Characterisation and pathogenicity of bacteria from shoot tips of the globe artichoke (Cynara scolymus L.)

Abstract

Bacteria have been isolated from shoot tips of symptomless globe artichoke plants. These were identified as Pseudomonas fluorescens, Pseudomonas marginalis, Pseudomonas spp., Serratia liquefaciens, Enterobacter agglomeransl Erwinia, Agrobacteriurn radiobacter, an unidentified member of Rhizobiaceae and another classified in the "corynebacteria" group. The most frequently isolated species was P. Puorescens, biovars I1 and 111. The endogenous character of these bacteria was studied in plants growing in uitro and in the open field. P. puorescens, P. marginalis, S. liquefaciens and E. agglomeransl Erwinia caused symptoms in plants growing in uitro, but only P. fluorescens biovar I1 and P. marginalis produced symptoms in plants growing in open fields. Differences in pathogenicity were observed on inoculated plants growing in vitro or in the open field. This suggests that several endophytic bacterial species may be responsible for the high levels of contaminants found during the micropropagation of globe artichoke. on Pseudomonas syringae pathovars, Sounion, Greece, pp. 55-57. Mededelingen van de Faculteit Landbouwwetenschappen Rijksuniversiteit Gent 48: 1-1 1. 51' R PENALVER. N DURAN-VILA A N D M M L O P E Z Bradbury J F. 1984. Genus 11. Xutithortiorias Dowson 1939. I n Rergey's Manual of Systematic de Boer S H, Copeman R J. 1974. Endophytic bacterial flora in Solanitin titberosiitn and its significance Cother E J. 1987. A note of the use of Merckoquant test strips for detection of nitrate reduction in Fahy P C , Lloyd A 3. 1983. The fluorescent pseudomonads. In Plant Bacterial Diseases. A Diagnostic Gagne S, Richard C, Antoun H. 1989. Pouvoir pathogene des bacteries endoracinaires de la luzerne. Gardner J M, Chandler J L, Feldman A W. 1985. Growth responses and vascular plugging of citrus Hollis J P. 1951. Bacteria in healthy potato tissue. Ph,~~opatliology 41:350&366. Hugh R, Leifson E. 1953. The taxonomic significance of fermentative versus oxidative metabolism of carhohvdrates by various Gram bacteria. Joiirnul of Bucteriologg 66:24-26. Jacobs M J , Bugbee W hl, Gabrielson D A. 1985. Enumeration. location, and characterization of endophytic bacteria within sugar beet roots.

Alterations in growth of tissue‐cultured tansy (Tanacetum vulgare L.) treated with antibiotics

“…All bacteria isolated from the in vitro cultures of nine tansy genotypes were Gram-negative which i\ consistent with previous studies showing that the majority (73-88%) of bacterial conlaminant\ in in vh-o plantlets are Gram-negative (Peiialver et al, 1994;Brunner. Echegaray & Rubluo, 1995: Buckley er nl., 1995.…”

“…Delphinium, Gerbera, Hosta and Iris (Leifert, Waites & Nicholas, 1989), Galega orientalis Lam. (Valkonen et al, 1993), Cynara scolymus L. (Peiialver et al, 1994) and Mentha (Buckley et al, 1995). Several studies have shown that bacteria can colonise the vascular tissue (e.g.…”

“…A critical stage in the introduction of plants to tissue culture is to obtain cultures free of microbial contamination. This is particularly problematic when explants are taken from perennial field grown plants (Peiialver, Durn-Vila & Lopez, 1994;Savela & Uosukainen, 1994;Keskitalo, Kanerva & Pehu, 1995). Perennial species often have endophytic microflora which are non-pathogenic under natural growth conditions (Gardner, Feldman & Zablotowicz, 1982;van Doorn, de Stigter, de Witte & Boekestein, 1991;Valkonen, von Heiroth & Savela, 1993), but which under a change of environmental conditions, e.g., the transfer of plants to in vitro culture, can alter the host-microbe interaction and can become pathogenic (Leben, 1972;Misaghi & Donndelinger, 1990;Peiialver et al, 1994).…”

Occurrence and Location of Endophytic Bacteria in Garden and Wild Strawberry

“…Intercellular spaces, vascular systems and even single cells are inhabited by several kinds of bacteria and other microbes. The asymptomatic existence of endophytic bacteria has been reported for many species, e.g., strawberry (Berg et al, 2000;Ferguson et al, 2000;Guinebretiere et al, 1999, Tanprasert andReed, 1997), tomato (Samish et al, 1961), pea (Elvira-Recuenco and van Vuurde, 2000), potato (Sturz et al, 1999), cucumber (Mahaffee and Kloepper, 1997), cotton (Chen et al, 1995), and globe artichoke (Peñalver et al, 1994). Both nonpathogenic and pathogenic bacteria can be present, causing no apparent effect on the plant (Bacon and Hinton, 1997).…”

Isothermal DNA amplification facilitates the identification of a broad spectrum of bacteria, fungi and protozoa in Eleutherococcus sp. plant tissue cultures

“…These microorganisms are introduced into in vitro cultures via explants Waites 1990, 1994), air or humans (Leifert et al 1989;Leifert and Cassells 2001). Endophytic bacteria have been reported to live in protoplast cultures of Discorea (Mantell 1997(Mantell , 1998, callus cultures of Phoenix dactylifera (Leary et al 1986), garlic (Fellner et al 1996), Norway spruce (Ewald et al 2000), Pyrethrum (Bergant et al 2005), embryogenic cultures of Norway spruce (Ewald et al 1997), meristem-tip cultures of Hydrangea (Cassells and Tahmatsidou 1996), shoot cultures of birch (Gordon and Brown 1988), Cynara scolymus (Peńalver et al 1994), mint (Reed et al 1995), Robinia pseudoacacia , Echinacea (Lata et al 2006), papaya (Thomas et al 2007a, b) and in leaves and roots of Zantedeschia aethiopica plantlets (Gunson 1992) and of Vitis vinifera (Thomas and Prakash 2004) under in vitro conditions. Endophytic fungi were found in roots and leaves of micropropagated plants from Bouteloua eriopoda and Atriplex canescens (Barrow et al 2004), in shoot tip cultures of pejibaye (de Almeida et al 2005), apple (Kolozsvári-Nagy et al 2005) and in suspension cell cultures of B. eriopoda (Lucero et al 2008).…”