Effect of rhizosphere inoculation with Bacillus strains and phytopathogens on the contents of volatiles and human health-related compounds in tomato fruits

Abstract

This study consisted of determining the effect of Bacillus strains inoculated alone or in combination with phytopathogenic fungi on the production of human health-related compounds and volatile organic compounds (VOCs) in tomato fruits. Seedlings were cultivated under greenhouse conditions and inoculated with B. amyloliquefaciens, B. methylotrophicus and B. subtilis alone or in combination with Alternaria solani, Fusarium oxysporum and Phytophthora infestans. Fully ripe fruits were harvested and evaluated for carotenoid, phenol and VOCs contents. Lycopene was the most abundant carotenoid (46.4-167.62 µg/g), followed by β-carotene and lutein. Fruits from plants inoculated with Bacillus had the highest carotenoid content. In contrast, phytopathogens decreased the carotenoid contents, especially the lycopene content. The content of total phenols ranged from 0.42 to 0.90 mg GAE/g. The content of these compounds increased 1.5-fold in fruits from plants inoculated with Bacillus strains, especially those treated with B. methylotrophicus, but the greatest increase (1.9-fold) was observed in plants inoculated with phytopathogens. Both Bacillus strains and pathogens increased the antioxidant capacity, with a 2.8-fold increase compared to the control. Thirty-two VOCs were identified in the tested tomatoes. The Bacillus strains caused an increase in the concentration of VOCs, which could be associated with an increase in fruit quality.

Aroma Volatiles in Tomato Fruits: The Role of Genetic, Preharvest and Postharvest Factors

“…The authors attributed the increase in phenylalanine-derived volatiles to the up-regulation of the phenylpropanoid pathway, producing, in turn, an array of antioxidant compounds modulating the plant's response to root colonization by the AM fungi. Such an interpretation seems coherent with the results of Ruiz-Cisneros et al [96] who subjected the greenhouse tomato 'Merlice' to a root application of Bacillus amyloliquefaciens, B. methylotrophicus and B. subtilis, alone or in combination. The authors reported a PGPR-derived increase in fruit concentration of volatiles having a role as antimicrobials (2-hexenal) or in systemic acquired resistance by the plant (methyl salicylate), together with enhanced concentrations of carotenoids, phenolic acids and associated volatiles.…”

Combined Effect of the Potassium Dose and Plant Biofertilization by Acinetobacter calcoaceticus on the Growth, Mineral Content, Nutritional Quality, Antioxidant Activity, and Metabolomic Features of Tomatillo Fruits (Physalis ixocarpa Brot.)

“…Regarding tomato biofertilization, Ochoa-Velasco et al [ 18 ] reported that the application of the strain B. licheniformis at 75% of the full N dose increased the antioxidant capacity of the fruits for the DPPH (1.9×) and the FRAP (1.4×) assays with respect to the non-inoculated treatment. Similarly, Ruiz-Cisneros et al [ 52 ] reported an increase in the content of phenols (1.5×) and antioxidant activity (2.8×) in tomato fruits biofertilized with Bacillus spp. strains in comparison with the control without inoculation.…”

Effect of thymol on physical properties, antimicrobial properties and fresh-keeping application of cherry tomato of starch/PBAT extrusion blowing films

“…Cherry tomato is popular because of its rich nutrition and juicy taste. However, the postharvest life of this fruit is relatively short, which is limited by postharvest water loss, disease, ripening and aging (Ruiz-Cisneros et al, 2022;Panjai et al, 2017), reducing the acceptance and quality of fruit after storage. Botrytis cinerea is the most common microbial infectious disease of cherry tomato (Wang et al, 2010).…”