title: Dissection of Trichoderma longibrachiatum-induced defense in onion (Allium cepa L.) against Fusarium oxysporum f. sp. cepa by target metabolite profiling.
abstract: Trichoderma spp. are versatile opportunistic plant symbionts that can cause substantial changes in the metabolism of host plants, thereby increasing plant growth and activating plant defense to various diseases. Target metabolite profiling approach was selected to demonstrate that Trichoderma longibrachiatum isolated from desert soil can confer beneficial agronomic traits to onion and induce defense mechanism against Fusarium oxysporum f. sp. cepa (FOC), through triggering a number of primary and secondary metabolite pathways. Onion seeds primed with Trichoderma T1 strain displayed early seedling emergence and enhanced growth compared with Trichoderma T2-treatment and untreated control. Therefore, T1 was selected for further investigations under greenhouse conditions, which revealed remarkable improvement in the onion bulb growth parameters and resistance against FOC. The metabolite platform of T1-primed onion (T1) and T1-primed onion challenged with FOC (T1+FOC) displayed significant accumulation of 25 abiotic and biotic stress-responsive metabolites, representing carbohydrate, phenylpropanoid and sulfur assimilation metabolic pathways. In addition, T1- and T1+FOC-treated onion plants showed discrete antioxidant capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) compared with control. Our findings demonstrated the contribution of T. longibrachiatum to the accumulation of key metabolites, which subsequently leads to the improvement of onion growth, as well as its resistance to oxidative stress and FOC.
authors.affiliation: The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553, Japan; Botany Department Faculty of Science, Aswan University, Aswan 81528, Egypt.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Abdelrahman
authors.affiliation: Botany Department Faculty of Science, Aswan University, Aswan 81528, Egypt.
authors.forename: Fatma
authors.initials: F
authors.lastname: Abdel-Motaal
authors.affiliation: Botany Department Faculty of Science, Aswan University, Aswan 81528, Egypt.
authors.forename: Magdi
authors.initials: M
authors.lastname: El-Sayed
authors.affiliation: Plant Healthcare and Diagnostic Center, PG Department of Biotechnology and Microbiology, Karnatak University, Dharwad 580 003, Karnataka, India.
authors.forename: Sudisha
authors.initials: S
authors.lastname: Jogaiah
authors.affiliation: The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Shigyo
authors.affiliation: Laboratory of Molecular Plant Pathology, Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan. Electronic address: shinsan@yamaguchi-u.ac.jp.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Ito
authors.affiliation: Plant Abiotic Stress Research Group & Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 70000, Vietnam; Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro-cho, Tsurumiku, Yokohama 230-0045, Japan. Electronic address: sontran@tdt.edu.vn.
authors.forename: Lam-Son Phan
authors.initials: LP
authors.lastname: Tran
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D016000:Cluster Analysis; D060467:Disease Resistance; D005670:Fusarium / Q000502:physiology*; D018525:Germination; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D008954:Models, Biological; D019697:Onions / Q000254:growth & development / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D012639:Seeds / Q000254:growth & development / Q000378:metabolism; D014242:Trichoderma / Q000502:physiology*
chemical_list: D000975:Antioxidants
keywords: Antioxidant; Metabolite profiling; Onion; Plant growth promoting fungi; Secondary metabolites