How interactions between plants, the rhizosphere, and contaminated soil affect environmental sustainability is still under research. We tested the effects of two root endophytic fungi, the arbuscular mycorrhiza fungus (AMF) Rhizophagus irregularis and the beneficial endophyte Serendipita indica, on sweet basil (Ocimum basilicum) growing on soil contaminated with lead and copper in a pot experiment under defined greenhouse conditions. Both fungi caused an increase in shoot and root dry weight of sweet basil plants under all conditions and decreased the amount of lead in shoots. The amount of copper was reduced by S. indica, while the AM fungus showed this effect only when the soil is contaminated with both copper and lead. Furthermore the AMF, but not the endophyte S. indica caused a strong increase on the concentrations of the essential oils linalool and eucalyptol even on sweet basil growing on contaminated soils. Hence, cultivating sweet basil in combination with beneficial fungi in case of difficult environmental conditions could be of interest for industry located in countries with widespread land pollution, because quantity and quality of plants are increased while the amount of heavy metals is generally reduced.

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Two field experiments were carried out at the farm of Nubaria Agricultural Research Station during the two winter seasons of 2012/2013 and 2013/2014, to study the effect of the arbuscular mycorrhizal fungus, Glomus intraradices and the plant growth promoting rhizobacteria (Biotol) on growth, yield parameters and chemical contents of two wheat cultivars (Sakha 93 and Gemmeza 9) grown in calcareous soil under four levels of soil salinity and four rates of NPK mineral fertilizers. Results indicated that, wheat plants inoculated with AMF and Biotol together significantly decreased Na shoot content (mg/kg), increased NPK uptake, proline and salicylic acid contents, chlorophyll and grain protein at all the tested salinity levels compared to uninoculated plants. Under normal salinity level (≤4 dSm -1), dual inoculation with AMF and Biotol resulted total grain yield to 6.5 and 6.7 t/ha for Sakha 93 and Gemmeza 9, respectively, in the presence of NPK100% with a percentage increases of 41 and 29 more than un-inoculated plants. Results clearly indicated that, proline and Salicylic acid content were significantly increased in dual inoculated plants in Sakha 93 comparing to Gemmeza 9 under soil salinity up to 8 dSm -1 . The percentage increases were 38.6 and 37.54 for proline and 192.57 and 135.42 for salicylic acid in case of Sakha 93 and Gemmeza 9, respectively, in the presence of NPK75% and soil salinity 8-12 dSm -1 . No significant differences were observed among plants inoculated with G. intraradices and PGPR either in the presence of 75 or 100% of the recommended dose of NPK. Summing up it could be concluded that inoculation with AMF and Biotol successfully improve the growth, yield and salt stress tolerance of the tested cultivars in calcareous soil.

A greenhouse experiment was conducted to study the effect of two isolates of arbuscular mycorrhizal fungus (G3 and G4, Glomus intraradices) on the maize (Zea mays L.) growth, Na and some nutrients uptake in shoots, and roots content of salicylic acid, proline, arginine, phenylalanine and soluble sugar under Na Cl stress. Plants were subjected to four levels of salt stress (0.4, 2.0, 4.0 and 6.0 dSm-1), one week after germination. Mycorrhizal inoculation significantly reduced Na uptake in maize shoots. AMF treatments significantly increased salicylic acid content in roots (G3: 66.7 and 95.6%) and (G4: 17.4 and 50.4%) under 4.0 and 6.0 dSm-1 , respectively, more than the noninoculated ones at the end of the experiment. Proline and soluble sugar contents in roots showed pronounced increases. N and P uptake in AM shoots significantly increased under salt stress, as compared to the non-inoculated plants. Results conclusively indicate that mycorrhizal inoculation increased the salt stress tolerance of maize plants.

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