Open Access

ARTICLE

Alleviation of Cadmium Toxicity to Medicago Truncatula by AMF Involves the Changes of Cd Speciation in Rhizosphere Soil and Subcellular Distribution

Yuying Jiang^1,#, Renhua Huang^1,#, Lei Jiang¹, Ke Chen^1,*, Wenkun Zhu^2,*
1 School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China
2 State Key Laboratory of Environmentally Friendly Energy Materials, National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, School of National Defence, Sichuan Civil-Military Integration Institute, Southwest University of Science and Technology, Mianyang, 621010, China
* Corresponding Authors: Ke Chen. Email: ; Wenkun Zhu. Email:
# These authors contributed equally
(This article belongs to this Special Issue: Plant Physiology for Crop Production and Sustainable Agriculture)

Phyton-International Journal of Experimental Botany 2021, 90(2), 403-415. https://doi.org/10.32604/phyton.2021.014376

Received 22 September 2020; Accepted 27 October 2020; Issue published 07 February 2021

Abstract

Arbuscular mycorrhizal fungi (AMF) can improve plant tolerance to several abiotic stresses, including heavy metals, drought or salinity exposure. However, the role of AMF in alleviation of soil cadmium (Cd)-induced toxicity to plants is still largely unknown. In this study, Cd speciation in soil and subcellular distribution of Cd were used to characterize the roles of application AM fungi in the alleviation of Cd toxicity in alfalfa plants. Our results showed that the addition of Glomus mosseae in Cd contaminated soil (10 mg/Kg) significantly increased soil pH, cation exchange capacity (CEC) and organic matter in rhizosphere soil with Medicago truncatula L., and then account for significantly decreased contents of exchangeable and carbonate-bounded Cd speciation in rhizosphere soil, indicating alleviation of plant toxicity by reduction of bioavailable fractions of Cd. Although there is no significant difference found in Cd accumulation by roots and shoots respectively between Cd and AM-Cd treatments, more portion of Cd was recorded compartmentalization in cell wall fraction of both root and shoot in treatment of Cd with AM application, indicating alleviation of Cd toxicity to plant cell. Herein, application of AM fungi in Cd treatments performed to inhibit the appearance of Cd toxicity symptoms, including the improvement of leaf electrolyte leakage, root elongation, seedling growth and biomass. This information provides a clearer understanding of detoxification strategy of AM fungi on Cd behavior with development and stabilization of soil structure and subcellular distribution of plant.

---

Keywords

AM fungi; cadmium toxicity; Cd form; subcellular compartmentalization; phytoremediation

---

Citations