Growth promotion and root development of Nicotiana tabacum L. By plant growth promoting fungi (PGPF)

Plant growth-promoting microorganisms promote plant growth by supplying nutrients to roots and interacting with the intrinsic factors in plants through volatile organic compounds (VOCs). In this study, we evaluated the effect of UOS, plant growth-promoting fungi (PGPF) isolated from previous study, on the growth of Nicotiana tabacum L. var Xanthi nc. Phylogenetic analysis and GC-MS were used to identify the fungal species and the VOCs emitted by the UOS, respectively. The fresh weight of UOS-treated Nicotiana tabacum L. was 3.8 and 4.2-fold higher than that of the control groups grown in vertical and I-plates, respectively. Moreover, in the UOS-treated plants, the length of the primary root was half and the number of lateral roots were twice compared to those in control plants. The UOS was identified as Phoma sp. by studying spore and mycelial morphology and using phylogenetic analysis. GC-MS revealed that the VOC emitted by the UOS was hexamethylcyclotrisiloxane (D3). These results suggest that the UOS of Phoma sp. influences plant growth and root development through D3. We expect this UOS and its VOC, D3 to be utilized in the future to increase growth and enhance yield for other plants.