Biocontrol Rhizobacterium Pseudomonas sp. 23S Induces Systemic Resistance in Tomato (Solanum lycopersicum L.) Against Bacterial Canker Clavibacter michiganensis subsp. michiganensis

Las enfermedades de las plantas exacerban el actual déficit de suministro de alimentos. Para defenderse contra infecciones, las plantas responden a moléculas básicas y características de los patógenos llamadas patrones moleculares asociados a patógenos (PAMPs, por sus siglas en inglés), lo que activa respuestas de inmunidad basal conocidas como inmunidad activada por PAMP (PTI, por sus siglas en inglés). Se sabe que la actividad de algunos receptores de reconocimiento de PAMPs se mantiene después de su transferencia entre familias vegetales. El objetivo de este trabajo fue transferir de manera conjunta los genes EFR, FLS2 y BAK1, involucrados en el reconocimiento de PAMPs y en la activación de la PTI en Arabidopsis, a plantas de tomate (Solanum lycopersicum L.), con el fin de generar una resistencia de amplio espectro contra patógenos bacterianos. Para lograrlo se siguió una estrategia basada en la transformación genética de plantas vía Agrobacterium tumefaciens, con un casete de locus sencillo conformado por los genes antes mencionados, retando posteriormente a las plantas transgénicas con bacterias patógenas. Se logró producir plantas de tomate F4 que mostraron un aumento de resistencia a las bacterias en comparación con plantas silvestres; sin embargo, se desconoce la contribución que tuvo cada uno de los genes. Una línea en particular mostró una reducción de cerca de 60, 73 y 83 % de la infección bacteriana cuando fue infectada con Pseudomonas syringae pv. syringae, Pseudomonas syringae pv. tomato y Clavibacter michiganensis subsp. michiganensis, respectivamente. Los resultados sugieren que la expresión heteróloga de múltiples genes involucrados en la PTI bajo el control de un solo promotor puede ser usada para diseñar una resistencia de amplio espectro a patógenos bacterianos en cultivos importantes.

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Attempts at Biological Control of Clavibacter michiganensis subsp. michiganensis On Rockwool-Grown Greenhouse Tomatoes

Vegetable Crops Research Bulletin ◽

10.2478/v10032-008-0027-y ◽

2008 ◽

Vol 69 (1) ◽

pp. 125-134 ◽

Cited By ~ 1

Author(s):

Czesław Ślusarski

Keyword(s):

Biological Control ◽

Biocontrol Agent ◽

Root Zone ◽

First Year ◽

Bacterial Canker ◽

Clavibacter Michiganensis ◽

Tomato Plants ◽

Clavibacter Michiganensis Subsp ◽

Greenhouse Tomatoes ◽

Bacterial Canker Of Tomato

Attempts at Biological Control ofClavibacter michiganensissubsp.michiganensisOn Rockwool-Grown Greenhouse TomatoesTwo greenhouse experiments were conducted in which tomato plants artificially inoculated withClavibacter michiganensissubsp.michiganensis(Cmm) were grown in an open rockwool system as spring and autumn crops. Two isolates of the rhizosphere bacteria,Pseudomonas fluorescensstrain PSR21,Pseudomonas reactansstrain GGS14, a commercial biocontrol agent Aqua Bac Plus (Bacillusspp.) and a proprietary disinfectant containing QAC+Chx, applied at weekly intervals, were evaluated for their efficiency in the suppression of the bacterial canker of tomato. All treatments tested revealed to be ineffective in controlling the disease. The introduction ofCmmbacteria into the fresh rockwool in the first year of its usage resulted in a 100% death of tomato plants, whereas following an artificial inoculation of two- and three-year-old rockwool slabs withCmmbacteria dead plants amounted to 70 and 58%, respectively. This indicates that in the re-used rockwool a natural microbial suppressiveness to bacterial canker of tomato might be developed in the root zone.

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First Record of Clavibacter michiganensis subsp. michiganensis Causing Canker of Tomato Plants in Syria

Plant Disease ◽

10.1094/pdis-92-4-0649c ◽

2008 ◽

Vol 92 (4) ◽

pp. 649-649 ◽

Cited By ~ 4

Author(s):

R. Ftayeh ◽

A. von Tiedemann ◽

B. Koopmann ◽

K. Rudolph ◽

M. Abu-Ghorrah

Keyword(s):

First Record ◽

Bacterial Suspension ◽

Bacterial Canker ◽

Clavibacter Michiganensis ◽

Fresh Market ◽

Gram Positive ◽

Tomato Plants ◽

Clavibacter Michiganensis Subsp ◽

Whole Plants ◽

Bacterial Canker Of Tomato

Between March and mid April of 2007, several extensive surveys for Clavibacter michiganensis subsp. michiganensis were carried out among greenhouses in the coastal strip provinces of the Mediterranean Sea in north-west Syria (Latakia and Tartous), where a large proportion of Syrian fresh-market tomatoes are produced. This bacterium causes bacterial canker of tomato and is considered an A2 quarantine pathogen by the European Plant Protection Organization (EPPO). It is currently present in all major tomato-production areas in the EPPO region (4), but has not been previously reported in Syria. The survey revealed typical canker symptoms in 7% of 150 inspected greenhouses that contained cvs. Dima, Huda, and Astona. These symptoms included stunting, dark brown-to-black lesions on the leaf margins, wilting and defoliation of whole plants, and vascular discoloration. The disease incidence in such greenhouses was estimated at 15% at the time of the survey. Diseased plants were surface sterilized and homogenized in sterile water. Serial dilutions were plated on nutrient glucose agar. Suspected colonies were further purified by repeated restreaking on new agar plates. All 10 of the suspected strains obtained from different locations were identified as C. michiganensis subsp. michiganensis on the basis of the following observations: bacterial cells of all strains had a coryneform shape, were nonmotile, gram positive according to Gram's reaction test with 3% KOH (2), oxidase-negative, and caused hypersensitive reactions on leaves of Mirabilis jalaba (1) within 24 h. PCR assays were conducted with the C. michiganensis subsp. michiganensis-specific primer set PSA-4/R (3) and template DNA prepared from in-vitro-grown bacteria with the MasterPure Gram Positive DNA Purification Kit (Epicentre Biotechnologies, Madison, WI). The expected 270-bp amplicon was observed for both reference strains as well as the Syrian strains. Pathogenicity of the strains was confirmed by artificial inoculation of 6-week-old tomato plants (Lycopersicon esculentum Mill. cv. Lyconorma). Inoculation was performed by stabbing the stem with a sterile needle through a drop (~35 μl) of bacterial suspension (~108 CFU/ml in 0.01 M MgSO4) placed in the axil of the second or third true leaf. Three tomato seedlings were inoculated with each strain. Control plants were inoculated with sterile 0.01 M MgSO4. Symptoms including lateral wilt of leaflets, stem lesions, and wilting of whole plants were observed within 10 to 15 days after inoculation, except for the negative control. To fulfill Koch's postulates, reisolation and reidentification of the pathogen was conducted as previously described. To our knowledge, this is the first record of the occurrence of bacterial canker of tomato in Syria. References: (1) R. D. Gitaitis. Plant Dis. 74:58, 1990. (2) T. J. Gregersen. Appl. Microbiol. Biotechnol. 5:123, 1978. (3) K. H. Pastrik and F. A. Rainey. J. Phytopathol. 147:687, 1999. (4) I. M. Smith and L. M. F. Charles, eds. Map 253 in: Distribution Maps of Quarantine Pests for Europe. EPPO/CABI, 1998.

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