Plant defense responses induced by arbuscular mycorrhizal fungi

2002 ◽  
pp. 103-111 ◽  
Author(s):  
M. J. Pozo ◽  
S. Slezack-Deschaumes ◽  
E. Dumas-Gaudot ◽  
S. Gianinazzi ◽  
C. Azcón-Aguilar
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Plant Defense ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
Plant Defense Responses

scholarly journals Señales de reconocimiento entre plantas y hongos formadores de micorrizas arbusculares

2010 ◽  
Vol 11 (1) ◽  
pp. 53 ◽  
Author(s):  
Margarita Ramírez Gómez ◽  
Alia Rodríguez Villate
Keyword(s):  
Plant Defense ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Ecosystems ◽  
Defense Responses ◽  
Plant Responses ◽  
Nutrient Exchange ◽  
Mycorrhizal Association ◽  
Host Defense System ◽  
Plant Families

<p>La asociación entre Hongo formadores de micorrizas arbusculares (HFMA) y las plantas ha permitido la adaptación de éstas a ecosistemas terrestres, presentándose en más del 80% de las plantas. El hospedero suministra carbohidratos al hongo y éste transporta los nutrientes que la planta requiere. El establecimiento de la simbiosis requiere procesos armónicos a nivel espacio-temporal, que dependen de señales específicas, para reconocimiento, colonización e intercambio de nutrientes. Las plantas presentan respuestas de defensa frente a la posible invasión de microorganismos, sin embargo, en la simbiosis éstas son débiles, localizadas y no impiden la colonización del hongo. Estas señales se observan en todas las etapas de la simbiosis, siendo la primera señal enviada por la planta en exudados de la raíz, especialmente en condiciones de bajo fósforo. Posteriormente los HFMA activan la expresión de genes que favorecen cambios a nivel celular para la formación del apresorio, del aparato de pre-penetración y en células de la corteza, del arbúsculo y la membrana periarbuscular, para el intercambio de nutrientes. Un aspecto de interés está relacionado con los mecanismos de atenuación de las respuestas de defensa de la planta. Se han planteado diversas hipótesis para entender este fenómeno y aunque el control de la simbiosis está regulado principalmente por la planta, aún se desconoce si los HFMA generan señales que facilitan el debilitamiento de las respuestas de defensa del hospedero. Este documento está orientado a hacer una revisión de las señales de reconocimiento HFMA - plantas para cada fase de la simbiosis, así como de algunos mecanismos de regulación de las respuestas de defensa de la planta para el establecimiento de la simbiosis.</p><p> </p><p><strong>Recognition Signalling Between Arbuscular Mycorrhizal Fungi (AMF) and Plants</strong></p><p> </p>The arbuscular mycorrhizal association has been instrumental for plant adaptation to terrestrial ecosystems over the last 400 million years. It is known that more than 80% of plant families form this symbiosis .Thus, nutrient exchange and protection from pathogens are thought to be key elements in the symbiosis. For the establishment of the association, harmonic processes for recognition, colonization and nutrients exchange are required both at temporal and space level. Plants react against microorganisms attack by producing defense responses, however, in the case of AM association, plant responses are weak, localized and do not stop colonization by the fungus. Signals are observed along the whole symbiosis process, being the first one produced by the plant through root exudates as a response for P stress. Then, AMF activate genes involved in plant cellular changes required for arbuscle formation, pre-penetration apparatus and at cortex level, the formation of periarbuscular membrane for the bi-directional nutrient exchange. Interestingly, several hypotheses have been formulated to explain the plant defense attenuation. For example, the activation of defense suppressors, the existence of plants with no defence responses to AMF and the existence of plants that suppress their defense response, among others. It is unknown whether the fungi induce low response levels from the host defense system. This document focuses on the signaling recognition between AMF and plants in each symbiosis phase and on the regulation mechanisms of the plant defense responses for the symbiosis establishment.

Arbuscular Mycorrhizal Colonization and Activation of Plant Defense Responses Against Phytopathogens

2019 ◽  
pp. 219-240
Author(s):  
Anupam Maharshi ◽  
Gagan Kumar ◽  
Arpan Mukherjee ◽  
Richa Raghuwanshi ◽  
Harikesh Bahadur Singh ◽  
...  
Keyword(s):  
Plant Defense ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
Mycorrhizal Colonization ◽  
Plant Defense Responses ◽  
Arbuscular Mycorrhizal Colonization

scholarly journals Arbuscular mycorrhizal fungi and the occurrence of flavonoids in roots of passion fruit seedlings

2005 ◽  
Vol 62 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Ana Cristina Fermino Soares ◽  
Marco Antônio Martins ◽  
Lêda Mathias ◽  
Marta Simone Mendonça Freitas
Keyword(s):  
Nutritional Status ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
High Performance ◽  
Root Colonization ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
Passion Fruit ◽  
Mycorrhizal Symbiosis ◽  
Methanolic Extracts

Composition and the role of root flavonoids in the regulation of mycorrhizal symbiosis are still poorly understood. Several flavonoids stimulate spore germination, mycelia growth and root colonization by arbuscular mycorrhizal fungi (AMF), and both root colonization and flavonoid composition are affected by plant nutritional status. Effects of AMF on the occurrence and content of aromatic secondary metabolites in the roots of passion fruit seedlings grown under two levels of phosphorus (P) fertilization (10 and 50 mg kg-1 of phosphorus) was studied. Seedlings were inoculated with Glomus clarum and a population of native fungi from a passion fruit plantation. Methanolic extracts of passion fruit seedlings roots were analyzed by high performance liquid chromatography (HPLC). It was recorded the occurrence of several compounds, possibly flavonoids, with seven major peaks. The root contents of the compound with a retention time of 4.5 minutes, varied in response to the root colonization by different mycorrhizal fungi, and the contents of two compounds with retention times of 3.4 and 18.9 minutes varied due to the poor plant growth and nutritional status. Passion fruit seedlings have several aromatic compounds, and their contents were correlated with root colonization by different mycorrhizal fungi, the reduced seedling growth due to nutritional stress, and/or the plant defense responses to the fungi.

scholarly journals Induction of defense responses in common bean plants by arbuscular mycorrhizal fungi

2011 ◽  
Vol 166 (4) ◽  
pp. 268-281 ◽  
Author(s):  
G.M. Abdel-Fattah ◽  
S.A. El-Haddad ◽  
E.E. Hafez ◽  
Y.M. Rashad
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Common Bean ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
Bean Plants ◽  
Common Bean Plants

scholarly journals Synergy between endophytic Bacillus amyloliquefaciens GGA and arbuscular mycorrhizal fungi induces plant defense responses against white rot of garlic and improves host plant growth

2020 ◽  
Vol 59 (1) ◽  
pp. 169-186
Author(s):  
Younes M. RASHAD ◽  
Mohamed A. ABBAS ◽  
Hoda M. SOLIMAN ◽  
Ghada ABDEL-FATTAH ◽  
Gamal ABDEL-FATTAH
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Bacillus Amyloliquefaciens ◽  
Disease Incidence ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
White Rot ◽  
Growth And Yield ◽  
Total Phenol Content ◽  
Sclerotium Cepivorum

White rot, caused by Sclerotium cepivorum, is a serious and economically important disease of garlic, which leads to losses in the garlic production in most of the tropical, subtropical and temperate areas. Biocontrol potential of an endophytic Bacillus amyloliquefaciens GGA and/or arbuscular mycorrhizal fungi (AMF) against this disease was investigated. The B. amyloliquefaciens GGA exhibited antagonistic activity against S. cepivorum in vitro. Scanning electron microscopy revealed alterations in the morphology of the pathogen in response to the exposure to the bacterial metabolites. Results from a pot experiment demonstrated that application of the dual treatment of the B. amyloliquefaciens GGA and AMF reduced disease incidence and severity more than the single treatments, and led to the greatest increases in total phenol content, activities of the defense-related enzymes phenylalanine ammonia-lyase, polyphenoloxidase and peroxidase, and transcriptional expression levels of the defensin and chitinase genes. Growth and yield parameters of garlic plants were enhanced after this treatment. This study showed good efficacy on the tested biocontrol agents for control white rot of garlic plants grown in pots. Future research should evaluate these biocontrol strategies under field conditions.

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