Document type
Conference papers
Document subtype
Abstract
Title
When fire does not stop symbiosis: Acacia longifolia and its partners.
Participants in the publication
Joana Jesus (Author)
CE3C
Rogério Tenreiro (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
BioISI - Biosystems & Integrative Sciences Institute
Dep. Biologia Vegetal
BioISI
CE3C
Cristina Máguas (Author)
Dep. Biologia Vegetal
CE3C
Helena Trindade (Author)
Dep. Biologia Vegetal
CESAM
Summary
Acacia longifolia is considered nowadays one of the most aggressive invaders. Described as an ecosystemengineer, it has been causing considerable damages, especially when combined with wildfires, which promote germination of an existing seed bank. Acacia expansion is facilitated considering the absence of competitors, and the fact that it is a Leguminosae, where symbiosis is crucial for adaptation and growth. With our study, we aimed to isolate a wider consortium of bacteria that are harboured inside root-nodules, including nitrogen-fixers as well as non-nitrogen fixing bacteria, that we hypothesize could also be living in this symbiosis. Further, we aimed to evaluate the effects of fire in nodulation and bacterial diversity on young plants growing in unburnt and burnt zones, one year after fire. For this we assessed carbon and nitrogen isotopic composition in leaves and nodules, as well as soil analysis. After growth and isolation in YMA media, a collection of cultivable microorganisms was obtained. Further, using M13 fingerprinting and 16S rRNA partial sequencing, we aim to identify genera/species involved in this symbiosis. We found through δ15N isotopic composition in leaves that in unburnt zones, nitrogen fixation seems to contribute more to plant nitrogen content comparing to burnt zones, where soils had more ammonia and nitrates available. Alongside, A. longifolia seems to be promiscuous and despite Bradyrhizobium spp. dominance, Paraburkholderia spp. followed by Pseudomonas spp. were also found. Several species not previously reported as nitrogen-fixers were identified, proposing other functions besides ammonia acquisition ascribed to nodulation. Our study shows that bacterial communities differ in nodules formed after fire, suggesting that fire potentiates nodulation and drives symbiosis towards nitrogen-fixers. Taken together, a multifunctional community belowground inside nodules is pointed out which potentiate A. longifolia invasiveness and adaptation aboveground.
Date of Submisson/Request
2020-09-11
Date of Publication
2020-09-11
Event
Neobiota, 11th International Conference on Biological Invasions, September 15-18 Croatia
Publication Identifiers
Address
Vodice, Croatia.
Organizers
Neobiota, 11th International Conference on Biological Invasions, September 15-18
Publisher
Neobiota