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

Abstract

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-κ(4)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.

Functional Analogues of Salicylic Acid and Their Use in Crop Protection

“…maculicola, leptosphaera maculans (Laboratory) [84] Japanese pear/Venturia nashicola (Laboratory) [85] Cowpea/Colletotrichum destructivum (Laboratory) [86] Tobacco/TMV, CMV, Tomato spotted wilt virus (Laboratory) [87,88] Cucumber/Colletotrichum orbiculare, CMV (Laboratory) [85,89] Tomato/Clavibacter michighanensis subs. Tomato/Verticillium dahliae (Laboratory) [96] bis(azido-κN)bis(2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,…”

“…Despite of its direct antifungal activity, it is able to dramatically enhance the activity of several enzymes that are involved in plants defenses, such as peroxidase (POX), polyphenol oxidase (PPO), phenyl alanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), and catechol-ORice/Magnoporthe grisea (Field) [80] Tobacco/Tobacco mosaic virus, Pseudomonas syringae pv. tabaci, Erysiphae cichoracearum (Laboratory) [66,94] Tea/Colletotrichum theaasinensis, Pestalotiopsis longista (Field) [95] 2,5-bis (pyridi-2-yl)-1,3,4-thiadiazol Tomato/Verticillium dahliae (Laboratory) [96] bis(azido-κN)bis(2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,…”

“…It provides an excellent blast control lasting for more than two months. Despite of its direct antifungal activity, it is able to dramatically enhance the activity of several enzymes that are involved in plants defenses, such as peroxidase (POX), polyphenol oxidase (PPO), phenyl alanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), and catechol-OTomato/Verticillium dahliae (Laboratory) [96] Bis(µ-2,5-bis(pyridin-2-yl)-1,3,4-thiadiazoleκ4N2,N3:N4,N5)bis (dihydrato-κO)nickel(II)) (NiL 2 ) Tomato/Verticillium dahliae (Laboratory) [96] bis(azido-κN)bis(2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,…”

“…michiganensis, Verticillium dahliae (Laboratory/Field) [90,91] Oil seed rape/Leptosphaeria maculans (Laboratory/Field) [92] 2,2-2trifluoroethylbenzo( Tomato/Verticillium dahliae (Laboratory) [96] bis(azido-κN)bis(2,5-bis(pyridin-…”

2-[5-(Pyridin-2-yl)-1,3,4-thiadiazol-2-yl]pyridin-1-ium perchlorate

“…Transition metal complexes with the ligand 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole (L) have attracted considerable attention owing to their magnetic properties (Klingele et al, 2010) and biological activity (Zine et al, 2016). Indeed, the ligand (L) can coordinate to different metal ions in many modes (Bentiss et al, 2002(Bentiss et al, , 2011Ahmed et al, 2015;Laachir et al, 2013Laachir et al, , 2015a.…”