Laboratório de Ecologia Do Adoecimento E Florestas, Universidade Federal de Ouro Preto-UFOP, Instituto de Ciências Biológicas/NUPEB, Ouro Preto, Minas Gerais, Brazil.
Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
Oecologia. 2021 Apr;195(4):959-970. doi: 10.1007/s00442-021-04878-y. Epub 2021 Feb 25.
Ants have efficient and well-studied social immunity mechanisms, which prevent the colony contamination. Little is known about how workers keep their outside territory clear of diseases. We investigated the interactions between Azteca chartifex ants, their associated bacteria and bacteria on the phyllosphere of Byrsonima sericea trees, comparing plants patrolled and not by the ants. The hypothesis is that bacteria associated with the worker's exoskeleton may outcompete the leaf bacteria. Culturable bacteria were isolated from ants, from the main and satellite nests, and from phyllosphere of B. sericea taken from trees that had A. chartifex nests and from trees without nests. The isolates were grouped by Gram guilds and identified at the genus level. There was a higher percentage of Gram-negative isolates in the ants and on the leaves patrolled by them. There was a higher growth rate of ant bacteria from the main nest compared to those found in ants from the satellite nests. The most representative genus among ant isolates was Enterobacter, also found on leaves patrolled by ants. Under favourable in vitro conditions, A. chartifex Gram-negative bacteria outcompete leaf bacteria by overgrowth, showing a greater competition capacity over the Gram-positive bacteria from leaves with no previous interaction with ants in the field. It was demonstrated that ants carry bacteria capable of outcompeting exogenous bacteria associated with their outside territory. The leaf microbiota of a patrolled tree could be shaped by the ant microbiota, suggesting that large ant colonies may have a key role in structuring canopy plant-microbe interactions.
蚂蚁具有高效且研究充分的社会免疫机制，可防止蚁群受到污染。然而，对于工蚁如何保持其外部领地免受疾病侵害，我们知之甚少。我们研究了阿特卡切叶蚁及其相关细菌与金叶过路黄叶面上细菌之间的相互作用，比较了有蚁群和无蚁群巡逻的植物。我们的假设是，与工蚁外骨骼相关的细菌可能会与叶片细菌竞争。我们从蚂蚁、主巢和卫星巢以及有和没有蚁巢的金叶过路黄树上的叶面上分离出可培养细菌。根据革兰氏菌菌属将分离株进行分组，并在属水平上进行鉴定。在受蚂蚁巡逻的叶片上，革兰氏阴性菌的分离率更高。与从卫星巢中分离出的蚂蚁相比，来自主巢的蚂蚁细菌的生长速度更快。在蚂蚁分离株中，最具代表性的菌属是肠杆菌属，也存在于受蚂蚁巡逻的叶片上。在有利的体外条件下，阿特卡切叶蚁革兰氏阴性菌通过过度生长来竞争叶片细菌，表现出比与蚂蚁在野外无先前相互作用的叶片上的革兰氏阳性细菌更强的竞争能力。实验证明，蚂蚁携带的细菌能够与它们外部领地相关的外源细菌竞争。受巡逻树的叶片微生物群可能会受到蚂蚁微生物群的塑造，这表明大型蚂蚁群体可能在塑造树冠植物-微生物相互作用方面发挥关键作用。
