Induced Resistance in Tomato Plants against Verticillium Wilt by the Binuclear Nickel Coordination Complex of the Ligand 2,5-Bis(pyridin-2-yl)-1,3,4-thiadiazole

• Published in: Journal of agricultural and food chemistry Vol. 64; no. 13; pp. 2661 - 2667
• Main Authors: Zine, Hanane, Rifai, Lalla Aicha, Faize, Mohamed, Bentiss, Fouad, Guesmi, Salaheddine, Laachir, Abdelhakim, Smaili, Amal, Makroum, Kacem, Sahibed-Dine, Abdelaziz, Koussa, Tayeb
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.04.2016
• Subjects: Arabidopsis - genetics; Disease Resistance; Gene Expression Regulation, Plant; Hypocreales - metabolism; Ligands; Lycopersicon esculentum - metabolism; Mitosporic Fungi; Nickel - pharmacology; Plant Diseases; Plant Proteins - metabolism; Plants, Genetically Modified - metabolism; Pyridines - chemistry; Pyridines - pharmacology; Thiadiazoles - chemistry; Thiadiazoles - pharmacology; Verticillium - pathogenicity; 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole; metal transition; protection; tomato; plant defenses; Verticillium
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.6b00151

Verticillium wilt caused by Verticillium dahliae is a major limiting factor for tomato production. The objective of this study was to evaluate the effectiveness of ligand 2,5-bis­(pyridin-2-yl)-1,3,4-thiadiazole (L) and its complex bis­[μ-2,5-bis­(pyridin-2-yl)-1,3,4-thiadiazole-κ4 N 2,N 3:N 4,N 5]­bis­[dihydrato-κO)­nickel­(II)] as activators of plant defenses in controlling Verticillium wilt. In the greenhouse, they protected tomato plants against V. dahliae when they were applied twice as foliar sprays at 100 μg mL–1. A synergistic effect was observed between the ligand L and the transition metal Ni, with disease incidence reduced by 38% with L and 57% with Ni2L2. Verticillium wilt foliar symptoms and vascular browning index were reduced by 82% for L and 95% for Ni2L2. This protection ability was associated with the induction of an oxidative burst and the activation of the total phenolic content as well as potentiation of the activity of peroxidase and polyphenol oxidase. These results demonstrated that L and Ni2L2 can be considered as new activators of plant defense responses.