Omics approaches revealed how arbuscular mycorrhizal symbiosis enhances yield and resistance to leaf pathogen in wheat

Abstract

Besides improved mineral nutrition, plants colonised by arbuscular mycorrhizal (AM) fungi often display increased biomass and higher tolerance to biotic and abiotic stresses. Notwithstanding the global importance of wheat as an agricultural crop, its response to AM symbiosis has been poorly investigated. We focused on the role of an AM fungus on mineral nutrition of wheat, and on its potential protective effect against Xanthomonas translucens. To address these issues, phenotypical, molecular and metabolomic approaches were combined. Morphological observations highlighted that AM wheat plants displayed an increased biomass and grain yield, as well as a reduction in lesion area following pathogen infection. To elucidate the molecular mechanisms underlying the mycorrhizal phenotype, we investigated changes of transcripts and proteins in roots and leaves during the double (wheat-AM fungus) and tripartite (wheat-AM fungus-pathogen) interaction. Transcriptomic and proteomic profiling identified the main pathways involved in enhancing plant biomass, mineral nutrition and in promoting the bio-protective effect against the leaf pathogen. Mineral and amino acid contents in roots, leaves and seeds, and protein oxidation profiles in leaves, supported the omics data, providing new insight into the mechanisms exerted by AM symbiosis to confer stronger productivity and enhanced resistance to X. translucens in wheat.

Systems Biology of Plant-Microbiome Interactions

“…In a remarkable study combining multi-omics approaches, the effects of beneficial microbes toward increased biomass and higher tolerance to biotic and abiotic stresses in monocot crops was investigated. Fiorilli et al (2018) studied the three-way interactions between the wheat pathogen Xanthomonas translucens, the protective symbiotic AM fungus, and the host using phenotyping, transcriptomic, molecular, and metabolomic approaches. They proposed a two-step process for conferring Xanthomonas resistance to AM-treated wheat: first, the activation of a broad-spectrum defense (BSD) response that takes place in roots and leaves of AM-treated plants, and second, a switch to pathogen-specific defense (PSD) upon bacterial infection, which ultimately leads to protection against the pathogen.…”

In silico analysis of fungal small RNA accumulation reveals putative plant mRNA targets in the symbiosis between an arbuscular mycorrhizal fungus and its host plant

“…Such an intimate colonization of plant tissues relies on an efficient molecular communication system, which occurs before the contact, and on extensive structural and metabolic rearrangements on both plant and fungal sides, which have been only partially described [2, 4]. Transcriptomic studies, mainly focused on plant protein-encoding genes, have been instrumental to describe the molecular reprogramming that the AMF colonization induces in different host plants not only locally (roots; [5–7]) but also systemically (shoot and fruit; [8, 9]) level. Nevertheless, investigations on transcript profiles have been performed to a lower extent also on the AMF [10].…”

VAPYRIN attenuates defence by repressing PR gene induction and localized lignin accumulation during arbuscular mycorrhizal symbiosis ofPetunia hybrida

“…phosphate and ammonium transporters), many AM-induced genes are related to established defense genes (e.g. PR genes) (Gao et al, 2004;Grunwald et al, 2004;Deguchi et al, 2007;Liu et al, 2007;Siciliano et al, 2007;Fiorilli et al, 2009;Breuillin et al, 2010;Campos-Soriano et al, 2010;Gaude et al, 2012;Handa et al, 2015;Fiorilli et al, 2018). In addition, we know that the complex signaling mechanism in symbiosis includes, besides dedicated symbiosis signals (myc factors) molecular species that are known to also play a role in disease resistance, e.g.…”