We explored the activation of defense genes and the changes in volatile profiles in olive (Olea europaea var. Picual) plants subjected to mechanical wounding and prior soil inoculation with the fungus Trichoderma afroharzianum T22. Our findings indicate a sustained effect of the inoculant in olive plants, which shifted the constitutive volatile emission more significantly towards an aldehyde-dominated blend than the mechanical damage alone. Furthermore, we found that wounding alone did not alter the expression of hydroperoxide lyase genes associated with aldehyde biosynthesis. However, this expression was significantly enhanced when combined with prior T22 inoculation. Mechanical wounding amplified the plant’s immediate defensive response by enhancing the upregulation of the direct defense enzyme acetone cyanohydrin lyase. Trichoderma afroharzianum T22 also modulated direct defense, although to a lesser extent, and its effect persisted 9 months after inoculation. Metagenomic analyses revealed that aerial mechanical damage did influence specific root bacterial functions. Specifically, an upregulation of predicted bacterial functions related to various metabolic processes, including responses to biotic and abiotic stresses, was observed. On the contrary, T22’s impact on bacterial functional traits was minor and/or transient.

我们探索了遭受机械损伤和事先用真菌木霉T22进行土壤接种的橄榄 ( Olea europaea var. Picual) 植物中防御基因的激活和挥发性成分的变化。我们的研究结果表明，接种剂对橄榄植物具有持续影响，与单独的机械损伤相比，它使本构挥发性排放更显着地转向以醛为主的混合物。此外，我们发现单独受伤并不会改变与醛生物合成相关的氢过氧化物裂解酶基因的表达。然而，当与之前的 T22 接种相结合时，这种表达显着增强。机械伤害通过增强直接防御酶丙酮氰醇裂解酶的上调来放大植物的直接防御反应。非洲木霉T22 也调节直接防御，尽管程度较小，并且其效果在接种后持续 9 个月。宏基因组分析表明，空中机械损伤确实影响特定的根部细菌功能。具体来说，观察到与各种代谢过程相关的预测细菌功能的上调，包括对生物和非生物胁迫的反应。相反，T22 对细菌功能性状的影响较小和/或短暂。