Iron in the Symbiosis of Plants and Microorganisms

Abstract

Iron is an essential element for most organisms. Both plants and microorganisms have developed different mechanisms for iron uptake, transport and storage. In the symbiosis systems, such as rhizobia–legume symbiosis and arbuscular mycorrhizal (AM) symbiosis, maintaining iron homeostasis to meet the requirements for the interaction between the host plants and the symbiotic microbes is a new challenge. This intriguing topic has drawn the attention of many botanists and microbiologists, and many discoveries have been achieved so far. In this review, we discuss the current progress on iron uptake and transport in the nodules and iron homeostasis in rhizobia–legume symbiosis. The discoveries with regard to iron uptake in AM fungi, iron uptake regulation in AM plants and interactions between iron and other nutrient elements during AM symbiosis are also summarized. At the end of this review, we propose prospects for future studies in this fascinating research area.

Exploring the Roles of Arbuscular Mycorrhizal Fungi in Plant–Iron Homeostasis

“…AMF do not thrive specifically in the presence of iron, but iron availability in soil plays a crucial role in the interaction between AMF and plants. Iron deficiency may reduce arbuscule formation and function, hindering the symbiotic relationship and overall nutrient uptake for both the fungi and host plant [20]. Moreover, iron is essential for the growth and development of fungal hyphae, promoting them to form robust hyphal networks and facilitating root colonization [2].…”

“…Kabir et al [40] also found that AMF upregulate another ferric reductase gene, HaFRO1, alongside the expression of transport genes HaNramp1 and HaIRT1. Moreover, in the context of iron homeostasis, natural resistance-associated macrophage protein transporters also play a key role, and members, such as RiSMF1, RiSMF2, RiSMF3.1, and RiSMF3.2, have been identified in R. irregularis [20,44].…”

“…Interestingly, Złoch et al [71] noted that some plants can signal bacteria to produce more siderophores when experiencing iron deficiency. A comprehensive review by Liu et al [20] highlighted the complex interplay between bacteria, fungi, and plants in the process of iron acquisition, shedding light on the potential for harnessing these interactions in sustainable agriculture. Chelation of iron by soil bacteria and its transfer via hyphae to plants are integral components of soil-plant-microbe interactions.…”

AraMultiOmics: a tool for generating multi-omics features for downstream statistical analysis to infer the molecular basis of symbiosis among non-host plant Arabidopsis thaliana, host plant, and arbuscular mycorrhizal fungi

“…For instance, properties of AM-derived molecules may be inferred from comparative analyses among host-plants and non-host plants. For example, this involves examining changes in PNI and protein-protein interaction (PPI) due to increased accessibility of transition metals and to availability of new signaling molecules with complex structures, analyzing the gene expression of enzymes involved in cell wall and lipid metabolism, and assessing membrane thickness/ tilt angles of membrane proteins engaged in transporting AM-derived molecules [10][11][12][13]. We developed the AraMultiOmics, a toolkit for studying chromatin-related epigenetic regulation, TF binding profiles, DDI, protein-ligand profiling from protein structure alignment, metabolic pathway analysis, omics-association study, and DNA structure/protein metal binding potential in comparison with M. truncatula.…”

“…For instance, properties of AM-derived molecules may be inferred from comparative analyses among host-plants and non-host plants. For example, this involves examining changes in PNI and protein-protein interaction (PPI) due to increased accessibility of transition metals and to availability of new signaling molecules with complex structures, analyzing glycosylation/glycan structure and the gene expression of enzymes involved in cell wall and lipid metabolism, and assessing membrane lipid composition/thickness/ tilt angles of membrane proteins engaged in transporting AM-derived molecules [10][11][12][13]. We developed the AraMultiOmics that consisted of 10 modules where each module contains features derived from existing databases and software: 1) protein binding sites/open chromatin regions identified from chip-seq and their derivatives (ChIP-Hub, JASPAR, PCSD (Plant Chromatin State Database)), 2) DNA structure and metal binding profile (cran R gquad package (v2.1-2), QGRS program, and mebipred program), 3) DNA-TF binding profiles (TF-COMB (TF Co-Occurrence using Market Basket analysis.…”