2,4-dichlorophenoxyacetic acid-induced leaf senescence in mung bean (Vigna radiata L. Wilczek) and senescence inhibition by co-treatment with silver nanoparticles

Effect of nanosilver in wheat seedlings and Fusarium culmorum culture systems

“…This may be explained by allocation of products of photosynthesis towards defensive reactions than growth. Application of AgNPs was accompanied by reactive oxygen species (ROS) generation that depended on kind, size and concentration of AgNPs (Karuppanapandian et al 2011;Panda et al 2011;Banerjee et al 2014). ROS as strong oxidizing agents may cause oxidative damage to lipids which affected membrane integrity and elevated electrolyte leakage (Anjum et al 2013).…”

“…According to Chai and Doke (1987) CAT and SOD activation is important in O 2 .-and H 2 O 2 scavenging and induction of systemic resistance to Phytophthora infestans. The reduction of CAT activity was explained by Karuppanapandian et al (2011) by the enzyme sensitivity to H 2 O 2 radicals. In turn, suppression of SOD activity could be associated with damage to proteins (Pillai et al 2014).…”

Insights into the toxicity mechanism of and cell response to the herbicide 2,4-D in plants

“…7 An overdose of 2,4-D exerts a pro-oxidant effect, inducing harmful ROS concentrations, and a failure in the detoxifying cell mechanisms, causing oxidative damage, nuclear-DNA fragmentation, and cell death. 8 The increase of ROS production induced by 2,4-D is a direct consequence of the activation of specific enzymes such as xanthine oxidoreductase (XOD) involved in ureide metabolism, acyl-CoA oxidase (ACX) involved in fatty acid β-oxidation and jasmonic acid biosynthesis, and lipoxygenase (LOX). 9 NADPH oxidases from the plasma membrane have been considered one of the main sources of ROS induced by auxinic compounds, although in pea plants this activity has been found not to change in response to 2,4-D. 9 ROS are also involved in 2,4-D-induced epinasty by promoting cell expansion and vasculartissue proliferation, 9,10 also acting as signal molecules to induce the cellular response against stress conditions.…”

“…13 However, the role of ET on 2,4-D toxicity is controversial and several authors have demonstrated that it does not participate in 2,4-D-dependent leaf epinasty, 9,14,15 although it can participate in the 2,4-Dinduced plant senescence. 8,9 Another consequence of ET overproduction is the formation of cyanide, an inhibitor of plant enzymes and proteins such as cytochrome-c oxidase, RuBisCo, nitrate/ nitrite reductase, catalase, and peroxidase. 13 As a response to the ET burst, the biosynthesis of abscisic acid (ABA) has been reported to be induced; through the overexpression of genes such as NCED1, which encodes a key regulatory enzyme of ABA biosynthesis.…”

Molecular Physiology of Heat Stress Responses in Plants

“…Singlet oxygen, which is formed during photoinhibition, and PSII electron transfer reactions, can directly oxidize DNA, proteins, and polyunsaturated fatty acids (Karuppanapandian et al 2011 ). Superoxide radicals are formed in many photooxidation reactions in chloroplasts, electron transport chain reactions in mitochondria, and other reactions in the plasma membrane (Halliwell 2006 ).…”