The Combined Use of Beneficial Soil Microorganisms Enhanced the Growth and Efficiently Reduced Lead Content in Leaves of Lettuce (Lactuca sativa L.) Plant under Lead Stress

Abstract

Two pots experiments were conducted, during two successive winter seasons of 2016/2017 and 2017/2018, to test the role of biofertilizer inoculations (arbuscular mycorrhizal fungi, AMF; Bacillus megaterium, B. megaterium; and their mixture) in improving growth and quality of lettuce (Lactuca sativa L. cv. Balady) under different levels (0, 100, 200 and 300 ppm) of lead (Pb). The results illustrated that the growth and quality of lettuce were greatly affected by the escalated levels of Pb in soil. Clearly, the increased levels of Pb decreased plant growth parameters, the contents of macronutrient and micronutrient as well as photosynthetic pigments, but increased the contents of Pb in the different parts of lettuce plants. Among the tested biofertilizer inoculations, the combined inoculation (AMF + B. megaterium) showed superior effects for increasing plant growth, contents of nutrient and photosynthetic pigments. AMF and the combined inoculation treatment exhibited an equal efficiency for reducing the content of Pb in the old and new leaves (edible parts) of lettuce plants, while B. megaterium showed the best performance in reducing the content of Pb in lettuce roots. Our study suggested that the combined inoculation (AMF + B. megaterium) is an effective tool for improving growth and quality of lettuce in high-contaminated soil with Pb.

Variation in Cadmium Accumulation among Potato Cultivars Grown on Different Agricultural Sites: A Potential Tool for Reducing Cadmium in Tubers

“…Liu et al [28] and Al Mamun et al [6] showed that plants accumulated less Cd in alkaline soils than acidic soils. The pH of Egyptian soil is generally in the alkaline range (7.7-8.3) [27,29,30]. Accordingly, the pH of the tested field sites ranged between 8.1 and 8.27 in both seasons, without significant differences between the four sites (Table 1).…”

The combined effects of gibberellic acid and kinetin on growth, yield and quality in globe artichoke (Cynara scolymus L.)

“…The relative chlorophyll contents of globe artichoke leaves were measured using the SPAD-502 chlorophyll meter device (Konica Minolta Sensing, Japan) (Brengi and Abouelsaad, 2019;Hassan and Ali, 2019) . Methods previously published by Page et al (1982) , John (1970) , andCottenie et al (1982) were used to measure nitrogen (N), phosphorous (P), and potassium (K) contents (% D.W.), respectively, in heads and leaves from each treatment.…”

Zinc oxide nanoparticles improve lettuce (Lactuca sativa L.) plant tolerance to cadmium by stimulating antioxidant defense, enhancing lignin content and reducing the metal accumulation and translocation

“…This eases the uptake of Cd by the roots to take up and send Cd to the leaves through the xylem ( Saidi et al., 2014 ). Trace concentrations of Cd can induce metal toxicity symptoms in plants ( Sary Hassan and Ibrahim Ali, 2019 ). Cadmium complicates the absorption of essential nutrients by plants and accumulates considerably disease in plants ( Usman et al., 2019 ).…”