Thiamine-induced nitric oxide improves tolerance to boron toxicity in pepper plants by enhancing antioxidants

Authors : Cengiz KAYA, Mustafa ASLAN, Ferhat UĞURLAR, Muhammad ASHRAF

Pages : 379-390

View : 17 | Download : 8

Publication Date : 2020-08-01

Article Type : Research Paper

Abstract :The role of thiamine insert ignore into journalissuearticles values(THI);-induced nitric oxide insert ignore into journalissuearticles values(NO); synthesis in the improvement of tolerance to boron insert ignore into journalissuearticles values(B); toxicity in pepper insert ignore into journalissuearticles values(Capsicum annuum L.); was studied. A solution of THI insert ignore into journalissuearticles values(50 or 100 mg L-1); was sprayed to the foliage of pepper plants exposed to high B regime insert ignore into journalissuearticles values(2.0 mM H3BO3); once a week for 4 weeks. A scavenger of NO insert ignore into journalissuearticles values(0.1 mM);, cPTIO, along with THI was sprayed once a week to ascertain whether or not endogenous NO played a role in the alleviation of B stress in pepper plants by THI. There were significant reductions in plant dry weight, PSII quantum efficiency insert ignore into journalissuearticles values(F-v/F-m);, total chlorophyll, leaf calcium insert ignore into journalissuearticles values(Ca2+); and potassium insert ignore into journalissuearticles values(K+); contents as well as leaf water potential by 47.57%, 28.78%, 34.42%, 45.45%, 55.53%, and 471.4%, respectively, but there was a significant increase in the leaf proline, ascorbate insert ignore into journalissuearticles values(AsA);, glutathione insert ignore into journalissuearticles values(GSH);, hydrogen peroxide, malondialdehyde, electron leakage, B levels and NO by 2.6-, 2.3-, 1.9, 3.7-, 5.6-, 2.2-, 3.6-, and 3.0-fold, respectively in B-stressed plants. Both treatments of TI II mitigated B-induced oxidative damage and led to a further increase in NO synthesis. The positive effect of THI on plants grown under B stress was fully eliminated by the cPTIO application by lowering leaf NO content. These findings exhibit that NO may function as a downstream signal in THI-induced tolerance to B toxicity in pepper plants by reversing oxidative stress, enhancing the antioxidant defense mechanism and sustaining mineral nutrient homeostasis. Thus, NO and THI both contributed to improved B toxicity tolerance in pepper plants.
Keywords : Antioxidant system, boron toxicity, nitric oxide, pepper, thiamine