Artichoke inoculation with Rhizoglomus irregulare, Funneliformis mosseae, and Trichoderma koningii changes metabolic profile of heads

In many irrigated areas of the southern Mediterranean region, vegetable growers are forced to use saline water to irrigate their crops due to an inadequate supply of fresh water with detrimental effects on crop productivity. In the region of La Vega Baja del Segura, Spain, soil salinity has become an increasing concern for growers producing traditional and sensitive cultivars (Cynara cardunculus L. subsp. scolymus (L.) Hayek) such as ‘Blanca de Tudela’. In these areas, salinity stress of artichoke crop is enhanced by the use of low-quality irrigation water. The aim of the present study was to investigate the effects of inoculation with AMF (Rhizoglomus irregulare BEG72, and Funneliformis mosseae BEG234) and Trichoderma koningii TK7 on metabolic profile of artichoke heads. Seven-week-old artichoke plants grown in a saline soil at Orihuela (Spain) were inoculated through a drip irrigation system using a water suspension containing propagules of AMF (7×105 spores ha-1 of each AMF species) and Trichoderma koningii TK7 (1012 CFU ha-1). The OPLS-DA analysis allowed to discriminate the microbial-inoculated plants from the untreated plants. A total of 105 metabolites were detected and significantly changed. Microbial inoculation induced an hormonal alteration of the plants with a downregulation of cytokinin metabolism, and an up-accumulation of 5 metabolites involved in the jasmonic acid pathway. A decrease of ribulose 5-phosphate was also recorded in microbial-inoculated treatment. Artichoke heads from inoculated plants showed the highest levels of pantothenate (vitamin B5), aminobenzoate (vitamin B9) and pyridoxine (vitamin B6)