Evaluation of the effect of jasmonic acid elicitation on composition of pigments and biological activities in green callus of neem (Azadirachta indica)

Abstract

This study was carried out with the aim of determining the effects of jasmonic acid (JA) elicitation on the bioactive pigments' biosynthesis and the antioxidant activities in green callus of Azadirachta indica of two different ages (4- and 8-week-old). Plant tissue culture technique was employed to induce the formation of green callus from leaf explants of A. indica on Murashige and Skoog (MS) medium supplemented with 0.6 mg/L thidiazuron (CM) and three different concentrations of JA (2, 4, and 6 mg/L). The methanolic extracts from the green callus were used for determination of total chlorophyll content (TCh), total carotenoid content (TC), total anthocyanin content (TAC), total phenolic content (TPC), and total flavonoid content (TFC) through colorimetric and HPLC analyses. The highest amount of yield was obtained from CM and 2 mg/L JA (2JA) extracts for 4- and 8-week-old samples, respectively. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, and terpenoids in all 4- and 8-week-old samples elicited with 2, 4 and 6 mg/L JA. The highest value for TAC, TCh, TC, TPC, and TFC of 4- and 8-week-old samples were from callus cultured on media supplemented with 6 mg/L JA (6JA) and 4 mg/L JA (4JA), respectively. The lowest IC50 values were found to be 8.29 ± 0.10 mg/mL (6JA) for 4-week-old and 7.73 ± 0.03 mg/mL (4JA) for 8-week-old samples. The highest Ferric Reducing Antioxidant Power (FRAP) values obtained in this study were 90.60 ± 1.55 g/g (6JA), and 74.59 ± 3.91 g/g (4JA), respectively, for 4- and 8-week-old samples. Moreover, Pearson's correlation analysis revealed a significant correlation between TAC, TCh, TC, TPC, and TFC with ABTS and FRAP assays. In addition, PCA analysis revealed that 83.5% of the information (variances) contained in the data were retained by the first two principal components. Overall, these findings suggested that JA supplementation into the culture media significantly increase the chlorophyll, carotenoid, anthocyanin, phenolic and flavonoid contents and JA concentrations at 6 mg/L JA and 4 mg/L JA yielded the highest pigments content in 4- and 8-weeks-old callus, respectively.

Novel Jasmonic Acid–Coumarin Pathway in the Eggplant That Inhibits Vitellogenin Gene Expression To Prevent Mite Reproduction

“…32 Additionally, the exogenous application of JA and its derivatives to plants elicits a defense response that releases secondary metabolites with insecticidal properties, such as coumarin, vanillic acid, nicotine, and terpenoids. 20,21 From a pest control standpoint, phytohormones can partially alleviate pest-related harm and enhance plant resistance to herbivores while concurrently diminishing the ecological and human health consequences of chemical pesticide use, thereby introducing a novel approach to integrated pest management. 19,33,34 Conversely, from an economic perspective, JA can stimulate the production of advantageous secondary metabolites in plants, including transcriptional regulation of downstream genes in medicinal plants to generate drug components.…”

“…JA can enhance plant resistance against arthropods, pathogens, and plant diseases, thereby offering a novel perspective on the relationship and function of JA in the interaction between plants and herbivores . Additionally, the exogenous application of JA and its derivatives to plants elicits a defense response that releases secondary metabolites with insecticidal properties, such as coumarin, vanillic acid, nicotine, and terpenoids. , From a pest control standpoint, phytohormones can partially alleviate pest-related harm and enhance plant resistance to herbivores while concurrently diminishing the ecological and human health consequences of chemical pesticide use, thereby introducing a novel approach to integrated pest management. ,, Conversely, from an economic perspective, JA can stimulate the production of advantageous secondary metabolites in plants, including transcriptional regulation of downstream genes in medicinal plants to generate drug components . Our findings indicate that mite infestation increases the JA content in the eggplant as well as an elevation in coumarin levels following mite infestation and exogenous JA application.…”

“…As a critical phytohormone involved in plant defense, JA mediates plant resistance to insects and induces secondary metabolism, including the production of coumarins, alkaloids, flavonoids, and terpenoids. 20,21 These compounds elicit various effects on herbivores, such as luring, tending, poisoning, and egg killing, and can disrupt their normal physiological activities. 19,22 Furthermore, the infestation of mites elicits the JA-induced plant defense mechanism, and the JA level is positively correlated with the degree of plant resistance against mite herbivores.…”

“…Within the basal jasmonate signaling pathway, JASMONATE ZIM domain (JAZ) proteins function as transcriptional repressors by binding to transcription factors, thereby maintaining low levels of JA content. , However, when plants are exposed to external stimuli, such as herbivory or environmental changes or when they receive developmental signals, JA–Ile is rapidly synthesized and detected by the F-box protein CORONATINE INSENSITIVE 1 (COI1), which is a component of the Skp-Cullin-F-box (SCF) E3 ubiquitin ligase complex. , Subsequently, the SCFCOI1 complex recruits JAZ proteins for ubiquitination and subsequent degradation by the 26S proteasome. , Without JAZs, transcription factors are liberated to regulate downstream genes, activating JA-regulated defense and development pathways. As a critical phytohormone involved in plant defense, JA mediates plant resistance to insects and induces secondary metabolism, including the production of coumarins, alkaloids, flavonoids, and terpenoids. , These compounds elicit various effects on herbivores, such as luring, tending, poisoning, and egg killing, and can disrupt their normal physiological activities. , Furthermore, the infestation of mites elicits the JA-induced plant defense mechanism, and the JA level is positively correlated with the degree of plant resistance against mite herbivores. , …”

In vitro callus induction and evaluation of antioxidant activity of Rhinacanthus nasutus (L.) Kurz

“…Ahmad Fauzi etal. [ 44 ] reported that callus formation of Azadirachta indica that contained green pigment had higher bioactive pigment content and antioxidant potential activities compared with brown and cream callus, with TPC and TFC more highly correlated with FRAP than DPPH and ABTS radical scavenging activity. Thus, phenolic and flavonoid compounds of R. nasutus could be major factors in the FRAP assay.…”