Salicylic Acid Treatment Research Articles

Hormonal Regulation and Transcriptomic Insights into Flower Development in Hydrangea paniculata 'Vanilla Strawberry'.

Understanding the molecular mechanisms that regulate flower growth, development, and opening is of paramount importance, yet these processes remain less explored at the genetic level. Flower development in Hydrangea paniculata 'Vanilla Strawberry' is finely tuned through hormonal signals, yet the genetic underpinnings are not well defined. This study addresses the gap by examining the influence of gibberellic acid (GA3), salicylic acid (SA), and ethylene (ETH) on the flowering traits and underlying molecular responses. Treatment with 100 mg/L SA significantly improved chlorophyll content and bolstered the accumulation of soluble sugars and proteins, advancing the flowering onset by 6 days and lengthening the flowering period by 11 days. Concurrently, this treatment enhanced inflorescence dimensions, increasing length, width, and petal area by 22.76%, 26.74%, and 27.45%, respectively. Contrastingly, 100 mg/L GA3 expanded inflorescence size but postponed flowering initiation and decreased inflorescence count. Higher concentrations of SA and GA3, as well as any concentration of ETH, resulted in delayed flowering and inferior inflorescence attributes. A physiological analysis over 50 days revealed that these regulators variably affected sugar and protein levels and modified antioxidant enzyme activities. An RNA-seq analysis during floral development highlighted significant transcriptomic reprogramming, with SA treatment downregulating Myb transcription factors, implicating them in the modulation of flowering timing and stress adaptation. These findings illuminate the complex interplay between hormonal treatments, gene expression, and flowering phenotypes in Hydrangea paniculata, offering valuable perspectives for ornamental horticulture optimization.

Extensive post-transcriptional regulation revealed by integrative transcriptome and proteome analyses in salicylic acid-induced flowering in duckweed (Lemna gibba).

Duckweed is an aquatic model plant with tremendous potential in industrial and agricultural applications. Duckweed rarely flowers which significantly hinders the resource collection and heterosis utilization. Salicylic acid (SA) can significantly induce duckweed to flower; however, the underlying regulatory mechanisms remain largely unknown. In this work, transcriptome and proteome were conducted in parallel to examine the expression change of genes and proteins in Lemna gibba under SA treatment. A high-quality reference transcriptome was generated using Iso-Seq strategy, yielding 42,281 full-length transcripts. A total of 422, 423, and 417 differentially expressed genes (DEGs), as well as 213, 51, and 92 differentially expressed proteins (DEPs), were identified at flower induction, flower initiation, and flowering stages by ssRNA-seq and iTRAQ methods. Most DEGs and DEPs were only regulated at either the transcriptomic or proteomic level. Additionally, DEPs exhibited low expression correlations with the corresponding mRNAs, suggesting that post-transcriptional regulation plays a pivotal role in SA-induced flowering in L. gibba. Specifically, the genes related to photosynthesis, stress, and hormone metabolism were mainly regulated at the mRNA level, those associated with mitochondrial electron transport / ATP synthesis, nucleotide synthesis, and secondary metabolism were regulated at the protein level, while those related to redox metabolism were regulated at the mRNA and/or protein levels. The post-transcriptional regulation of genes relevant to hormone synthesis, transcription factors, and flowering was also extensively analyzed and discussed. This is the first study of integrative transcriptomic and proteomic analyses in duckweed, providing novel insights of post-transcriptional regulation in SA-induced flowering of L. gibba.

The effects of chemical fungicides and salicylic acid on the apple microbiome and fungal disease incidence under changing environmental conditions.

Epiphytic and endophytic micro-organisms associated with plants form complex communities on or in their host plant. These communities influence physiological traits, development, and host susceptibility to abiotic and biotic stresses, and these communities are theorized to have evolved alongside their hosts, forming a unit of selection known as the holobiont. The microbiome is highly variable and can be influenced by abiotic factors, including applied exogenous agents. In this study, we compared the impact of chemical fungicide and salicylic acid treatments on the fungal communities of "Honeycrisp" apples at harvest over two consecutive growing years. We demonstrated variations in fungal community structure and composition by tissue type, growing season, and treatment regimes and that fungicide treatments were associated with reduced network complexity. Finally, we show that the inclusion of salicylic acid with 50% less chemical fungicides in an integrated spray program allowed a reduction in fungicide use while maintaining effective control of disease at harvest and following storage.

The potential application of biochar and salicylic acid to alleviate salt stress in soybean (Glycine max L.)

Salt stress has been one of the major contributor which affect soybean seed germination, its establishment, growth, and physiology stages. Utilization of strategies such as soil amendment and elicitors are of significant importance to reduce the disadvantageous effects of salt stress. In this regard, the objectives of the present study were to evaluate the effect of biochar and salicylic acid on morphological and physiological properties of soybean subjected to salinity. The first experiment was carried out based on completely randomized design with three replications including 11 soybean cultivars such as Williams, Saba, Kowsar, Tapor, Sari, Telar, Caspian, Nekador, Amir, Katol and Sahar and various levels of salinity such as 0, 2, 4, 6 dS/m of NaCl. The second experiment was performed as factorial design in a randomized complete block design with three replications consisting of treatments of biochar (0, 5 and 10 WP), salicylic acid (0, 0.5 and 1 mM), and NaCl (0, 2.5, 5, 7.5 dS/m). With respect to seed germination result, various concentrations of salt stress showed negative impact not only on all studied traits, but also varied among soybean cultivars indicating Amir cultivar as the best salt tolerant soybean genotype among others. In addition, our data exhibited that the interaction effect of biochar and salicylic acid on salt treated soybean plant were positively significant on some morphological traits such as leaf area, shoot dry/fresh weight, total dry/fresh weight and physiological attributes including chlorophyll a, flavonoid, proline contents, catalase and peroxidase activities. Moreover, the resultant data showed that the combination treatment of 5 and 10 WP of biochar and 1 mM of salicylic acid caused increase of the aforementioned parameters in order to improve their performance subjected to higher concentration of salinity. In final, it was concluded that the coupled application of biochar alongside salicylic acid was recommended as proficient strategy to mitigate the injurious influences of salt stress in soybean or other probable crops.

Callus proliferation-induced hypoxic microenvironment decreases shoot regeneration competence in Arabidopsis

Plants are aerobic organisms that rely on molecular oxygen for respiratory energy production. Hypoxic conditions, with oxygen levels ranging between 1% and 5%, usually limit aerobic respiration and affect plant growth and development. Here, we demonstrate that the hypoxic microenvironment induced by active cell proliferation during the two-step plant regeneration process intrinsically represses the regeneration competence of the callus in Arabidopsis thaliana. We showed that hypoxia-repressed plant regeneration is mediated by the RELATED TO APETALA 2.12 (RAP2.12) protein, a member of the Ethylene Response Factor VII (ERF-VII) family. We found that the hypoxia-activated RAP2.12 protein promotes salicylic acid (SA) biosynthesis and defense responses, thereby inhibiting pluripotency acquisition and de novo shoot regeneration in calli. Molecular and genetic analyses revealed that RAP2.12 could bind directly to the SALICYLIC ACID INDUCTION DEFICIENT 2 (SID2) gene promoter and activate SA biosynthesis, repressing plant regeneration possibly via a PLETHORA (PLT)-dependent pathway. Consistently, the rap2.12 mutant calli exhibits enhanced shoot regeneration, which is impaired by SA treatment. Taken together, these findings uncover that the cell proliferation-dependent hypoxic microenvironment reduces cellular pluripotency and plant regeneration through the RAP2.12–SID2 module.

Pre- and Post-harvest Elicitation with Methyl Jasmonate and Salicylic Acid Followed by Cold Storage Synergistically Improves Red Colour Development and Health-Promoting Compounds in Blood Oranges

Red blush is one of the key quality markers of blood orange fruit (Citrus sinensis L. Osbeck). Therefore, the influence of pre- (1, 2, and 3 mM) and postharvest (0.5, 1, and 1.5 mM) methyl jasmonate (MeJA) and salicylic acid (SA) (1, 2, and 3 mM) treatments on redness, colouring pigments, and health-promoting compounds in cold stored ‘Tarocco Ippolito’ blood oranges was investigated. Preharvest application of 3 mM MeJA significantly increased rind citrus colour index (CCI) by 43.3% and colorimetric coordinate a* (redness) by 3.1% and decreased h° (hue angle, 0 = red), L* (lightness), and b* (yellowness) by 13.7%, 12.6%, and 23.4%, respectively. This treatment also enhanced CCI (57.4%), reduced h° (16.5%) and L* (36.4%), and increased total anthocyanins (88%), monomeric anthocyanins (117%), and flavonoids (77%) in the juice. Postharvest dip of 1.5 mM MeJA (5 min) improved CCI of juice (53.6%) and a* (5.5%), reduced h° (15.9%), L* (19.8%), and b* (19.4%), and increased total anthocyanins (66.7%), monomeric anthocyanins (74%), and flavonoids (23.4%) in the juice. Preharvest application of 1 mM SA increased rind CCI (50.8%) and reduced L* (13.6%), b* (16.4%), and h° (29.5%). All preharvest SA treatments significantly increased total phenolics in the juice. Lycopene was increased (61.7%) by 5 min postharvest dip of 3 mM SA. In conclusion, 3 mM preharvest spray application of MeJA four weeks before harvest and postharvest dip of 1.5 mM MeJA (5 min) are effective in improving red colour of rind and juice and health-promoting compounds in blood orange juice.

Tulip transcription factor TgWRKY75 activates salicylic acid and abscisic acid biosynthesis to synergistically promote petal senescence.

WRKY transcription factors play a central role in controlling plant organ senescence; however, it is unclear whether and how they regulate petal senescence in the widely grown ornamental plant tulip (Tulipa gesneriana). In this study, we report that TgWRKY75 promotes petal senescence by enhancing the synthesis of both abscisic acid (ABA) and salicylic acid (SA) in tulip and in transgenic Arabidopsis. The expression level of TgWRKY75 was up-regulated in senescent petals, and exogenous ABA or SA treatment induced its expression. The endogenous contents of ABA and SA significantly increased during petal senescence and in response to TgWRKY75 overexpression. Two SA synthesis-related genes, TgICS1 and TgPAL1, were identified as direct targets of TgWRKY75, which binds to their promoters. In parallel, TgWRKY75 activated the expression of the ABA biosynthesis-related gene TgNCED3 via directly binding to its promoter region. Site mutation of the W-box core motif located in the promoters of TgICS1, TgPAL1, and TgNCED3 eliminated their interactions with TgWRKY75. In summary, our study demonstrates a dual regulation of ABA and SA biosynthesis by TgWRKY75, revealing a synergistic process of tulip petal senescence through feedback regulation between TgWRKY75 and the accumulation of ABA and SA.

Transcriptomic Analysis Reveals Candidate Genes in Response to Sorghum Mosaic Virus and Salicylic Acid in Sugarcane.

Sorghum mosaic virus (SrMV) is one of the most prevalent viruses deteriorating sugarcane production. Salicylic acid (SA) plays an essential role in the defense mechanism of plants and its exogenous application has been observed to induce the resistance against biotic and abiotic stressors. In this study, we set out to investigate the mechanism by which sorghum mosaic virus (SrMV) infected sugarcane responds to SA treatment in two sugarcane cultivars, i.e., ROC22 and Xuezhe. Notably, significantly low viral populations were observed at different time points (except for 28 d in ROC22) in response to post-SA application in both cultivars as compared to control based on qPCR data. Furthermore, the lowest number of population size in Xuezhe (20 copies/µL) and ROC22 (95 copies/µL) was observed in response to 1 mM exogenous SA application. A total of 2999 DEGs were identified, of which 731 and 2268 DEGs were up- and down-regulated, respectively. Moreover, a total of 806 DEGs were annotated to GO enrichment categories: 348 biological processes, 280 molecular functions, and 178 cellular components. GO functional categorization revealed that DEGs were mainly enriched in metabolic processes, extracellular regions, and glucosyltransferase activity, while KEGG annotation revealed that DEGs were mainly concentrated in phenylpropanoid biosynthesis and plant-pathogen interaction suggesting the involvement of these pathways in SA-induced disease resistance of sugarcane in response to SrMV infection. The RNA-seq dataset and qRT-PCR assay showed that the transcript levels of PR1a, PR1b, PR1c, NPR1a, NPR1b, PAL, ICS, and ABA were significantly up-regulated in response to SA treatment under SrMV infection, indicating their positive involvement in stress endorsement. Overall, this research characterized sugarcane transcriptome during SrMV infection and shed light on further interaction of plant-pathogen under exogenous application of SA treatment.

Effect of Salicylic Acid Foliar Application on Bioactive Compounds and Antioxidant Activity in Holy Basil (Ocimum sanctum L.)

Holy basil (Ocimum sanctum L.) has been used extensively in Thai traditional medicine, where it is commonly utilized as a part of herbal remedies for treating various ailments. Cultivation methods using exogenous salicylic acid (SA) to induce secondary metabolites have been documented in various plant species. Nevertheless, there is no reported information available on holy basil. Thus, the present study aimed to investigate the impact of SA foliar application on the bioactive compounds and antioxidant activity of holy basil. SA at concentrations of 0.1, 0.5, 1.0, 1.5, 2.0, and 2.5 mM was foliar sprayed 30 days after transplanting (DAT) compared to spraying with tap water as the control. The plants were harvested at 33 DAT. Exogenous SA at 0.1–1.5 mM enhanced the contents of bioactive compounds and improved antioxidant activity. The highest contents of eugenol (17,829.53 ± 243.11 μg/g dry extract), total phenolics (444.10 ± 2.80 mg GAE/g dry extract), and total flavonoids (382.69 ± 6.49 mg QE/g dry extract) were achieved at 1.0 mM SA foliar application, which was 282.96, 1.76, and 2.14 times, respectively, over control. Furthermore, the greatest antioxidant activity was observed in the 1.0 mM SA treatment. In contrast, the 2.0 and 2.5 mM SA treatments had lower levels of antioxidant activity and bioactive compounds than the control. The results of this study suggest that exogenous 1.0 mM SA foliar application is an effective method to produce enriched bioactivity in holy basil.

Genome-wide identification of the CONSTANS-LIKE (COL) family and mechanism of fruit senescence regulation by PpCOL8 in sand pear (Pyrus pyrifolia)

Pyrus pyrifolia Nakai ‘Whangkeumbae’ is a sand pear fruit with excellent nutritional quality and taste. However, the industrial development of pear fruit is significantly limited by its short shelf life. Salicylic acid (SA), a well-known phytohormone, can delay fruit senescence and improve shelf life. However, the mechanism by which SA regulates CONSTANS-LIKE genes (COLs) during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood. In this study, 22 COL genes were identified in sand pear, including four COLs (PpCOL8, PpCOL9a, PpCOL9b, and PpCOL14) identified via transcriptome analysis and 18 COLs through genome-wide analysis. These COL genes were divided into three subgroups according to the structural domains of the COL protein. PpCOL8, with two B-box motifs and one CCT domain, belonged to the first subgroup. In contrast, the other three PpCOLs, PpCOL9a, PpCOL9b, and PpCOL14, with similar conserved protein domains and gene structures, were assigned to the third subgroup. The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development. Moreover, the expression of PpCOL8 was inhibited by exogenous SA treatment, while SA up-regulated the expression of PpCOL9a and PpCOL9b. Interestingly, PpCOL8 interacts with PpMADS, a MADS-box protein preferentially expressed in fruit, and SA up-regulated its expression. While the production of ethylene and the content of malondialdehyde (MDA) were increased in PpCOL8-overexpression sand pear fruit, the antioxidant enzyme (POD and SOD) activity and the expression of PpPOD1 and PpSOD1 in the sand pear fruits were down-regulated, which showed that PpCOL8 promoted sand pear fruit senescence. In contrast, the corresponding changes were the opposite in PpMADS-overexpression sand pear fruits, suggesting that PpMADS delayed sand pear fruit senescence. The co-transformation of PpCOL8 and PpMADS also delayed sand pear fruit senescence. The results of this study revealed that PpCOL8 can play a key role in pear fruit senescence by interacting with PpMADS through the SA signaling pathway.

Salicylic acid enhances cell growth, fatty acid and astaxanthin production in heterotrophic Chromochloris zofingiensis without reactive oxygen species elevation

BackgroundThe induction of lipid and astaxanthin accumulation in microalgae is often achieved through abiotic stress. However, this approach usually leads to oxidative stress, which results in relatively low growth rate. Phytohormones, as important small molecule signaling substances, not only affect the growth and metabolism of microalgae but also influence the intracellular reactive oxygen species level. This study aimed to screen phytohormones that could promote the fatty acids and astaxanthin yield of heterotrophic Chromochloris zofingiensis without causing oxidative damage, and further investigate the underlying mechanisms.ResultsIn the present study, among all the selected phytohormones, the addition of exogenous salicylic acid (SA) could effectively promote cell growth along with the yield of total fatty acids (TFA) and astaxanthin in heterotrophic C. zofingiensis. Notably, the highest yields of TFA and astaxanthin were achieved at 100 μM SA, 43% and 97.2% higher compared with the control, respectively. Interestingly, the intracellular reactive oxygen species (ROS) levels, which are usually increased with elevated TFA content under abiotic stresses, were significantly decreased by SA treatment. Comparative transcriptome analysis unveiled significant alterations in overall carbon metabolism by SA. Specifically, the upregulation of fatty acid synthesis pathway, upregulation of β-carotene-4-ketolase (BKT) in carotenoid synthesis aligned with biochemical findings. Weighted gene co-expression network analysis highlighted ABC transporters and GTF2B-like transcription factor as potential key regulators.ConclusionThis study found that salicylic acid can serve as an effective regulator to promote the celling growth and accumulation of fatty acids and astaxanthin in heterotrophic C. zofingiensis without ROS elevation, which provides a promising approach for heterotrophic production of TFA and astaxanthin without growth inhibition.Graphical

Salicylic acid mitigates 'Hayward' kiwifruit chilling injury by regulating hormone and proline metabolism, as well as maintaining cellular structure

The 'Hayward' kiwifruit is extremely susceptible to chilling injury (CI) during the late stages of cold storage, thus limiting its storage quality and life. Therefore, mitigating the losses caused by CI is imperative. Salicylic acid (SA) has been demonstrated to mitigate CI in fruit and vegetables. In this study, we conducted a comparative analysis of proline metabolism, key endogenous hormone levels, as well as the effects on cell structure and membrane lipid oxidation in kiwifruit treated with 1 mM SA during low-temperature storage. The results showed that SA could attenuate lipoxygenase (LOX) activity, enhance catalase (CAT) activity, suppress the elevation of malondialdehyde (MDA) content, mitigate starch granule degradation in cells, and preserve cell structure integrity. Moreover, SA was found to enhance proline biosynthesis by activating ornithine transaminase (OAT) and pyrroline-5-carboxylate synthase (P5CS) while concurrently suppressing proline dehydrogenase (PDH) activity. Additionally, exogenous SA increased endogenous levels of both SA and abscisic acid (ABA), while simultaneously decreasing the concentration of gibberellic acid (GA) in fruit. In conclusion, exogenous SA treatment could alleviate the development of CI in kiwifruit by maintaining cell structure, promoting proline synthesis, and balancing endogenous hormone content. Our study offers a theoretical foundation for understanding the mechanism by which SA mitigates cold damage in kiwifruit, and provides novel insights into the low-temperature preservation of kiwifruit.

Optimization of salicylic acid concentrations for increasing antioxidant enzymes and bioactive compounds of Agastache rugosa in a plant factory.

Salicylic acid (SA) plays a crucial role as a hormone in plants and belongs to the group of phenolic compounds. Our objective was to determine the optimal concentration of SA for enhancing the production of bioactive compounds in Agastache rugosa plants while maintaining optimal plant growth. The plants underwent SA soaking treatments at different concentrations (i.e., 0, 100, 200, 400, 800, and 1600 μmol mol-1) for 10 min at 7 days after they were transplanted. We observed that elevated levels of SA at 800 and 1600 μmol mol-1 induced oxidative stress, leading to a significant reduction across many plant growth variables, including leaf length, width, number, area, shoot fresh weight (FW), stem FW and length, and whole plant dry weights (DW) compared with that in the control plants. Additionally, the treatment with 1600 μmol mol-1 SA resulted in the lowest values of flower branch number, FW and DW of flowers, and DW of leaf, stem, and root. Conversely, applying 400 μmol mol-1 SA resulted in the greatest increase of chlorophyll (Chl) a and b, total Chl, total flavonoid, total carotenoid, and SPAD values. The photosynthetic rate and stomatal conductance decreased with increased SA concentrations (i.e., 800 and 1600 μmol mol-1). Furthermore, the higher SA treatments (i.e., 400, 800, and 1600 μmol mol-1) enhanced the phenolic contents, and almost all SA treatments increased the antioxidant capacity. The rosmarinic acid content peaked under 200 μmol mol-1 SA treatment. However, under 400 μmol mol-1 SA, tilianin and acacetin contents reached their highest levels. These findings demonstrate that immersing the roots in 200 and 400 μmol mol-1 SA enhances the production of bioactive compounds in hydroponically cultivated A. rugosa without compromising plant growth. Overall, these findings provide valuable insights into the impact of SA on A. rugosa and its potential implications for medicinal plant cultivation and phytochemical production.

Salicylic Acid Treatment Improves the Shelf Life and Quality of ‘Cheonghyang’ Grapes during Cold Storage

The storage capacity of ‘Cheonghyang’ grapes, a promising grape cultivar developed in South Korea, is a critical factor affecting their commercial viability. This study investigates the impact of salicylic acid (SA) treatment on the storage capacity of ‘Cheonghyang’ grapes. The effects of SA treatment at different concentrations were assessed by comparing fruit characteristics and enzyme activity related to shelf life after two and four weeks of cold storage in comparison with an untreated control group. The findings reveal that SA-treated grapes exhibited reduced water loss and improved firmness, leading to a lower occurrence of unmarketable berries. Furthermore, enzymes involved in pectin degradation, such as pectate lyase and polygalacturonase, were reduced in the SA-treated group, while antioxidant activity-related enzymes, including catalase, peroxidase and superoxide dismutase, were more active than in the control group. The most effective control of enzyme activities was observed at an SA concentration of 2 mM, which demonstrated the least decline in fruit quality among the tested SA concentrations in this study. These results indicate that SA is a highly effective substance for maintaining the storability of ‘Cheonghyang’ grapes under conditions of low-temperature storage after harvest.

Impact of salicylic acid and sodium hydrosulfide applied singly or in combination on drought tolerance and grain yield in wheat plants

AbstractClimate change‐induced drought stress (DS) poses a significant threat to crop production, emphasizing the need for innovative strategies to mitigate its adverse effects. Prior studies have demonstrated the distinct capacities of salicylic acid (SA) and sodium hydrosulfide (NaHS) to augment plant resilience against drought‐related stressors. However, little is known about how they work together or the specific processes by which they increase DS tolerance. The purpose of this research was to determine how SA and NaHS affected the performance of wheat plants during the growing seasons of 2021–2022 and 2022–2023, when there was a drought. The research employed a block‐randomized experimental layout with split plots, where the primary factors included two irrigation levels: full irrigation (IW1, 100% of water requirement) and deficit irrigation (IW2, 50% of water requirement). Secondary factors included the application of mock control, 0.5 mM SA, and 0.3 mM NaHS, an H2S donor, either individually or in combination, administered before the onset of DS. The application of SA, NaHS, or their combination significantly enhanced wheat plant resistance to DS. Significant increases in a number of physiological markers, including proline content, relative water content (RWC), Fv/Fm, chlorophyll content, and antioxidant enzyme activity, demonstrated this improvement. Furthermore, in drought‐stressed wheat plants, SA and NaHS treatments decreased the amounts of hydrogen peroxide (H2O2), malondialdehyde (MDA) content, and electrolyte leakage (EL). In conclusion, our study highlights the possibility of SA and NaHS, whether applied individually or in combination, to improve drought resistance in wheat plants, presenting a viable approach to lessen the effects of climate change on agricultural yield.

The Effect of Foliar Spray Application with Salicylic Acid and Bacillus subtilis AB1 on The Growth and Protection of Grapevine Bushes from Powdery Mildew Disease Caused by the Fungal Pathogen Uncinula necator

El-Mosto, E., Z. Hassani and M. Abou Shaar. 2024. The Effect of Foliar Spray Application with Salicylic Acid and Bacillus subtilis AB1 on The Growth and Protection of Grapevine Bushes from Powdery Mildew Disease Caused by the Fungal Pathogen Uncinula necator. Arab Journal of Plant Protection, 42(3): 328-334. https://doi.org/10.22268/AJPP-001244 This study was conducted to evaluate the effect of foliar spray with three concentrations of salicylic acid (100, 200 and 300 mg/L), Bacillus subtilis AB1 at a concentration 2×106 cfu/ml, and the combined mutual effect of both, compared with a farmer's control on vegetative growth, clusters weight, productivity, and reduction of powdery mildew disease spread on grape vines. The growth length was significantly increased (140.7 cm) by applying the foliar spray of the bacteria + salicylic acid (200 mg/L) compared to the two treatments of salicylic acid 100 mg/L and the farmer's control (55.2 and 82.5 cm, respectively), whereas no significant differences were obtained between them and the rest of the treatments. The foliar spray with the treatment of both components (bacteria + salicylic acid 300 mg/L) was superior to all studied concentrations in relation to the average leaf surface area, clusters weight and productivity. All studied treatments reduced the severity of powdery mildew infection on leaves, except for salicylic acid at 200 mg/L (0.19) and no significant differences were recorded between all treatments (0.11-0.12) except for the two treatments (bacteria alone and farmer's control (0.15 and 0.14), respectively, in terms of reducing disease the severity of infection on fruit clusters. Keywords: Grapevine, salicylic acid, Bacillus subtilis AB1, vegetative growth, productivity, powdery mildew

Exogenous salicylic acid treatment enhances the disease resistance of Panax vietnamensis by regulating secondary metabolite production.

Salicylic acid (SA) is a phenolic compound widely found in plants. It plays a key role in exerting plant disease resistance. Panax vietnamensis Ha & Grushv., a valuable medicinal plant, contains high levels of phenolic compounds, which contribute significantly to the resilience of the plant against stress. However, the precise role of SA in regulating the synthesis of secondary metabolites in P.vietnamensis remains elusive. Two-year-old P. vietnamensis seedlings were treated with exogenous SA. We systematically assessed the changes in the physiological parameters of SA-treated P. vietnamensis leaves, employing transcriptome and metabolome analyses to elucidate the underlying mechanisms. Our results revealed a significant improvement of the plant's antioxidant capacity at 6 h post-treatment. Furthermore, exogenous SA treatment promoted the biosynthesis of lignin and flavonoids such as rutin, coumarin, and cyanidin. In addition, it increased the levels of endogenous SA and jasmonic acid (JA), promoting the disease resistance of the plants. Thus, SA pretreatment enhanced the defense of P. vietnamensis against pathogens. Our study provided novel insights into the potential molecular mechanisms underlying SA-mediated biosynthesis of secondary metabolites. Furthermore, our results provided a theoretical foundation for optimizing the cultivation practices of P.vietnamensis and the application of SA as a plant immunomodulator.

Salicylic acid treatment inhibits cold-induced sweetening by regulating the transcription factors StAP2/ERF and StNAC2 in potato

Abstract Cold-induced sweetening (CIS) results in browning and acrylamide formation in fried potato products. β-Amylase (BAM) and vacuolar invertase (INV) are crucial for starch–sugar conversion in cold-stored potatoes. This research investigates the effects of salicylic acid (SA) treatment on the CIS of potatoes and gene regulation during this process. The findings revealed that the SA treatment significantly alleviated CIS by suppressing StBAM1 and StINV1 expression in potato. Moreover, the expression of two transcription factors (TFs), StAP2/ERF and StNAC2, was inhibited by SA treatment. Transient overexpression of StAP2/ERF (AP2: APETALA2; ERF: ethylene responsive factor) and StNAC2 in tobacco leaves increased the expression of NtBAM1 and NtINV, thus promoting starch–sugar conversion. Furthermore, the β-glucuronidase (GUS) activity demonstrated that StAP2/ERF and StNAC2 increased the promoter activity of StBAM1 and StINV1. This study identifies new TFs in CIS regulation and provides new ideas for alleviating CIS in potato.

Utilizing Plant-Derived Salicylic Acid to Inhibit Leafminer Moth (Noorda blitealis Walker) Infestation on Moringa Oleifera

The experimental trial was conducted at Sakab Farm Limited Satame, Makoda Local Government. Kano State (12°18’20’’N, 8°36’30’’E / 12°16’0’’N, 8°27’50’’E), from October, 2021 to November, 2022. The experiments were established in various field cages in a split plot design with various levels of Salicylic acid (SA) treatments representing the main plots and the spray regimes: 1 weeks after spray (1-WAS), 2 weeks after spray (2-WAS) and 3 weeks after spray (3-WAS), as subplots. Different Concentrations of SA (5mg/l, 10mg/l and 20mg/l) were extracted from plant sources and formed by serial dilution. Ten freshly emerged larvae of Noorda blitealis collected from infested fields were introduced into each of the treatment group containing the treated stands of drumstick. The set up was undisturbed but observed at regular intervals. The results shows that, mean percentage leaves damage varied significantly (P<0.001) among different concentrations of SA and the spray regimes. Larval development time was significantly (P<0.05) prolonged in the higher concentration (20mg/l. SA) and median spray regime (2-WAS). The mean percentage leaves damage and progeny emergence of the moths were considerably low at the same treatment combinations. Moringa plants treated with higher concentrations of SA were also less infested and apparently more tolerant than the other treatments owing to their lower index of susceptibilities. This facility should be incorporated into the integrated control for effective management of Insect pest.

Effect on Yield and Alkaloid Content of Salicylic Acid Treatment in Different Growth Periods of Poppy

Amaç: Araştırma, haşhaşın farklı gelişme dönemlerinde salisilik asit uygulamasının, bitkisel özellikler, tohum verimi ve bazı alkaloitlerin içeriği üzerine etkisini araştırmak amacıyla yürütülmüştür.
 Materyal ve Yöntem: Çalışmada; TMO2 haşhaş çeşidi kullanılarak, geleneksel gübreleme üzerine rozet, sapa kalkma, rozet + sapa kalkma, tomurcuklanma, sapa kalkma + tomurcuklanma ve rozet+sapa kalkma+ tomurcuklanma dönemlerinde 100 ppm’lik salisilik asit uygulanmıştır.
 Araştırma Bulguları: Haşhaşın farklı gelişme dönemlerinde salisilik asit uygulamasının bitki boyu dışında incelenen özelliklere etkisi, istatistiksel olarak önemli (P