Abstract

Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms that may stablish symbiotic association with grapevine roots, improving stress tolerance and plant growth. AMF and PGPR enhance the production of plant secondary metabolites, including volatile organic compounds (VOCs), that are involved in plant-environment interaction and are related to plant defense. The aim of this work was to analyze the effects of AMF and PGPR on root VOC emission in Vitis vinifera cv. Cabernet Sauvignon to gain insight into the potential role of plant-rhizosphere microorganisms in vineyard growth and health. Grapevines were inoculated with the mycorrhizal fungus Funneliformis mosseae IN101 and/or the PGPR Ensifer meliloti TSA41. Fiftyeight VOCs were identified usingheadspace solid-phase microextraction (HS-SPME) coupled to gas chromatography/ mass spectrometry. VOC emission was highly induced by IN101, increasing by 69%,compared with control plants. By contrast, TSA41 only increased VOC emission by 11%. Monoterpenes were strongly enhanced by IN101, increasing by 87% compared with control plants. Interestingly, monoterpene alcohols related to plant defense were increased. Knowledge of the positive effects of AMF and PGPR on grapevine VOCs may lead to their use as bioinoculants in an integrated and sustainable management of vineyards.