Exogenous spermidine improves drought tolerance in maize by enhancing the antioxidant defence system and regulating endogenous polyamine metabolism

2018 ◽  
Vol 69 (11) ◽  
pp. 1076 ◽  
Author(s):  
Lijie Li ◽  
Wanrong Gu ◽  
Congfeng Li ◽  
Wenhua Li ◽  
Caifeng Li ◽  
...  
Keyword(s):  
Drought Stress ◽  
Crop Production ◽  
Arginine Decarboxylase ◽  
Polyamine Metabolism ◽  
Monodehydroascorbate Reductase ◽  
Antioxidant Defence ◽  
Defence System ◽  
Maize Cultivars ◽  
Antioxidant Defence System ◽  
Exogenous Spermidine

Drought stress is a primary abiotic constraint affecting crop production worldwide. In this study, the role of exogenous spermidine (Spd) in conferring drought-stress-tolerance in maize (Zea mays L.) seedlings was studied by analysing polyamine metabolism and the antioxidant defence system. Two maize cultivars, Xianyu 335 (drought resistant) and Fenghe 1 (drought susceptible), were subjected to drought stress (–0.8 MPa) induced by 15% polyethylene glycol 6000 with or without Spd (0.1 mm) application. Spd significantly reduced the inhibition of plant growth and decreased malondialdehyde and hydrogen peroxide contents and the generation rate of oxidised glutathione caused by drought stress, particularly in Fenghe 1. The activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase further increased with the application of Spd to the stressed plants. Application of Spd significantly moderated the drought-induced reduction in activities of monodehydroascorbate reductase and dehydroascorbate and the ratio ascorbate : dehydroascorbate and reduced the ratio glutathione : oxidised glutathione. With the application of Spd, the contents of Spd and spermine and the activities of arginine decarboxylase, S-adenosyl methionine decarboxylase and diamine oxidase increased significantly in the stressed plants, and the increases were greater in Xianyu 335 than in Fenghe 1. Thus, exogenous Spd successfully reduced oxidative damage by enhancing the antioxidant components, raising the redox state of ascorbate and glutathione, and altering the polyamine pool, which play important roles in improving physiological characteristics and drought stress in maize.

scholarly journals Stage specific upregulation of antioxidant defence system in leaves for regulating drought tolerance in chickpea

2014 ◽  
Vol 6 (2) ◽  
pp. 326-337 ◽  
Author(s):  
H. K. Oberoi ◽  
A. K. Gupta ◽  
S. Kaur ◽  
I. Singh
Keyword(s):  
Hydrogen Peroxide ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Vegetative Stage ◽  
Antioxidant Defence ◽  
Seed Filling ◽  
Defence System ◽  
Antioxidant Defence System ◽  
Young Leaves ◽  
The Impact

Leaf is one of the early sensors for the drought stress and is important to study drought tolerance mechanism. Activities of antioxidative enzymes and status of malondialdehyde (MDA), hydrogen peroxide (H2O2), proline and total phenols were studied in leaves of drought tolerant (PDG 3 and PDG 4) and susceptible (PBG 1, GPF 2, PBG 5, L 550 and BG1053) chickpea cultivars under irrigated and rainfed conditions at different development stages. In general, with the age of plant, the activities of superoxide dismutase (SOD) and catalase (CAT) increased but the activities of glutathione reductase (GR), ascorbate peroxidase (APX) and peroxidase (POX) decreased in leaves. With some exceptions, in general, higher status of APX and POX in leaves at vegetative stage I (30 days after sowing) and II (60 days after sowing); GR at vegetative stage II and pre-flowering stage and SOD and CAT at seed filling stages in tolerant cultivars under drought stress reflected stage specific upregulation of antioxidant defence system in them. The relatively lower activities of APX and POX in old leaves during seed filling stage make them more prone to enhanced oxidative injury than the young leaves. Lower content of hydrogen peroxide and malondialdehyde in leaves of tolerant cultivars during seed filling reflects the impact of antioxidant defence system operative at that time. The higher accumulation of proline and total phenol in leaves of tolerant cultivars might be playing important role in drought stress tolerance. These results indicated the importance of upregulation of different antioxidant enzymes at variable stages of leaf development.

scholarly journals Recent Developments in Enzymatic Antioxidant Defence Mechanism in Plants with Special Reference to Abiotic Stress

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 267 ◽  
Author(s):  
Vishnu D. Rajput ◽  
Harish ◽  
Rupesh Kumar Singh ◽  
Krishan K. Verma ◽  
Lav Sharma ◽  
...  
Keyword(s):  
Monodehydroascorbate Reductase ◽  
Oxygen Species ◽  
Antioxidant Defence ◽  
Defence System ◽  
Antioxidant Defence System ◽  
Plant Enzymes ◽  
Recent Developments ◽  
Health And Development ◽  
Glutathione S Transferases

The stationary life of plants has led to the evolution of a complex gridded antioxidant defence system constituting numerous enzymatic components, playing a crucial role in overcoming various stress conditions. Mainly, these plant enzymes are superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferases (GST), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR), which work as part of the antioxidant defence system. These enzymes together form a complex set of mechanisms to minimise, buffer, and scavenge the reactive oxygen species (ROS) efficiently. The present review is aimed at articulating the current understanding of each of these enzymatic components, with special attention on the role of each enzyme in response to the various environmental, especially abiotic stresses, their molecular characterisation, and reaction mechanisms. The role of the enzymatic defence system for plant health and development, their significance, and cross-talk mechanisms are discussed in detail. Additionally, the application of antioxidant enzymes in developing stress-tolerant transgenic plants are also discussed.

scholarly journals Downregulation of FeSOD-A expression in Leishmania infantum alters trivalent antimony and miltefosine susceptibility

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ana Maria Murta Santi ◽  
Paula Alves Silva ◽  
Isabella Fernandes Martins Santos ◽  
Silvane Maria Fonseca Murta
Keyword(s):  
Oxidative Stress ◽  
Western Blot ◽  
Leishmania Infantum ◽  
Transcript Level ◽  
Drug Susceptibility ◽  
Central Component ◽  
Multiplication Rate ◽  
Antioxidant Defence ◽  
Defence System ◽  
Antioxidant Defence System

Abstract Background Superoxide dismutase (SOD), a central component of the antioxidant defence system of most organisms, removes excess superoxide anions by converting them to oxygen and hydrogen peroxide. As iron (Fe) SOD is absent in the human host, this enzyme is a promising molecular target for drug development against trypanosomatids. Results We obtained Leishmania infantum mutant clones with lower FeSOD-A expression and investigated their phenotypes. Our attempts to delete this enzyme-coding gene using three different methodologies (conventional allelic replacement or two different CRISPR/methods) failed, as FeSOD-A gene copies were probably retained by aneuploidy or gene amplification. Promastigote forms of WT and mutant parasites were used in quantitative reverse-transcription polymerase chain reaction (RT-qPCR) and western blot analyses, and these parasite forms were also used to assess drug susceptibility. RT-qPCR and western blot analyses revealed that FeSOD-A transcript and protein levels were lower in FeSOD-A−/−/+L. infantum mutant clones than in the wild-type (WT) parasite. The decrease in FeSOD-A expression in L. infantum did not interfere with the parasite growth or susceptibility to amphotericin B. Surprisingly, FeSOD-A−/−/+L. infantum mutant clones were 1.5- to 2.0-fold more resistant to trivalent antimony and 2.4- to 2.7-fold more resistant to miltefosine. To investigate whether the decrease in FeSOD-A expression was compensated by other enzymes, the transcript levels of five FeSODs and six enzymes from the antioxidant defence system were assessed by RT-qPCR. The transcript level of the enzyme ascorbate peroxidase increased in both the FeSOD-A−/−/+ mutants tested. The FeSOD-A−/−/+ mutant parasites were 1.4- to 1.75-fold less tolerant to oxidative stress generated by menadione. Infection analysis using THP-1 macrophages showed that 72 h post-infection, the number of infected macrophages and their intracellular multiplication rate were lower in the FeSOD-A−/−/+ mutant clones than in the WT parasite. Conclusions The unsuccessful attempts to delete FeSOD-A suggest that this gene is essential in L. infantum. This enzyme plays an important role in the defence against oxidative stress and infectivity in THP-1 macrophages. FeSOD-A-deficient L. infantum parasites deregulate their metabolic pathways related to antimony and miltefosine resistance. Graphic Abstract

Sign in / Sign up

Export Citation Format

Share Document