Xanthomonas campestris is a phytopathogenic bacterium and causes many diseases of agricultural relevance. Volatiles were shown to be important in inter- and intraorganismic attraction and defense reactions. Recently it became apparent that also bacteria emit a plethora of volatiles, which influence other organisms such as invertebrates, plants and fungi. As a first step to study volatile-based bacterial–plant interactions, the emission profile of Xanthomonas c. pv. vesicatoria 85-10 was determined by using GC/MS and PTR–MS techniques. More than 50 compounds were emitted by this species, the majority comprising ketones and methylketones. The structure of the dominant compound, 10-methylundecan-2-one, was assigned on the basis of its analytical data, obtained by GC/MS and verified by comparison of these data with those of a synthetic reference sample. Application of commercially available decan-2-one, undecan-2-one, dodecan-2-one, and the newly synthesized 10-methylundecan-2-one in bi-partite Petri dish bioassays revealed growth promotions in low quantities (0.01 to 10 μmol), whereas decan-2-one at 100 μmol caused growth inhibitions of the fungus Rhizoctonia solani. Volatile emission profiles of the bacteria were different for growth on media (nutrient broth) with or without glucose.
Xanthomonas campestris是一种植物病原细菌,引起许多与农业相关的疾病。挥发物被证明在跨和内部有机体的吸引和防御反应中起重要作用。最近,人们意识到细菌也会释放大量挥发物,影响其他生物,如无脊椎动物、植物和真菌。为了研究基于挥发物的细菌-植物相互作用的第一步,利用GC/MS和PTR-MS技术确定了Xanthomonas c. pv. vesicatoria 85-10的排放谱。该物种排放了50多种化合物,其中大部分是酮和甲基酮。通过GC/MS获得的分析数据确定了主要化合物10-甲基十一烷-2-酮的结构,并通过与合成参考样品的数据进行比较进行了验证。在双部分培养皿生物测定中,商业可获得的癸酮、十一酮、十二酮以及新合成的10-甲基十一烷-2-酮在低浓度(0.01至10μmol)下促进了生长,而100μmol的癸酮抑制了真菌Rhizoctonia solani的生长。细菌在含葡萄糖和不含葡萄糖的培养基(营养琼脂)上生长时的挥发物排放谱不同。