Detection of siderophores in endophytic bacteria Methylobacterium spp. associated with Xylella fastidiosa subsp. pauca

Abstract

-The objective of this work was to study the production of siderophores by endophytic bacteria Methylobacterium spp., which occupy the same ecological niche as Xylella fastidiosa subsp. pauca (Xfp) in citrus plants. The siderophore production of Methylobacterium strains was tested according to chromeazurol agar assay test (CAS), Csáky test (hydroxamate-type) and Arnow test (catechol-type). In addition, the ability of Xfp to use siderophores, in vitro, produced by endophytic bacteria as source of iron, was evaluated. All 37 strains of Methylobacterium spp. tested were CAS-positive for siderophore production. Methylobacterium spp. produced hydroxamate-type, but not catechol-type siderophores. In vitro growth of Xfp was stimulated by the presence of supernatant siderophores of endophytic Methylobacterium mesophilicum.Index terms: citrus variegated chlorosis, endophytes, heterologous siderophores, iron, symbionts. Detecção de sideróforos nas bactérias endofíticas

Seleção de bactérias promotoras de crescimento no abacaxizeiro cultivar Vitória durante a aclimatização

“…Os mecanismos de promoção de crescimento pelas bactérias epifíticas e endofíticas incluem diferentes ações, como a fixação biológica de nitrogênio (KuKlinsky-Sobral et al, 2004), solubilização de fosfatos (Chabot et al, 1998;Verma et al, 2001), biossíntese de fito-hormônios (Lucangeli & Bottini, 1997), influência na atividade enzimática da 1-aminociclopropano 1-carboxilato (ACC) deaminase (Rothballer at al., 2008), controle biológico (Byrne et al, 2005), síntese de sideróforos (Lacava et al, 2008) e indução de resistência sistêmica a patógenos na planta hospedeira (Kloepper et al, 1999 Efeitos positivos da inoculação de bactérias promotoras de crescimento foram verificados na abacaxicultura, principalmente quando as bactérias inoculadas também são fixadoras de nitrogênio atmosférico (Weber et al, 2003). Já foram isoladas de abacaxizeiros bactérias diazotróficas pertencentes aos gêneros Burkholderia (Weber et al, 1999), Acetobacter (Tapia-Hernández et al, 2000) e Asaia (Weber et al, 2003).…”

Plant growth promoting and antagonistic properties of endophytic bacteria isolated from domestic apple

“…Lacava et al (2008) reported that many plants are able to use the siderophores produced by bacterial endophytes as main iron source. In addition, siderophores can inhibit the growth of pathogenic microorganisms, therefore they acts as a pathogen biocontrol agent and indirectly stimulate the growth of plant (Glick, 2012).…”

Inside the Plants: Endophytic Bacteria and their Functional Attributes for Plant Growth Promotion

“…Interestingly Methylobacterium spp. found to be positive towards the hydroxamate-type of siderophore production (Csáky assay), but negative towards the catechol-type siderophores production (Arnow assay) (Lacava et al, 2008). Senthilkumar et al, (2009) isolated a total of 137 endophytic bacteria from the surface sterilized root, stem and of soybean and screened their siderophore production ability.…”