP, Goodman RM (1999) Host variatio... more ... es" 1 Mol Plant Microb Interac 13: 238-241 Smith KP, Goodman RM (1999) Host variation for interactions with beneficial plant-associated microbes. Ann Rev Phytopathol 37: 473-491 Page 217. The contribution of arbuscular mycorrhizal fungi to the control of soil-borne plant ...
Journal of soil science and plant nutrition, 2015
Optimizing the turnover and recycling of nutrients, a fundamental issue for the sustainability an... more Optimizing the turnover and recycling of nutrients, a fundamental issue for the sustainability and productivity of agro-ecosystems is depending on the functionality of a framework of plant-soil interactions where microbial populations are involved. Both mutualistic symbionts and saprophytic microorganisms living at the root-soil interfaces, the rhizosphere, or in the plant-associated soil, are recognized as essential drivers of nutrient cycling, availability and capture. Among the mutualistic symbionts, arbuscular mycorrhizal (AM) fungi are one of the most influential groups of soil biota because after establishing the AM symbiosis with most plant species they enhance plant nutrient uptake properties. Saprophytic microorganisms are recognized for their abilities to propel nitrogen (N) fixation and/or phosphorus (P) mobilization, two fundamental processes for sustain plant productivity. Mycorrhiza establishment changes the biological and physical-chemical properties of the rhizosphere, developing the socalled mycorrhizosphere. Particularly relevant is the mycorrhizosphere of legume plants since it also involves the symbiosis with N 2-fixing nodulating rhizobial bacteria. In this overview of mycorrhizosphere interactions related to nutrient cycling, after describing the protagonist microorganisms, the mechanisms responsible for nutrient acquisition by AM-plants are first analyzed. Then, the processes involved in mycorrhizosphere establishment and functions are described. Finally, the achievements derived from managing selected AM fungi and beneficial bacteria interactions (mycorrhizosphere tailoring) are discussed. The use of 15 N and 32 P to elucidate the contribution of the mycorrhizosphere components to plant nutrient acquisition is detailed.
Applied and environmental microbiology, 1982
Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-ar... more Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-arbuscular mycorrhiza, was investigated for phytohormone production. Spores of G. mosseae were axenically germinated in water, and the resultant mycelial growth was assayed by standard procedures for extracting plant hormones from microbial cultures. Paper partition chromatography and specific bioassays were used to separate and identify plant growth-regulating substances. The microorganism synthesized at least two gibberellin-like substances, one with R(f) corresponding in position to authentic gibberellic acid, and four substances with the properties of cytokinins.
Ecology and Applications, 2013
Soil Biology, 2005
... Both of them comprise detrimental, neutral and beneficial bacteria and fungi. Beneficial micr... more ... Both of them comprise detrimental, neutral and beneficial bacteria and fungi. Beneficial microorganisms are involved in many key ecosystem processes. Among them, the biogeochemical cycling of both inorganic and organic nutrients in soil and in the maintenance of soil ...
Diversity and Integration in Mycorrhizas, 2002
Bidirectional nutrient transfer between the plant and the fungus is a key feature of arbuscular m... more Bidirectional nutrient transfer between the plant and the fungus is a key feature of arbuscular mycorrhizal symbiosis. The major nutrients exchanged between the symbiotic partners are reduced carbon, assimilated through the plant photosynthesis and phosphate, taken up by the fungal hyphae exploring soil microhabitats. This nutrient exchange takes place across the symbiotic interfaces which are bordered by the plant and fungal plasma membranes. This review provides an overview of the current knowledge of the mechanisms underlying nutrient transport processes in the symbiosis, with special emphasis on recent developments in the molecular biology of the plant and fungal primary (H +-ATPases) and secondary transporters.