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International Journal of Molecular... Jun 2019Salicylic acid (SA), as an enigmatic signalling molecule in plants, has been intensively studied to elucidate its role in defence against biotic and abiotic stresses.... (Review)
Review
Salicylic acid (SA), as an enigmatic signalling molecule in plants, has been intensively studied to elucidate its role in defence against biotic and abiotic stresses. This review focuses on recent research on the role of the SA signalling pathway in regulating cadmium (Cd) tolerance in plants under various SA exposure methods, including pre-soaking, hydroponic exposure, and spraying. Pretreatment with appropriate levels of SA showed a mitigating effect on Cd damage, whereas an excessive dose of exogenous SA aggravated the toxic effects of Cd. SA signalling mechanisms are mainly associated with modification of reactive oxygen species (ROS) levels in plant tissues. Then, ROS, as second messengers, regulate a series of physiological and genetic adaptive responses, including remodelling cell wall construction, balancing the uptake of Cd and other ions, refining the antioxidant defence system, and regulating photosynthesis, glutathione synthesis and senescence. These findings together elucidate the expanding role of SA in phytotoxicology.
Topics: Adaptation, Biological; Antioxidants; Cadmium; Disease Resistance; Photosynthesis; Plant Diseases; Plants; Reactive Oxygen Species; Salicylic Acid; Signal Transduction; Stress, Physiological
PubMed: 31216620
DOI: 10.3390/ijms20122960 -
Scientific Reports Oct 2021Hormones orchestrate the physiology of organisms. Measuring the activity of defense hormone-responsive genes can help understanding immune signaling and facilitate...
Hormones orchestrate the physiology of organisms. Measuring the activity of defense hormone-responsive genes can help understanding immune signaling and facilitate breeding for plant health. However, different from model species like Arabidopsis, genes that respond to defense hormones salicylic acid (SA) and jasmonic acid (JA) have not been disclosed in the soybean crop. We performed global transcriptome analyses to fill this knowledge gap. Upon exogenous application, endogenous levels of SA and JA increased in leaves. SA predominantly activated genes linked to systemic acquired resistance and defense signaling whereas JA mainly activated wound response-associated genes. In general, SA-responsive genes were activated earlier than those responding to JA. Consistent with the paradigm of biotrophic pathogens predominantly activating SA responses, free SA and here identified most robust SA marker genes GmNIMIN1, GmNIMIN1.2 and GmWRK40 were induced upon inoculation with Phakopsora pachyrhizi, whereas JA marker genes did not respond to infection with the biotrophic fungus. Spodoptera exigua larvae caused a strong accumulation of JA-Ile and JA-specific mRNA transcripts of GmBPI1, GmKTI1 and GmAAT whereas neither free SA nor SA-marker gene transcripts accumulated upon insect feeding. Our study provides molecular tools for monitoring the dynamic accumulation of SA and JA, e.g. in a given stress condition.
Topics: Cyclopentanes; Gene Expression; Gene Expression Profiling; Gene Expression Regulation, Plant; Oxylipins; Plant Growth Regulators; Salicylic Acid; Signal Transduction; Glycine max; Stress, Physiological; Transcriptome
PubMed: 34663865
DOI: 10.1038/s41598-021-00209-6 -
PloS One 2021Various phenolic compounds have been screened against Ganoderma boninense, the fungal pathogen causing basal stem rot in oil palms. In this study, we focused on the...
Various phenolic compounds have been screened against Ganoderma boninense, the fungal pathogen causing basal stem rot in oil palms. In this study, we focused on the effects of salicylic acid (SA) on the growth of three G. boninense isolates with different levels of aggressiveness. In addition, study on untargeted metabolite profiling was conducted to investigate the metabolomic responses of G. boninense towards salicylic acid. The inhibitory effects of salicylic acid were both concentration- (P < 0.001) and isolate-dependent (P < 0.001). Also, growth-promoting effect was observed in one of the isolates at low concentrations of salicylic acid where it could have been utilized by G. boninense as a source of carbon and energy. Besides, adaptation towards salicylic acid treatment was evident in this study for all isolates, particularly at high concentrations. In other words, inhibitory effect of salicylic acid treatment on the fungal growth declined over time. In terms of metabolomics response to salicylic acid treatment, G. boninense produced several metabolites such as coumarin and azatyrosine, which suggests that salicylic acid modulates the developmental switch in G. boninense towards the defense mode for its survival. Furthermore, the liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) analysis showed that the growth of G. boninense on potato dextrose agar involved at least four metabolic pathways: amino acid metabolism, lipid pathway, tryptophan pathway and phenylalanine pathway. Overall, there were 17 metabolites that contributed to treatment separation, each with P<0.005. The release of several antimicrobial metabolites such as eudistomin I may enhance G. boninense's competitiveness against other microorganisms during colonisation. Our findings demonstrated the metabolic versatility of G. boninense towards changes in carbon sources and stress factors. G. boninense was shown to be capable of responding to salicylic acid treatment by switching its developmental stage.
Topics: Alanine; Arecaceae; Carbohydrates; Carbon; Chromatography, Liquid; Cluster Analysis; Coumarins; Culture Media; Ganoderma; In Vitro Techniques; Ions; Lipids; Mass Spectrometry; Melanins; Phenols; Phenylalanine; Plant Diseases; Plant Roots; Salicylic Acid; Tryptophan
PubMed: 34972183
DOI: 10.1371/journal.pone.0262029 -
Frontiers in Bioscience (Landmark... Jan 2023wilt and blight are the most important diseases of chickpea. The current study was designed to investigate the individual and combined effect of salicylic acid (SA)...
BACKGROUND
wilt and blight are the most important diseases of chickpea. The current study was designed to investigate the individual and combined effect of salicylic acid (SA) with and to suppress wilt and promote growth of chickpea varieties: Thal-2006 and Punjab-2008.
METHODS
At the time of sowing, inoculum of was applied to the soil and the incidence of wilt was recorded after 60 days. The seeds were inoculated with and prior to sowing. Chickpea plants were treated with salicylic acid at seedling stage.
RESULTS
The combination of and SA significantly increased root length (166% and 145%), shoot height (50% and 47%) and shoot biomass (300% and 233%) in cv. Thal-2006 and cv. Punjab-2008, respectively, in infected plants. Similarly, the combined treatment of + SA, also enhanced the plant growth parameters of chickpea varieties. Maximum reduction in disease severity was observed in both + SA (90% and 84%) and + SA (79% and 77%) treatments in cv. Thal-2006 and Punjab-2008, respectively. Both + SA and + SA treatments resulted in increased leaf relative water and total protein content, peroxidase, superoxide dismutase, phenylalanine ammonia-lyase and polyphenol oxidase activities in both resistant (cv. Thal-2006) and susceptible (cv. Punjab-2008) cultivars. Both treatments also significantly reduced malondialdehyde (MDA) and proline content in cv. Thal-2006 and Punjab-2008. Cultivar Thal-2006 was more effective than cv. Punjab-2008.
CONCLUSIONS
The results suggested that, in combination, salicylic acid and may play an important role in controlling wilt diseases by inducing systemic resistance in chickpea.
Topics: Biomass; Cicer; Combined Modality Therapy; Fusarium; Malondialdehyde; Plant Diseases; Salicylic Acid; Pseudomonas; Agricultural Inoculants
PubMed: 36722276
DOI: 10.31083/j.fbl2801020 -
Journal of Experimental Botany Nov 2022Phytohormones are major signaling components that contribute to nearly all aspects of plant life. They constitute an interconnected communication network to fine-tune... (Review)
Review
Phytohormones are major signaling components that contribute to nearly all aspects of plant life. They constitute an interconnected communication network to fine-tune growth and development in response to the ever-changing environment. To this end, they have to coordinate with other signaling components, such as reactive oxygen species and calcium signals. On the one hand, the two endosymbiotic organelles, plastids and mitochondria, control various aspects of phytohormone signaling and harbor important steps of hormone precursor biosynthesis. On the other hand, phytohormones have feedback actions on organellar functions. In addition, organelles and phytohormones often act in parallel in a coordinated matter to regulate cellular functions. Therefore, linking organelle functions with increasing knowledge of phytohormone biosynthesis, perception, and signaling will reveal new aspects of plant stress tolerance. In this review, we highlight recent work on organelle-phytohormone interactions focusing on the major stress-related hormones abscisic acid, jasmonates, salicylic acid, and ethylene.
Topics: Plant Growth Regulators; Plants; Organelles; Abscisic Acid; Salicylic Acid
PubMed: 36169618
DOI: 10.1093/jxb/erac384 -
International Journal of Molecular... Dec 2022Grafting is widely applied to enhance the tolerance of some vegetables to biotic and abiotic stress. Salicylic acid (SA) is known to be involved in grafting-induced...
Grafting is widely applied to enhance the tolerance of some vegetables to biotic and abiotic stress. Salicylic acid (SA) is known to be involved in grafting-induced chilling tolerance in cucumber. Here, we revealed that grafting with pumpkin (, ) as a rootstock improved chilling tolerance and increased the accumulation of SA, abscisic acid (ABA) and hydrogen peroxide (HO) in grafted cucumber () leaves. Exogenous SA improved the chilling tolerance and increased the accumulation of ABA and HO and the mRNA abundances of , , , and . However, 2-aminoindan-2-phosphonic acid (AIP) and L-a-aminooxy-b-phenylpropionic acid (AOPP) (biosynthesis inhibitors of SA) reduced grafting-induced chilling tolerance, as well as the synthesis of ABA and HO, in cucumber leaves. ABA significantly increased endogenous HO production and the resistance to chilling stress, as proven by the lower electrolyte leakage (EL) and chilling injury index (CI). However, application of the ABA biosynthesis inhibitors sodium tungstate (NaWO) and fluridone (Flu) abolished grafting or SA-induced HO accumulation and chilling tolerance. SA-induced plant response to chilling stress was also eliminated by N,N'-dimethylthiourea (DMTU, an HO scavenger). In addition, ABA-induced chilling tolerance was attenuated by DMTU and diphenyleneiodonium (DPI, an HO inhibitor) chloride, but AIP and AOPP had little effect on the ABA-induced mitigation of chilling stress. NaWO and Flu diminished grafting- or SA-induced HO biosynthesis, but DMTU and DPI did not affect ABA production induced by SA under chilling stress. These results suggest that SA participated in grafting-induced chilling tolerance by stimulating the biosynthesis of ABA and HO. HO, as a downstream signaler of ABA, mediates SA-induced chilling tolerance in grafted cucumber plants.
Topics: Cucumis sativus; Abscisic Acid; Hydrogen Peroxide; Salicylic Acid; Advanced Oxidation Protein Products
PubMed: 36555697
DOI: 10.3390/ijms232416057 -
Molecular Plant Pathology Nov 2021During evolution, plants have developed sophisticated ways to cope with different biotic and abiotic stresses. Phytohormones and secondary metabolites are known to play... (Review)
Review
During evolution, plants have developed sophisticated ways to cope with different biotic and abiotic stresses. Phytohormones and secondary metabolites are known to play pivotal roles in defence responses against invading pathogens. One of the key hormones involved in plant immunity is salicylic acid (SA), of which the role in plant defence is well established and documented. Plants produce an array of secondary metabolites categorized in different classes, with the phenylpropanoids as major players in plant immunity. Both SA and phenylpropanoids are needed for an effective immune response by the plant. To successfully infect the host, pathogens secrete proteins, called effectors, into the plant tissue to lower defence. Secreted effectors can interfere with several metabolic or signalling pathways in the host to facilitate infection. In this review, we will focus on the different strategies pathogens have developed to affect the levels of SA and phenylpropanoids to increase plant susceptibility.
Topics: Plant Diseases; Plant Growth Regulators; Plant Immunity; Plants; Salicylic Acid
PubMed: 34414650
DOI: 10.1111/mpp.13123 -
International Journal of Molecular... Jan 2022Rice plants contain high basal levels of salicylic acid (SA), but some of their functions remain elusive. To elucidate the importance of SA homeostasis in rice immunity,...
Rice plants contain high basal levels of salicylic acid (SA), but some of their functions remain elusive. To elucidate the importance of SA homeostasis in rice immunity, we characterized four rice SA hydroxylase genes () and verified their roles in SA metabolism and disease resistance. Recombinant OsSAH proteins catalyzed SA in vitro, while OsSAH3 protein showed only SA 5-hydroxylase (SA5H) activity, which was remarkably higher than that of other OsSAHs that presented both SA3H and SA5H activities. Amino acid substitutions revealed that three amino acids in the binding pocket affected SAH enzyme activity and/or specificity. Knockout and (KO) genes conferred enhanced resistance to both hemibiotrophic and necrotrophic pathogens, whereas overexpression of each gene increased susceptibility to the pathogens. KO mutants showed increased SA and jasmonate levels compared to those of the wild type and -overexpressing plants. Analysis of the promoter indicated that its induction was mainly restricted around infection sites. Taken together, our findings indicate that SA plays a vital role in immune signaling. Moreover, fine-tuning SA homeostasis through suppression of SA metabolism is an effective approach in studying broad-spectrum disease resistance in rice.
Topics: China; Cyclopentanes; Dioxygenases; Disease Resistance; Gene Expression; Gene Expression Regulation, Plant; Hydroxylation; Oryza; Oxylipins; Plant Diseases; Plant Immunity; Plant Proteins; Plants, Genetically Modified; Salicylic Acid
PubMed: 35163275
DOI: 10.3390/ijms23031354 -
Brazilian Journal of Biology = Revista... 2023The present study aimed to evaluate concentrations and forms of application of salicylic acid used for water stress mitigation on the gas exchange and growth of yellow...
The present study aimed to evaluate concentrations and forms of application of salicylic acid used for water stress mitigation on the gas exchange and growth of yellow passion fruit. The experimental design was arranged in randomized blocks in a 4 × 4 × 2 factorial scheme, with four concentrations of salicylic acid (SA) via foliar application (0.0, 0.7, 1.4, and 2.1 mM), four SA concentrations via fertigation (0.0, 0.7, 1.4, and 2.1 mM), and two irrigation depths estimated based on the actual evapotranspiration - ETr (50 and 100% of ETr), with three replications. Water stress negatively affected the physiology and growth of yellow passion fruit seedlings at 75 days after sowing (DAS). The application of salicylic acid, regardless of the form of application, attenuates the effects of water stress on gas exchange and growth of yellow passion fruit, with the best results obtained when applying a concentration of 1.30 mM via leaf or 0.90 mM via fertirrigation. The combination of foliar application of AS and fertigation contributed to improve photosynthetic and growth parameters under water conditions of 50 and 100% of ETr. The foliar application of AS presents superior responses to the application via fertigation. These results reinforce the hypothesis that the attenuation of water stress by salicylic acid is related to the maintenance of gas exchange, which depends on the concentration and form of application, and studies testing combinations throughout the crop cycle become promising for advances in knowledge from the action of this phytohormone on abiotic stress.
Topics: Passiflora; Dehydration; Fruit; Seedlings; Salicylic Acid
PubMed: 37222368
DOI: 10.1590/1519-6984.270865 -
Current Opinion in Plant Biology Apr 2023The phytohormone salicylic acid (SA) is known to regulate plant immunity against pathogens. Plants synthesize SA via the isochorismate synthase (ICS) pathway or the... (Review)
Review
The phytohormone salicylic acid (SA) is known to regulate plant immunity against pathogens. Plants synthesize SA via the isochorismate synthase (ICS) pathway or the phenylalanine ammonia-lyase (PAL) pathway. The ICS pathway has been fully characterized using Arabidopsis thaliana, a model plant that exhibits pathogen-inducible SA accumulation. Many species including Populus (poplar) depend instead on the partially understood PAL pathway for constitutive as well as pathogen-stimulated SA synthesis. Diversity of SA-mediated defense is also evident in SA accumulation, redox regulation, and interplay with other hormones like jasmonic acid. This review highlights the contrast between Arabidopsis and poplar, discusses potential drivers of SA diversity in plant defenses, and offers future research directions.
Topics: Plants; Arabidopsis; Signal Transduction; Plant Growth Regulators; Salicylic Acid; Gene Expression Regulation, Plant; Plant Diseases; Cyclopentanes; Oxylipins
PubMed: 36842224
DOI: 10.1016/j.pbi.2023.102349