Chitosan Induces Plant Hormones and Defenses in Tomato Root Exudates

Marta Suarez-Fernandez; Frutos Carlos Marhuenda-Egea; Federico Lopez-Moya; Marino B Arnao; Francisca Cabrera-Escribano; Maria Jose Nueda; Benet Gunsé; Luis Vicente Lopez-Llorca

doi:10.3389/fpls.2020.572087

Chitosan Induces Plant Hormones and Defenses in Tomato Root Exudates

Front Plant Sci. 2020 Nov 4:11:572087. doi: 10.3389/fpls.2020.572087. eCollection 2020.

Authors

Marta Suarez-Fernandez^{1

2}, Frutos Carlos Marhuenda-Egea³, Federico Lopez-Moya², Marino B Arnao⁴, Francisca Cabrera-Escribano⁵, Maria Jose Nueda⁶, Benet Gunsé⁷, Luis Vicente Lopez-Llorca^{1

2}

Affiliations

¹ Laboratory of Plant Pathology, Multidisciplinary Institute for Environmental Studies Ramon Margalef, University of Alicante, Alicante, Spain.
² Department of Marine Sciences and Applied Biology, Laboratory of Plant Pathology, University of Alicante, Alicante, Spain.
³ Department of Agrochemistry and Biochemistry, Multidisciplinary Institute for Environmental Studies Ramon Margalef, University of Alicante, Alicante, Spain.
⁴ Department of Plant Biology (Plant Physiology), University of Murcia, Murcia, Spain.
⁵ Department of Organic Chemistry, Chemistry Faculty, University of Seville, Seville, Spain.
⁶ Department of Mathematics, University of Alicante, Alicante, Spain.
⁷ Plant Physiology Laboratory, Faculty of Biosciences, Universidad Autonoma de Barcelona, Bellaterra, Spain.

Abstract

In this work, we use electrophysiological and metabolomic tools to determine the role of chitosan as plant defense elicitor in soil for preventing or manage root pests and diseases sustainably. Root exudates include a wide variety of molecules that plants and root microbiota use to communicate in the rhizosphere. Tomato plants were treated with chitosan. Root exudates from tomato plants were analyzed at 3, 10, 20, and 30 days after planting (dap). We found, using high performance liquid chromatography (HPLC) and excitation emission matrix (EEM) fluorescence, that chitosan induces plant hormones, lipid signaling and defense compounds in tomato root exudates, including phenolics. High doses of chitosan induce membrane depolarization and affect membrane integrity. ¹H-NMR showed the dynamic of exudation, detecting the largest number of signals in 20 dap root exudates. Root exudates from plants irrigated with chitosan inhibit ca. twofold growth kinetics of the tomato root parasitic fungus Fusarium oxysporum f. sp. radicis-lycopersici. and reduced ca. 1.5-fold egg hatching of the root-knot nematode Meloidogyne javanica.

Keywords: chitosan; lipid signaling; membrane potential; plant defenses; plant hormones; root exudates; soil-borne pathogens.