Volatile organic compounds (VOCs) produced by Plant Growth Promoting Rhizobacteria have recently been investigated due to their role in plant growth promotion and defense. Whereas some bacterial VOCs like 3-hydroxy-2-butanone (acetoin) and 2,3-butanediol produced by strains of Bacillus subtilis and Bacillus amyloliquefaciens promote plant growth, others like hydrogen cyanide and 3-phenylpropionic acid are phytotoxic, inhibiting plant growth. Bacillus mojavensis, a close relative of B. subtilis, is an endophytic bacterium of maize that has been shown to have antagonistic activity against the mycotoxigenic phytopathogen Fusarium verticillioides and growth promotion activity on maize seedlings. To investigate the growth promotion activity of B. mojavensis, Arabidopsis thaliana seedlings were grown on 1/2x Murashige & Skoog (MS) medium in divided Petri dishes while bacteria were grown either on 1/2x MS or nutrient agar (NA) medium, so that only microbial volatiles reached the seedlings. Significant plant growth promotion in Arabidopsis seedlings was observed when 1/2x MS medium was used for bacterial growth. In contrast, phytotoxicity was observed with bacterial growth on NA medium. These results indicate that VOCs produced by B. mojavensis may act as plant growth modulators rather than just promoters. Using Solid Phase Microextraction (SPME) coupled with GC–MS, the plant growth promoting compounds acetoin and 2,3-butanediol were both identified as being produced by B. mojavensis on growth promoting 1/2x MS medium. In contrast, while no phytotoxic VOC was conclusively identified from B. mojavensis on NA medium, detection of relatively high levels of acetone/2-propanone indicates its possible contribution to Arabidopsis phytotoxicity.

由于促进根瘤菌生长的植物中产生的挥发性有机化合物（VOC）在植物生长促进和防御中的作用，最近已对其进行了研究。而像3-羟基-2-丁酮（乙偶姻）和2,3-丁二醇一些细菌的VOC通过的菌株产生的枯草芽孢杆菌和淀粉液化芽孢杆菌促进植物生长，其他类似的氰化氢和3-苯基丙酸是植物毒性，抑制植物生长。芽孢杆菌摩加夫，近亲枯草芽孢杆菌，是玉米的内生细菌，其已被证明具有抗植物病原体mycotoxigenic拮抗活性串珠镰刀菌和促进玉米幼苗生长的活性。为了研究莫桑比克芽孢杆菌的生长促进活性，拟南芥幼苗在分开培养皿中的1 / 2x Murashige＆Skoog（MS）培养基上生长，而细菌在1 / 2x MS或营养琼脂（NA）培养基上生长，因此只有微生物挥发物才能到达幼苗。当将1 / 2x MS培养基用于细菌生长时，在拟南芥幼苗中观察到显着的植物生长促进作用。相反，在NA培养基上细菌生长时观察到了植物毒性。这些结果表明，莫桑氏芽孢杆菌产生的挥发性有机化合物可能充当植物生长调节剂，而不仅仅是启动子。使用固相微萃取（SPME）结合GC-MS，可以确定植物生长促进化合物丙酮酸和2,3-丁二醇都是由莫来芽孢杆菌在促进生长的1 / 2x MS培养基上产生的。相比之下，虽然在NA培养基上没有从莫来芽孢杆菌中最终鉴定出任何植物毒性的VOC ，但检测到相对较高水平的丙酮/ 2-丙酮表明其可能对拟南芥的植物毒性起作用。