scholarly journals Klebsiella variicola improves the antioxidant ability of maize seedlings under saline-alkali stress

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11963
Author(s):  
Lijuan Yang ◽  
Yufeng Wang ◽  
Kejun Yang

Background Saline-alkali soil is mainly distributed in the northern and coastal areas of China. The Songnen Plain, located in the northeast of China, is a region with a relatively high concentration of saline-alkali soil and is also one of the more at-risk areas in the country. Every year, the increasing spread of saline-alkali soil areas has a serious impact on the growth of agricultural crops. The maize crop is sensitive to saline-alkali stress, which seriously affects its growth and development. Our previous study determined that Klebsiella variicola performs a variety of biological functions, as well as improves the rhizosphere microenvironment and promotes the growth and development of maize seedlings in saline-alkali soil environments. The present study further analyzed the mechanism that enables K. variicola to alleviate saline-alkali stress at the level of the antioxidant system. Methods The accumulation of O2− was observed directly via histochemical staining. The activities of several antioxidant enzymes were determined using the nitro blue tetrazolium and the guaiacol methods. The contents of non-enzymatic antioxidants were determined using the dithionitrobenzoic acid method. Results The contents of the superoxide anion and hydrogen peroxide in leaves and roots of maize seedlings increased under saline-alkali stress conditions. The higher level of reactive oxygen species increased the degree of membrane lipid peroxidation. There were differences in the degree of oxidative damage and performance of the antioxidant defence system in maize seedlings under saline-alkali stress. Following the application of increasing concentrations of K. variicola, the activity of antioxidant enzymes increased by 21.22%–215.46%, and the content of non-enzymatic antioxidants increased as well, the ratios of ASA/DHA and GSH/GSSG in leaves increased by 4.97% and 1.87 times, respectively, and those in roots increased by 3.24% and 1.60 times, respectively. The accumulation of reactive oxygen species was reduced, and the content of H2O2 decreased by 26.07%–46.97%. The content of O2− decreased by 20.18%–37.01%, which alleviated the oxidative damage to maize seedlings caused by saline-alkali stress. Conclusion K. variicola reduced ROS-induced peroxidation to membrane lipids and effectively alleviated the damage caused by saline-alkali stress by increasing the activities of antioxidant enzymes in maize seedlings, thus enhancing their saline-alkali tolerance. A bacterial concentration of 1×108 cfu/mL was optimal in each set of experiments.

2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Pallavi Sharma ◽  
Ambuj Bhushan Jha ◽  
Rama Shanker Dubey ◽  
Mohammad Pessarakli

Reactive oxygen species (ROS) are produced as a normal product of plant cellular metabolism. Various environmental stresses lead to excessive production of ROS causing progressive oxidative damage and ultimately cell death. Despite their destructive activity, they are well-described second messengers in a variety of cellular processes, including conferment of tolerance to various environmental stresses. Whether ROS would serve as signaling molecules or could cause oxidative damage to the tissues depends on the delicate equilibrium between ROS production, and their scavenging. Efficient scavenging of ROS produced during various environmental stresses requires the action of several nonenzymatic as well as enzymatic antioxidants present in the tissues. In this paper, we describe the generation, sites of production and role of ROS as messenger molecules as well as inducers of oxidative damage. Further, the antioxidative defense mechanisms operating in the cells for scavenging of ROS overproduced under various stressful conditions of the environment have been discussed in detail.


2020 ◽  
Vol 21 (5) ◽  
pp. 477-498
Author(s):  
Yongfeng Chen ◽  
Xingjing Luo ◽  
Zhenyou Zou ◽  
Yong Liang

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients’ life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.


Author(s):  
Kanya Thongra-ar ◽  
Piyanuch Rojsanga ◽  
Savita Chewchinda ◽  
Supachoke Mangmool ◽  
Pongtip Sithisarn

The objects of this study were to determine the effects to reactive oxygen species and antioxidant enzymes levels in HEK-293 cells and inhibition of α-glucosidases and α-amylase enzymes of extracts from Persicaria odorata or phak phaeo. The ethanol extracts from the leaves and the stems of phak phaeo were investigated for their 2,2-diphenyl-1-picryhydrazyl (DPPH) scavenging activities (IC50 were 7.74 ± 0.47 and 7.91 ± 0.43 µg/mL, respectively). Cellular antioxidant effects in human embryonic kidney-293 (HEK-293) cells with these extracts (0.1 mg/mL) also increased the mRNA expressions of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx-1), catalase and glutathione reductase (GRe). The leaf extract showed the higher efficacies in the induction of the mRNA expressions of Mn-SOD, GPx-1 and GRe while the stem extract exhibited a stronger effect to the induction of catalase. Phak phaeo in vitro inhibitory effects to α-glucosidase enzyme (IC50 values of 9.82 ± 1.64 and 13.99 ± 1.45 µg/mL, respectively and also strong inhibition to α-amylase with IC50 values of 90.66 ± 8.75 and 19.96 ± 5.37 µg/mL, respectively). Lineweaver-Burk plot demonstrated that phak phaeo extracts inhibited α-glucosidase and α- amylase in non-competitive manners. Total phenolic and total flavonoid contents were determined by Folin-Ciocalteu and aluminium chloride methods (the leaf and stem extracts were 22.89 ± 9.16 and 22.27 ± 8.77 g gallic acid equivalent in 100 g extract (g% GAE) and 7.20 ± 3.61 and 4.06 ± 1.73 g quercetin equivalent in 100 g extract (g% QE), respectively). Keywords: Antioxidant enzymes, DPPH, HEK-293, MTT assay, Persicaria odorata, Reactive oxygen species, Total phenolic, Total flavonoid, α-glucosidases, α-amylase


Author(s):  
Minu Kesheri ◽  
Swarna Kanchan ◽  
Rajeshwar P. Sinha

In retrospect to the rise in the occurrence of ageing related disorders and the everlasting desire to overcome ageing, exploring the causes, mechanisms and therapies to curb ageing becomes relevant. Reactive Oxygen Species (ROS) are commonly generated during normal growth and development. However abiotic and biotic stresses enhance the level of ROS which in turn pose the threat of oxidative stress. Ability to perceive ROS and to speedily commence antioxidant defenses is crucial for the survival as well as longevity of living cells. Therefore living organisms are bestowed with antioxidants to combat the damages caused by oxidative stress. This chapter aims to elucidate an overview of the process of ageing, generation and enhancement of reactive oxygen species, damages incurred by oxidative stress, its amelioration strategies, therapeutic and biotechnological potentials of antioxidants and various sources of bioactive compounds significant in retardation of aging process.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 428 ◽  
Author(s):  
Sayed Mohsin ◽  
Mirza Hasanuzzaman ◽  
M. Bhuyan ◽  
Khursheda Parvin ◽  
Masayuki Fujita

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses of fungicides (1.375 µM TEB + 0.5 µM TRI and 2.75 µM TEB + 1.0 µM TRI) solely and in combination with NaCl (60 mM) for six days. The application of salt phenotypically deteriorated the cucumber plant growth that caused yellowing of the whole plant and significantly destructed the contents of chlorophyll and carotenoids. The oxidative damage was created under salinity by increasing the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolytic leakage (EL) resulting in the disruption of the antioxidant defense system. Furthermore, in the leaves, stems, and roots of cucumber plants increased Na+ content was observed under salt stress, whereas the K+/Na+ ratio and contents of K+, Ca2+, and Mg2+ decreased. In contrast, the exogenous application of TEB and TRI reduced the contents of MDA, H2O2, and EL by improving the activities of enzymatic and non-enzymatic antioxidants. In addition, ion homeostasis was regulated by reducing Na+ uptake and enhanced K+ accumulation and the K+/Na+ ratio after application of TEB and TRI. Therefore, this study indicates that the exogenous application of TEB and TRI enhanced salt tolerance in cucumber plants by regulating reactive oxygen species production and antioxidant defense systems.


Sign in / Sign up

Export Citation Format

Share Document