scholarly journals Seed Treatment with Trichoderma longibrachiatum T6 Promotes Wheat Seedling Growth under NaCl Stress Through Activating the Enzymatic and Nonenzymatic Antioxidant Defense Systems

2019 ◽  
Vol 20 (15) ◽  
pp. 3729 ◽  
Author(s):  
Shuwu Zhang ◽  
Bingliang Xu ◽  
Yantai Gan

Salt stress is one of the major abiotic stresses limiting crop growth and productivity worldwide. Species of Trichoderma are widely recognized for their bio-control abilities, but little information is regarding to the ability and mechanisms of their promoting plant growth and enhancing plant tolerance to different levels of salt stress. Hence, we determined (i) the role of Trichoderma longibrachiatum T6 (TL-6) in promoting wheat (Triticum aestivum L.) seed germination and seedling growth under different levels of salt stress, and (ii) the mechanisms responsible for the enhanced tolerance of wheat to salt stress by TL-6. Wheat seeds treated with or without TL-6 were grown under different levels of salt stress in controlled environmental conditions. As such, the TL-6 treatments promoted seed germination and increased the shoot and root weights of wheat seedlings under both non-stress and salt-stress conditions. Wheat seedlings with TL-6 treatments under different levels of NaCl stress increased proline content by an average of 11%, ascorbate 15%, and glutathione 28%; and decreased the contents of malondialdehyde (MDA) by an average of 19% and hydrogen peroxide (H2O2) 13%. The TL-6 treatments induced the transcriptional level of reactive oxygen species (ROS) scavenging enzymes, leading to the increases of glutathione s-transferase (GST) by an average of 17%, glutathione peroxidase (GPX) 16%, ascorbate peroxidase (APX) 17%, glutathione reductase (GR) 18%, dehydroascorbate reductase (DHAR) 5%. Our results indicate that the beneficial strain of TL-6 effectively scavenged ROS under NaCl stress through modulating the activity of ROS scavenging enzymes, regulating the transcriptional levels of ROS scavenging enzyme gene expression, and enhancing the nonenzymatic antioxidants in wheat seedling in response to salt stress. Our present study provides a new insight into the mechanisms of TL-6 can activate the enzymatic and nonenzymatic antioxidant defense systems and enhance wheat seedling tolerance to different levels of salt stress at physiological, biochemical and molecular levels.

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2224
Author(s):  
Mira Rahman ◽  
Khussboo Rahman ◽  
Khadeja Sultana Sathi ◽  
Md. Mahabub Alam ◽  
Kamrun Nahar ◽  
...  

The present investigation was executed with an aim to evaluate the role of exogenous selenium (Se) and boron (B) in mitigating different levels of salt stress by enhancing the reactive oxygen species (ROS) scavenging, antioxidant defense and glyoxalase systems in soybean. Plants were treated with 0, 150, 300 and 450 mM NaCl at 20 days after sowing (DAS). Foliar application of Se (50 µM Na2SeO4) and B (1 mM H3BO3) was accomplished individually and in combined (Se+B) at three-day intervals, at 16, 20, 24 and 28 DAS under non-saline and saline conditions. Salt stress adversely affected the growth parameters. In salt-treated plants, proline content and oxidative stress indicators such as malondialdehyde (MDA) content and hydrogen peroxide (H2O2) content were increased with the increment of salt concentration but the relative water content decreased. Due to salt stress catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glyoxalase I (Gly I) and glyoxalase II (Gly II) activity decreased. However, the activity of ascorbate peroxidase (APX), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST) and peroxidase (POD) increased under salt stress. On the contrary, supplementation of Se, B and Se+B enhanced the activities of APX, MDHAR, DHAR, GR, CAT, GPX, GST, POD, Gly I and Gly II which consequently diminished the H2O2 content and MDA content under salt stress, and also improved the growth parameters. The results reflected that exogenous Se, B and Se+B enhanced the enzymatic activity of the antioxidant defense system as well as the glyoxalase systems under different levels of salt stress, ultimately alleviated the salt-induced oxidative stress, among them Se+B was more effective than a single treatment.


2010 ◽  
Vol 56 (No. 10) ◽  
pp. 470-475 ◽  
Author(s):  
Q.S. Wu ◽  
Y.N. Zou ◽  
W. Liu ◽  
X.F. Ye ◽  
H.F. Zai ◽  
...  

Citrus is a salt-sensitive plant. In the present study, the salt stress ameliorating the effect of arbuscular mycorrhizal fungi through antioxidant defense systems was reported. Three-month-old trifoliate orange (Poncirus trifoliata) seedlings colonized by Glomus mosseae or G. versiforme were irrigated with 0 and 100 mmol NaCl solutions. After 49 days of salinity, mycorrhizal structures were obviously restrained by salt stress. Mycorrhizal inoculation especially G. mosseae significantly alleviated the growth reduction of salinity. There were notably lower malondialdehyde and hydrogen peroxide contents in the leaves of mycorrhizal seedlings than in non-mycorrhizal ones. Mycorrhizal seedlings recorded notably greater activity of catalase and contents of ascorbate, soluble protein and glutathione under salinity or non-salinity conditions. The seedlings colonized by G. mosseae showed significantly higher antioxidant defense systems response to salinity than by G. versiforme. Our data demonstrate that mycorrhizal (especially G. mosseae) citrus seedlings exhibited greater efficient antioxidant defense systems, which provide better protection against salt damage.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1195
Author(s):  
Zornitsa Katerova ◽  
Iskren Sergiev ◽  
Dessislava Todorova ◽  
Elena Shopova ◽  
Ljudmila Dimitrova ◽  
...  

Waterlogging impairs crop development and considerably affects plant productivity worldwide. Wheat is sensitive to waterlogging. Serrate® (Syngenta) is a selective herbicide controlling annual grass and broadleaf weeds for use in wheat. To extend the existing information about the physiological effects of selective herbicides (Serrate® in particular) and subsequent waterlogging in wheat, we monitored phenotype alterations and examined key enzymatic and non-enzymatic antioxidant defense systems together with typical oxidative stress biomarkers. Seventeen-day-old wheat (Triticum asetivum L., cv. Sadovo-1) plants were sprayed with Serrate®; 72 h later, waterlogging was applied for 7 days, and then seedlings were left to recover for 96 h. The herbicide did not alter plant phenotype and increased antioxidant defense, along with H2O2 content, confirming the wheat’s tolerance to Serrate®. Evident yellowing and wilting of the leaves were observed at 96 h of recovery in waterlogged wheat, which were stronger in plants subjected to Serrate® + waterlogging. Waterlogging alone and herbicide + waterlogging gradually enhanced the content of stress markers (malondialdehyde, proline, and H2O2), non-enzymatic antioxidants (low-molecular thiols and total phenolics), and the activity of superoxide dismutase, guaiacol peroxidase, and glutathione reductase. The effects of herbicide + waterlogging were stronger than those of waterlogging alone even during recovery, suggesting that Serrate® interacted synergistically with the subsequently applied flooding.


2021 ◽  
Vol 4 (1) ◽  
pp. 70-83
Author(s):  
Mukund R. Shukla ◽  
Vikramjit S. Bajwa ◽  
Jose A. Freixas-Coutin ◽  
Praveen K Saxena

Salinity is a major environmental stress in agriculture with significantly detrimental effects on crop productivity. The development of strategies to enhance salinity stress tolerance in plants is essential to ensure crop production in saline environments. Melatonin (Mel) and serotonin (Ser) accumulate in response to environmental stresses and are presumed to play protective roles and improve growth of tissues during recovery. In this study, the effects of Mel and Ser were investigated in Arabidopsis under NaCl stress. Exogenous Mel (10 µM) and Ser (10 µM) treatment significantly increased fresh weight, lateral root number, and shoot height in A. thaliana seedlings exposed to NaCl stress (25 mM and 50 mM) compared to the non-treated control seedlings. In order to understand the role of these indoleamines in alleviating salt stress, we investigated the effects of Mel and Ser treatments on the expression of salt stress responsive genes including, transcription factors involved in abscisic acid (ABA) signaling pathway, ABA-INSENSITIVE 3 (ABI3)and ABA-INSENSITIVE 5 (ABI5); ABA responsive gene, RESPONSIVE TO DESSICATION 29B (RD29B), ABA-independent gene, RESPONSIVE TO DESSICATION 29A (RD29A) and Arabidopsis trithorax-like gene (ATX1) which function in stress responses via ABA-dependent and ABA-independent manner. Other genes included, ROS-signaling transcription factor ZAT10 and ZAT12, and the genes encoding ion transporters crucial for maintaining ion homeostasis, HIGH AFFINITY K+ TRANSPORTER 5 (HAK5) and SALT OVERLY SENSITIVE 1 (SOS1). Mel (10 µM) pre-treatment for 24 hrs followed by 50 mM salt treatment up-regulated ABI3, RD29B, ZAT12 and HAK5. The Ser (10 µM) pre-treatment significantly up-regulated ZAT12.These results indicate that indoleamine pre-treatment improved plant growth under salt stress with Mel facilitating salt tolerance via upregulation of ABA responsive genes, mediation of antioxidant defense systems to counteract the salt-induced ROS overproduction as well as controlling ion homeostasis. Although Ser displayed no significant effects on ABA signaling, it was found to increase the expression of antioxidant defense gene, ZAT12. This study demonstrates the importance of indoleamine pathway in mediation of salt stress response and provides the first indication of the involvement of Ser in salt stress tolerance. 


2020 ◽  
Vol 6 (11) ◽  
pp. 47-56
Author(s):  
N. Aliyeva

Antioxidant defense systems have been studied in the mesophyll (MC) and bundle sheath cell (BSC) chloroplasts of maize (Zea mays L.) leaves cultivated in an artificial climate chamber under various concentrations (0%, 1%, 2%, 3%) of NaCl. The amounts of some of the main products of lipid peroxidation malondialdehyde (MDA) and reactive oxygen species hydrogen peroxide (H2O2) as well as activities of superoxide dismutase (SOD) and ascorbate peroxidase (APO) were determined in MC and BSC chloroplasts. BSC chloroplasts were found to be more tolerant to salt stress compared with MC chloroplasts. The MDA amount increased in both chloroplasts. H2O2 was found to be localized mainly in MC chloroplasts at various NaCl concentrations. The SOD and APO activities increased in both chloroplasts of the plants exposed to salt stress.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1430
Author(s):  
Hao Wang ◽  
Liyan Liang ◽  
Baoxing Liu ◽  
Di Huang ◽  
Shuo Liu ◽  
...  

Salt stress inhibits photosynthetic process and triggers excessive formation of reactive oxygen species (ROS). This study examined the role of arbuscular mycorrhizal (AM) association in regulating photosynthetic capacity and antioxidant activity in leaves of two maize genotypes (salt-tolerant JD52 and salt-sensitive FSY1) exposed to salt stress (100 mM NaCl) in soils for 21 days. The leaf water content, chlorophyll content, and photosynthetic capacity in non-mycorrhizal (NM) plants were decreased by salt stress, especially in FSY1, with less reduction in AM plants than NM plants. Salinity increased the activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)) in both genotypes regardless of AM inoculation, but decreased the contents of non-enzymatic antioxidants (reduced glutathione (GSH) and ascorbate (AsA)), especially in FSY1, with less decrease in AM plants than NM plants. The AM plants, especially JD52, maintained higher photosynthetic capacity, CO2 fixation efficiency, and ability to preserve membrane integrity than NM plants under salt stress, as also indicated by the higher antioxidant contents and lower malondialdehyde (MDA)/electrolyte leakage in leaves. To conclude, the higher salt tolerance in AM plants correlates with the alleviation of salinity-induced oxidative stress and membrane damage, and the better performance of photosynthesis could have also contributed to this effect through reduced ROS formation. The greater improvements in photosynthetic processes and antioxidant defense systems by AM fungi in FSY1 than JD52 under salinity demonstrate genotypic variation in antioxidant defenses for mycorrhizal amelioration of salt stress.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 839
Author(s):  
Vitaliy B. Borisov ◽  
Sergey A. Siletsky ◽  
Martina R. Nastasi ◽  
Elena Forte

Reactive oxygen species (ROS) comprise the superoxide anion (O2·−), hydrogen peroxide (H2O2), hydroxyl radical (·OH), and singlet oxygen (1O2). ROS can damage a variety of macromolecules, including DNA, RNA, proteins, and lipids, and compromise cell viability. To prevent or reduce ROS-induced oxidative stress, bacteria utilize different ROS defense mechanisms, of which ROS scavenging enzymes, such as superoxide dismutases, catalases, and peroxidases, are the best characterized. Recently, evidence has been accumulating that some of the terminal oxidases in bacterial respiratory chains may also play a protective role against ROS. The present review covers this role of terminal oxidases in light of recent findings.


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