Plant Growth-Promoting Rhizobacteria Modulate the Concentration of Bioactive Compounds in Tomato Fruits

Abstract

Background: The application of microorganisms as bioestimulants in order to increase the yield and/or quality of agricultural products is becoming a widely used practice in many countries. In this work, five plant growth-promoting rhizobacteria (PGPR), isolated from cultivated rice paddy soils, were selected for their plant growth-promoting capacities (e.g., auxin synthesis, chitinase activity, phosphate solubilisation and siderophores production). Two different tomato cultivars were inoculated, Tres Cantos and cherry. Plants were grown under greenhouse conditions and different phenotypic characteristics were analysed at the time of harvesting. Results: Tres Cantos plants inoculated with PGPR produced less biomass but larger fruits. However, the photosynthetic rate was barely affected. Several antioxidant activities were upregulated in these plants, and no oxidative damage in terms of lipid peroxidation was observed. Finally, ripe fruits accumulated less sugar but, interestingly, more lycopene. By contrast, inoculation of cherry plants with PGPR had no effect on biomass, although photosynthesis was slightly affected, and the productivity was similar to the control plants. In addition, antioxidant activities were downregulated and a higher lipid peroxidation was detected. However, neither sugar nor lycopene accumulation was altered. Conclusion: These results support the use of microorganisms isolated from agricultural soils as interesting tools to manipulate the level of important bioactive molecules in plants. However, this effect seems to be very specific, even at the variety level, and deeper analyses are necessary to assess their use for specific applications.

Synergistic effects of substrate inoculation with Pseudomonas strains on tomato phenology, yield, and selected human health‐related phytochemical compounds

“…The tomato carotene concentration was similar to previous reports by de la Osa et al. (2021) and Ruiz‐Cisneros et al. (2022).…”

“…De la Osa et al. (2021) evaluated Pseudomonas strains for their role in plant development and lycopene content and reported that lycopene content increased by 2.33 and 16.0 mg/100 g FW compared to the NPK control. The antioxidant activity of tomato fruit extracts was measured using DPPH.…”

Biopotential of rhizobacteria to improve growth and phytochemical content in Javanese ginseng (Talinum paniculatum) herbal plant

“…According to Suriani et al (2021), using B. agri at 1-2% can enhance the phenolic content, flavonoids, antioxidant activity, and chlorophyll content in Piper caninum herbal plants. Applying rhizobacteria derived from rice roots on toman cantos plants has enhanced the bioactive lycopene content and antioxidant activity (de la Osa et al, 2021). The combination of PGPR and salicylic acid can improve the levels of secondary metabolites, precisely phenolic compounds and monoterpenes, in Mentha x piperita plants (Del Rosario Cappellari et al, 2020;de la Osa et al, 2021).…”

“…Applying rhizobacteria derived from rice roots on toman cantos plants has enhanced the bioactive lycopene content and antioxidant activity (de la Osa et al, 2021). The combination of PGPR and salicylic acid can improve the levels of secondary metabolites, precisely phenolic compounds and monoterpenes, in Mentha x piperita plants (Del Rosario Cappellari et al, 2020;de la Osa et al, 2021). Inoculating Mucilaginibacter sp.…”

“…Rhizobacteria can also increase growth, phytochemicals, and antioxidants in Piper caninum plants because rhizobacteria can produce IAA hormones, fix nitrogen, and dissolve phosphate, which can increase growth and production in plants (Suriani et al, 2021). Rhizobacteria can also increase growth and biological activity in Lessertia frutescens plants (Hlongwane et al, 2023); likewise, plant growth Plant Growth -Promoting Rhizobacteria (PGPR) can increase lycopene in tomato plants ( de la Osa et al, 2021). (PGPR) can also increase biomass and secondary metabolites in Cannabis sativa plants (Lyu et al, 2023).…”