Attachment of different soil bacteria to arbuscular mycorrhizal fungal extraradical hyphae is determined by hyphal vitality and fungal species

Abstract

Attachment of certain bacteria to living arbuscular mycorrhizal fungal extraradical hyphae may be an important prerequisite for interactions between these microorganisms, with implications for nutrient supply and plant health. The attachment of five different strains of gfp-tagged soil bacteria (Paenibacillus brasilensis PB177 (pnf8), Bacillus cereus VA1 (pnf8), Pseudomonas fluorescens SBW25 :: gfp/lux, Arthrobacter chlorophenolicus A6G, and Paenibacillus peoriae BD62 (pnf8)) to vital and nonvital extraradical hyphae of the arbuscular mycorrhizal fungi Glomus sp. MUCL 43205 and Glomus intraradices MUCL 43194 was examined. Arthrobacter chlorophenolicus did not attach to hyphae, whereas the other bacterial strains did to a varying degree. Only P. brasilensis showed greater attachment to vital hyphae than nonvital hyphae of both Glomus species tested. Pseudomonas fluorescens showed a higher attachment to vital compared with nonvital Glomus sp. MUCL 43205 hyphae, whereas this relationship was opposite for attachment to G. intraradices. Both B. cereus and P. peoriae showed higher attachment to nonvital hyphae. This study provides novel evidence that under laboratory conditions soil bacteria differ in their ability to colonize vital and nonvital hyphae and that this can also be influenced by the arbuscular mycorrhizal fungal species involved. The significance of bacterial attachment to mycorrhizal fungal extraradical hyphae is discussed.

Characterisation of microbial communities colonising the hyphal surfaces of arbuscular mycorrhizal fungi

“…Vitality of the hyphae might also have had a role. Toljander et al (2006) found the same B. cereus strain to preferentially attach to nonvital hyphae of G. intraradices. In addition to B. cereus, also Paenibacillus spp.…”

“…Some studies have investigated the ability of bacteria to attach to AMF hyphae, but only using pure and single cultures and sometimes with hyphae that were not connected to plant roots (Bianciotto et al, 1996(Bianciotto et al, , 2001Toljander et al, 2006). Such studies may therefore have been biased towards less active AMF hyphae and non-competitive attachment.…”

“…First, pure cultures of a number of biocontrol, Rhizobium and soil bacteria (for example, Pseudomonas fluorescens, Rhizobium leguminosarum, Paenibacillus brasilensis, Paenibacillus peoriae and Bacillus cereus) are able to attach to AMF hyphae and differences in bacterial attachment have been found between vital and nonvital hyphae (Bianciotto et al, 1996(Bianciotto et al, , 2001Toljander et al, 2006). This suggests that specific AMFbacteria interactions may exist.…”

Diversidad de micorrizas arbusculares en pasto colosuana (Bothriochloa pertusa (L) A. Camus de fincas ganaderas del municipio de Corozal-Sucre

“…Esta interacción son establecidas durante todas la etapas del ciclo de vida de las micorrizas, desde la formación de esporas, germinación, colonización dentro de las raíces de las planta hasta la emisión de las hifas externas (2). Los estudios taxonómicos de HMA, tradicionalmente fueron basados en la morfología y apariencia de las esporas.…”

Spore Associated Bacteria (SAB) of Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth Promoting Rhizobacteria (PGPR) Increase Nutrient Uptake and Plant Growth Under Stress Conditions

“…Xavier and Germida (2003) reported that the spore associated bacteria of Glomus clarum may specifically stimulate spore germination. Although the fungi and its close proximity of bacteria interaction seem logical, little is known about the extent that which bacteria associate with which AMF and their specificity for interaction (Toljander et al, 2005). Scientists have identified and isolated spore associated bacteria from spore surface, inside spore, and around hyphae.…”