Funneliformis mosseae Enhances Root Development and Pb Phytostabilization in Robinia pseudoacacia in Pb-Contaminated Soil

Abstract

It is possible that arbuscular mycorrhizal fungi play a pivotal role in root development and Pb phytostabilization in plants grown in Pb-contaminated soil. In this study, a pot experiment was conducted over 4 months to evaluate the effects of Funneliformis mosseae strain BGCXJ01A on root characteristics of black locust (Robinia pseudoacacia L.) seedlings in Pb-contaminated soil. Four Pb treatments (0, 90, 900, and 3,000 mg kg–1) were applied to soil in the presence and absence of F. mosseae. Inoculation with F. mosseae prominently improved root length, surface area, volume, and tip number in the plants across all Pb treatments. The F. mosseae inoculation also increased root diameter and fork number, especially under high Pb treatments. The presence of F. mosseae significantly increased the root activity and root tolerance index. However, there was little difference in specific root length between inoculated and non-inoculated plants. The biomass of roots, stems, and leaves all increased following inoculation with F. mosseae. Inoculated plants had greater accumulation and translocation capacities for Pb in the roots and stems, but lower capacities were found in the leaves when compared with those in non-inoculated plants. These results highlight that F. mosseae can alleviate the toxic effects of Pb on root development and can immobilize Pb in the roots and stems of R. pseudoacacia grown in Pb-contaminated soil. This study provides a model system for phytoremediation of Pb-contaminated soil via reciprocal symbiosis between arbuscular mycorrhizal fungi and woody legumes.

Rhizoglomus intraradices Improves Plant Growth, Root Morphology and Phytohormone Balance of Robinia pseudoacacia in Arsenic-Contaminated Soils

“…This study showed that the root diameter, total root length, root surface area, root volume, and the number of root forks and tips of the R. intraradices-inoculated seedlings were higher than those of the non-inoculated seedlings under the same levels of As stress. Our results were similar to the conclusion by Huang et al (2019) and Wu et al (2011). The root lengths of G. mosseae-inoculated Z. mays were up to 3.4 times those of the non-inoculated controls in As-contaminated soils, and the enlarged root systems of the host plants also contributed primarily to nutrient acquisition with G. mosseae inoculation (Xia et al, 2007).…”

“…In the current study, the total root length, root surface area, root volume, and the number of root forks and tips of R. pseudoacacia seedlings were decreased with the increase of As concentration in soils. Huang et al (2019) also found that the Pb toxicity in soils decreased the root length, root diameter, and root surface area of R. pseudoacacia seedlings. Spagnoletti and Lavado (2015) verified that the morphological traits of G. max seedlings, like root length, were negatively influenced by the As concentration in soils.…”

“…The parameters of root morphological characteristics, which included the root length, root surface area, root volume, and the number of root forks and tips, were also closely related to the adaptation, health status, and productivity of plants. The good morphological parameters indicated that the root system was more suitable for absorbing water and nutrients from soils (Huang et al, 2019). As a sensitive system of plants for perceiving the soil environment, the root tissue showed astonishing morphological changes to minimize the physiological metabolism and maximize the nutrient acquisition (Mishra et al, 2017).…”

“…Hence, it is probably deemed as an ideal candidate of dominant pioneer trees for vegetation recovery in As-contaminated areas ( Rajkumar et al, 2012 ). Moreover, R. pseudoacacia can establish an intimate symbiotic relationship with AMF in HM-contaminated soils ( Huang et al, 2019 ). Recent studies have shown that AMF Funneliformis mosseae alleviates the effects of lead (Pb) toxicity by improving the plant biomass, root activity, antioxidant enzymes, and photosynthesis in R. pseudoacacia seedlings grown in Pb-contaminated soils ( Yang et al, 2015 ; Huang et al, 2019 ).…”

Nitrate Transporter Gene Expression and Kinetics of Nitrate Uptake by Populus × canadensis ‘Neva’ in Relation to Arbuscular Mycorrhizal Fungi and Nitrogen Availability

“…The establishment of AM in roots can trigger the changes in root activities and gene expression patterns of root systems, for example, in grapevine (Balestrini et al, 2017;Torres et al, 2018), Robinia pseudoacacia (Huang et al, 2019), L. japonicus (Guether et al, 2009), and Lycopersicon esculentum (Hildebrandt et al, 2002). The results of this study showed that the active absorbing area/total absorbing area ratios of AM plants were higher than those in NM plants, which was in keeping with observations by Liu et al (2014) and Huang et al (2019). An increase in root activities suggests a stronger element uptake capacity (Yang et al, 2008).…”