AMIR · Boosting plant defence by Arbuscular Mycorrhizal fungi: Induced Resistance and signalling pathways involved
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-06-01 → 2006-05-31
- EU contribution
- €40,000
- Participants
- 1
- Scheme
- ERG
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Results in brief
Final Activity Report Summary - AMIR (Boosting plant defence by Arbuscular Mycorrhizal fungi: Induced Resistance and signalling pathways involved)
Root colonisation by arbuscular mycorrhizal (AM) fungi can improve plant resistance/tolerance to biotic stresses. Although this bioprotection has been observed in different plant systems, the underlying mechanisms remain largely unknown. In contrast to other types of induced resistance, a direct activation of defence related mechanisms has not been observed. Instead, mycorrhizal plants showed an enhanced capacity to activate defence responses, a phenomenon known as priming. Thus, establishment of mycorrhizal symbiosis seems to boost plant immunity. To investigate the mechanisms and signalling pathways involved in bioprotection by AM fungi, we compared the response of non mycorrhizal and mycorrhizal tomato plants to different defence related signals. Gene expression was monitored in a time course experiment after shoot treatment with the defence related signalling molecules jasmonic (JA), salicylic (SA) acids or ethylene. In mycorrhizal plants a differential regulation of the defence responses triggered was observed. Remarkably, upon JA treatment, shoots of mycorrhizal plants showed up to 10 times higher expression levels of some defence-related genes. We confirmed that this primed response occurs also during interaction with pathogens. A genomic approach has been followed to determine the magnitude of the primed response. In summary, our results evidence differential regulation of defence responses in mycorrhizal plants and point to a prominent role of priming for JA dependent responses in AM-induced resistance. The research constitutes a step forward in our knowledge of plant defence mechanisms and the development of safe, environmentally-friendly and durable strategies for crop protection.
Data: CORDIS, © European Union
Project objective
Plants develop an enhanced defensive capacity against pathogen attack after colonization of the roots by selected strains of arbuscular mycorrhizal fungi (AMF). This induced systemic resistance (ISR) is effective against a broad spectrum of plant pathogens and provides an attractive tool for the development of durable and environmentally friendly strategies for crop protection.Elucidation of the mechanisms by which plants perceive and respond to soil-microorganisms that stimulate their natural defences against pathogens will provide more insight into how plants can be helped to defend themselves against pathogen attack. Different inducible defence mechanisms are found in plants, regulated through a complex network of signalling pathways that involve three molecules: salicylic acid (SA), jasmonic acid (JA) and ethylene (ET).The different pathways enable the plant to fine-tune its resistance reaction to the microorganism encountered. In some systems it has been demonstrated that induced plants show a faster and greater activation of defence responses after infection with a challenging pathogen - a phenomenon called 'potentiation' or 'priming'-. Little is known about the control of the defence responses during the arbuscular mycorrhizal association, and if a potentiation effect occurs during the mycorrhiza-mediated ISR remains unstudied.The present proposal aims to generate knowledge about the genetic control of the plant defence-related processes underlying plant AMF interaction and ISR. Changes in gene express ion under different conditions related to mycorrhizal colonization and induced resistance will be studied using tomato as a model plant and microarray technology.The results will contribute to unravel the signalling pathways and mechanisms involved in the induction of resistance by AMF, with the final goal of improving plant protection by the rational exploitation of natural resources such as beneficial organisms able to boost plant defences.
Original text from CORDIS.
Participants
- CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS · MADRIDCoordinatorSpain
Links
Data: CORDIS, © European Union