Effects of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria on growth and reactive oxygen metabolism of tomato fruits under low saline conditions

Abstract

Land salinization is a major form of land degradation, which is not conducive to the growth and quality of fruits and vegetables. Plant salt tolerance can be enhanced by arbuscular mycorrhizal fungi (AMF) or plant growth-promoting rhizobacteria (PGPR). This study examined the effects of inoculation with PGPR singly or in combination with AMF, on the growth and quality of tomato fruits under low saline conditions. Tomatoes were cultivated in a greenhouse with sterilized soil, inoculated with PGPR, AMF, or co-inoculated with PGPR and AMF, and NaCl solution (1%) was added to the soil. The results indicated that AMF + PGPR decreased the roots and shoot biomass accumulation, and increased the number and fresh biomass in tomato fruits to a certain extent compared with non-inoculated plants. PGPR and AMF mediated the level of reactive oxygen and lipid peroxidation, the accumulation of antioxidants, and the activity of antioxidant enzymes, including proanthocyanidins, flavonoids, ascorbic acid, superoxide dismutase, peroxidase, and total antioxidant capacity. Furthermore, PGPR, AMF, and PGPR + AMF improved the overall osmotic adjustments and accumulation of soluble sugars and soluble proteins. Therefore, the AMF-Funneliformis mosseae and PGPR-Bacillus subtilis can potentially alleviate the adverse effects of salt stress and be applied as a biofertilizer in agricultural practice.

Effects of the synergistic treatments of arbuscular mycorrhizal fungi and trehalose on adaptability to salt stress in tomato seedlings

“…Under salt stress, MDA content was significantly reduced by Tre treatment and the synergistic effects. Different from the results of Zhou ( 52 ), AMF treatment in this study did not significantly reduce the content of MDA. However, the synergistic effects effectively reduced the accumulation of MDA and reduced the toxic effect of salt stress on cells and cell membranes.…”

Localized and systemic effects of arbuscular mycorrhizal fungi on growth, antioxidant defense system, and nutrient uptake of alfalfa under uniform and non-uniform salt stress

“…Hashem et al (2018) demonstrated that AMF symbiosis enhances the activities of antioxidant enzymes such as SOD, POD, and APX, significantly favoring cucumber cultivation by mitigating the negative impacts of salinity stress. Similar results were observed in studies on Lippia alba (Neto et al, 2023), tomato (Zhou et al, 2022), pigeon pea (Pandey and Garg, 2017), and mustard (Sarwat et al, 2016). Our results are consistent with these studies, showing that all mycorrhizal treatments increased activities of SOD, POD, and CAT under both uniform and non-uniform salinity conditions, resulting in lower H2O2 and MDA contents in the leaves compared to non-AMF plants.…”

Rhizophagus irregularis and biochar can synergistically improve the physiological characteristics of saline‐alkali resistance of switchgrass

“…Antioxidant enzymes can help reduce the oxidative stress on cells and maintain the redox balance by removing these ROS. Additionally, some studies have suggested that antioxidant enzymes can also participate in signal transduction pathways, regulating the initiation and modulation of plant stress responses (Liu et al, 2021; Zhou et al, 2022). Meanwhile, Rehman et al (2022) found that the combination of AMF and biochar could increase the contents of C18:1, C18:2, and C18:3 unsaturated fatty acids, SOD, POD and CAT activities, as well as the contents of chlorophyll and carotenoid in wheat under salt stress.…”

“…Antioxidant enzymes can help reduce the oxidative stress on cells and maintain the redox balance by removing these ROS. Additionally, some studies have suggested that antioxidant enzymes can also participate in signal transduction pathways, regulating the initiation and modulation of plant stress responses (Liu et al, 2021;Zhou et al, 2022).…”