Fungal endophytes alleviate drought-induced oxidative stress in mandarin (Citrus reticulata L.): Toward regulating the ascorbate–glutathione cycle

Sadeghi, Fatemeh; Samsampour, Davood; Seyahooei, Majeed Askari; Bagheri, Abdoolnabi; Soltani, Jalal

doi:10.1016/j.scienta.2019.108991

Cited by 67 publications

(53 citation statements)

References 55 publications

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“…Various biotic and abiotic stresses in plants generate ROS and adversely affect plant growth. Endophytes have the ability to alleviate the drought and metal stress by modulating ROS scavenging system and thus improving the plant viability (Ma et al, 2019;Sadeghi et al, 2020). A diverse array of plants has been in a symbiotic relationship with endophytes.…”

Section: Discussionmentioning

confidence: 99%

Antiproliferative Role of Secondary Metabolites From Aspergillus unguis AG 1.1 (G) Isolated From Marine Macroalgae Enteromorpha sp. by Inducing Intracellular ROS Production and Mitochondrial Membrane Potential Loss Leading to Apoptosis

2020

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Drug resistance to the classically used chemotherapeutic drugs is the major challenge in their treatment of cancer needing the discovery of novel anticancer drugs. In terms of finding novel therapeutics, endophytes are quite promising as they are an excellent source of novel structures, which exhibit bioactivity. The present study demonstrated a dose-dependent antiproliferative activity of mycelial-derived secondary metabolites from a macroalgae associated endophyte Aspergillus unguis AG 1.1 (G). The antiproliferative activity of A. unguis mycelial extract (AUME) was observed on different human cancer cell lines. PI live/dead assay further confirmed the cytotoxic potential of the mycelial extract. Furthermore, AUME caused mitochondrial membrane aberration and generated ROS production as well indicating its potential to induce cell death by apoptosis. The metabolic profiling of the mycelial extract using GC-MS and LC-MS/MS revealed the presence of fatty acids, a benzoquinolinone derivative, imidazolidinedione derivative, diethyl phthalate and phthalate acid ester, a difuraxanthone, two prenylxanthone analogs and a phthalide derivative and some unknown metabolites. Presence of 4-(4-Hydroxy-3,5-dimethoxy-phenyl)-3,4-dihydro-1H-benzo[h]quinolin-2-one, 1-hydroxy-3,5-dimethoxy-2-prenylxanthone, 1,6-dihydroxy-3-methoxy-2-prenylxanthone and 3butylidene-7-hydroxyphthalide in AUME could be correlated to the notable cytotoxicity exhibited by the endophyte. The additional presence of many unidentified compounds heightened the prospects of finding some novel bioactive metabolites. Our results indicated that secondary metabolites produced by A. unguis AG 1.1 (G) have therapeutic potential as anticancer agents.

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Section: Discussionmentioning

confidence: 99%

Antiproliferative Role of Secondary Metabolites From Aspergillus unguis AG 1.1 (G) Isolated From Marine Macroalgae Enteromorpha sp. by Inducing Intracellular ROS Production and Mitochondrial Membrane Potential Loss Leading to Apoptosis

2020

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“…The oxidative injury to WT plants was mainly the result of high H 2 O 2 levels in transgene plants under drought conditions (Figure 7). Similarly, drought resulted in an increase in H 2 O 2 accumulation and lipid peroxidation [19][20][21]. The accumulation of ROS in water-stressed plants impairs the function of biochemical processes, damages organelles, and ultimately results in cell death [58].…”

Section: Discussionmentioning

confidence: 99%

“…We showed that KcTrxf -transgenic plants can scavenge the salt-elicited ROS in leaf cells through the upregulation of catalase and ascorbate peroxidase (APX) and can increase the activity of monodehydroascorbate reductase (MDAR) and glutathione reductase (GR) in the chloroplast ascorbate-glutathione (AsA-GSH) cycle [16][17][18], leading to an increase in reduced glutathione (GSH) and nonprotein thiols (NPTs) in the leaves [13]. Antioxidative systems also play an important role in scavenging ROS and in controlling the cellular redox potential against oxidative stress [19][20][21]. However, the regulatory roles of K. candel Trx family genes in osmotic and drought tolerance are not yet fully understood.…”

Section: Introductionmentioning

confidence: 99%

Kandelia candel Thioredoxin f Confers Osmotic Stress Tolerance in Transgenic Tobacco

Jing

Yao

et al. 2020

IJMS

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Water deficit caused by osmotic stress and drought limits crop yield and tree growth worldwide. Screening and identifying candidate genes from stress-resistant species are a genetic engineering strategy to increase drought resistance. In this study, an increased concentration of mannitol resulted in elevated expression of thioredoxin f (KcTrxf) in the nonsecretor mangrove species Kandelia candel. By means of amino acid sequence and phylogenetic analysis, the mangrove Trx was classified as an f-type thioredoxin. Subcellular localization showed that KcTrxf localizes to chloroplasts. Enzymatic activity characterization revealed that KcTrxf recombinant protein possesses the disulfide reductase function. KcTrxf overexpression contributes to osmotic and drought tolerance in tobacco in terms of fresh weight, root length, malondialdehyde (MDA) content, and hydrogen peroxide (H2O2) production. KcTrxf was shown to reduce the stomatal aperture by enhancing K+ efflux in guard cells, which increased the water-retaining capacity in leaves under drought conditions. Notably, the abscisic acid (ABA) sensitivity was increased in KcTrxf-transgenic tobacco, which benefits plants exposed to drought by reducing water loss by promoting stomatal closure. KcTrxf-transgenic plants limited drought-induced H2O2 in leaves, which could reduce lipid peroxidation and retain the membrane integrity. Additionally, glutathione (GSH) contributing to reactive oxygen species (ROS) scavenging and transgenic plants are more efficient at regenerating GSH from oxidized glutathione (GSSG) under conditions of drought stress. Notably, KcTrxf-transgenic plants had increased glucose and fructose contents under drought stress conditions, presumably resulting from KcTrxf-promoted starch degradation under water stress. We conclude that KcTrxf contributes to drought tolerance by increasing the water status, by enhancing osmotic adjustment, and by maintaining ROS homeostasis in transgene plants.

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“…Endophytes have stood out for their ability to synthesize and accumulate secondary metabolites in the tissues of their hosts which can influence the functioning of antioxidant enzymes, in turn activating the cascade of defense signals and promoting the positive regulation of gene expression of important enzymes during the production of secondary metabolites [ 221 ]. In this sense, several studies have shown that the association of endophytes increases tolerance to abiotic stresses [ 221 , 222 , 223 , 224 , 225 , 226 ].…”

Section: Endophytes In Inducing Tolerance To Abiotic Stressesmentioning

confidence: 99%

“…The role of endophytes in providing tolerance to water stress by regulating stress-inducible genes has been reported in Cucumis sativus [ 230 ], Zea mays [ 231 , 232 ], Oryza sativa [ 233 ], S. lycopersicum [ 234 ], Triticum aestivum [ 235 ], Citrus reticulata [ 225 ] and Saccharum officinarum [ 236 ]. The relief of water stress due to the action of endophytes may be the result of an increase in antioxidant enzymes, bioactive compounds, chlorophyll content, carotenoid content and chlorophyll fluorescence.…”

Section: Endophytes In Inducing Tolerance To Abiotic Stressesmentioning

confidence: 99%

Endophytic Fungi: Biological Control and Induced Resistance to Phytopathogens and Abiotic Stresses

et al. 2021

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Plant diseases cause losses of approximately 16% globally. Thus, management measures must be implemented to mitigate losses and guarantee food production. In addition to traditional management measures, induced resistance and biological control have gained ground in agriculture due to their enormous potential. Endophytic fungi internally colonize plant tissues and have the potential to act as control agents, such as biological agents or elicitors in the process of induced resistance and in attenuating abiotic stresses. In this review, we list the mode of action of this group of microorganisms which can act in controlling plant diseases and describe several examples in which endophytes were able to reduce the damage caused by pathogens and adverse conditions. This is due to their arsenal of molecules generated during the interaction by which they form a kind of biological shield in the plant. Furthermore, considering that endophytic fungi can be an important tool in managing for biotic and abiotic stresses due to the large amount of biologically active substances produced, bioprospecting this class of microorganisms is tending to increase and generate valuable products for agriculture.

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Fungal endophytes alleviate drought-induced oxidative stress in mandarin (Citrus reticulata L.): Toward regulating the ascorbate–glutathione cycle

Cited by 67 publications

References 55 publications

Antiproliferative Role of Secondary Metabolites From Aspergillus unguis AG 1.1 (G) Isolated From Marine Macroalgae Enteromorpha sp. by Inducing Intracellular ROS Production and Mitochondrial Membrane Potential Loss Leading to Apoptosis

Antiproliferative Role of Secondary Metabolites From Aspergillus unguis AG 1.1 (G) Isolated From Marine Macroalgae Enteromorpha sp. by Inducing Intracellular ROS Production and Mitochondrial Membrane Potential Loss Leading to Apoptosis

Kandelia candel Thioredoxin f Confers Osmotic Stress Tolerance in Transgenic Tobacco

Endophytic Fungi: Biological Control and Induced Resistance to Phytopathogens and Abiotic Stresses

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