Biochemical and phytochemical responses of Ammi visnaga L. (Apiaceae) callus culture elicited by SiO2 and graphene Oxide-SiO2 nanoparticles

Graphene Oxide Nanoparticle-Assisted Promotion of Stevioside, Rebaudioside A, and Selected Biochemical Attributes in Stevia rebaudiana Bertoni

Stevia rebaudiana Bert. is commonly known as candy leaf, sugar leaf, or sweet leaf. It is a natural sweetener that has low calories and is used as a substitute for sucrose. The objective of this research is to evaluate the effects of graphene oxide (GO) on the growth, biochemical activities, and stevioside and rebaudioside A production of Stevia in in vitro-raised plantlets. For this, green nanomaterials of GO (0, 2, 4, 6, 8, and 10 mgL-1) were applied to the in vitro plants to enhance its sweetness by triggering the production of stevioside and rebaudioside A and other growth and biochemical parameters. It was observed that all the growth parameters of Stevia plants significantly increased with all GO treatments tested. Total chlorophyll and protein contents were increased (1.85- and 2.65-fold increase from the control) by applying 8 mgL-1 of GO to the MS medium. The maximum value (4 mg·g-1 of protein) of peroxidase activity (POD) was observed by applying 4 mgL-1 of GO, 28.92-fold increase from the control. In comparison, superoxide dismutase activity (SOD) (0.4 mg·g-1 protein) was observed with 10 mgL-1 of GO (1.56-fold increase from the control). Stevioside (12.9 and 8.9 mg·g-1 DW) and rebaudioside A (3.2 and 0.81 mg·g-1 DW) were observed only at 6 and 8 mg·L-1 treatment of graphene oxide. According to the findings, using graphene oxide (GO) had a significant impact on the growth, biochemical activities, and steviol glycoside production in Stevia. This shows that GO has the potential to be a valuable enhancer of sweetness and overall Stevia leaf quality, providing great prospects for the development of low-calorie natural sweeteners.

Unraveling a Small Secreted Peptide SUBPEP3 That Positively Regulates Salt-Stress Tolerance in Pyrus betulifolia

Small secreted peptides (SSPs) play important roles in regulating plants' growth and development in response to external stimulus, but the genes and functions of SSPs in many species are still unknown. Therefore, it is particularly significant to characterize and annotate SSP genes in plant genomes. As a widely used stock of pears, Pyrus betulifolia has strong resistance to biotic and abiotic stresses. In this study, we analyzed the SSPs genes in the genome of P. betulifolia according to their characteristics and homology. A total of 1195 SSP genes were identified, and most of them are signaling molecules. Among these, we identified a new SSP, subtilase peptide 3 (SUBPEP3), which derived from the PA region of preSUBPEP3, increasing the expression level under salt stress. Both adding synthetic peptide SUBPEP3 to the culture medium of pears and the overexpression of SUBPEP3 in tobacco can improve the salt tolerance of plants. In summary, we annotated the SSP genes in the P. betulifolia genome and identified a small secreted peptide SUBPEP3 that regulates the salt tolerance of P. betulifolia, which provides an important theoretical basis for further revealing the function of SSPs.

Dynamic interplay of metal and metal oxide nanoparticles with plants: Influencing factors, action mechanisms, and assessment of stimulatory and inhibitory effects

Nanoparticles (NPs) of metals and metal oxides have received increasing attention regarding their characteristic behavior in plant systems. The fate and transport of metal NPs and metal oxide NPs in plants is of emerging concern for researchers because they ultimately become part of the food chain. The widespread use of metal-based NPs (MBNPs) in plants has revealed their beneficial and harmful effects. This review addresses the main factors affecting the uptake, translocation, absorption, bioavailability, toxicity, and accumulation of MBNPs in different plant species. It appraises the mechanism of nanoparticle-plant interaction in detail and provides understanding of the estimation strategies for the associated pros and cons with this interplay. Critical parameters of NPs include, but are not limited to, particle size and shape, surface chemistry, surface charge, concentration, solubility, and exposure route. On exposure to MBNPs, the molecular, physiological, and biochemical reactions of plants have been assessed. We have filled knowledge gaps and answered research questions regarding the positive and negative effects of metal and metal oxide NPs on seed germination, callus induction, growth and yield of plant, nutritional content, antioxidants, and enzymes. Besides, the phytotoxicity, cytotoxicity, genotoxicity, and detoxification studies of MBNPs in plants have been outlined. Furthermore, the recent developments and future perspectives of the two-way traffic of interplay of MBNPs and plants have been provided in this comprehensive review.

Chemical Composition, Antioxidant, Anticancer, and Antibacterial Activities of Roots and Seeds of Ammi visnaga L. Methanol Extract

For centuries, plants and their components have been harnessed for therapeutic purposes, with Ammi visnaga L. (Khella) being no exception to this rich tradition. While existing studies have shed light on the cytotoxic and antimicrobial properties of seed extracts, there remains a noticeable gap in research about the antimicrobial, antioxidant, and anticancer potential of root extracts. This study seeks to address this gap by systematically examining methanol extracts derived from the roots of A. visnaga L. and comparing their effects with those of seed extracts specifically against breast cancer cells. Notably, absent from previous investigations, this study focuses on the comparative analysis of the antimicrobial, antioxidant, and anticancer activities of both root and seed extracts. The methanol extract obtained from A. visnaga L. seeds demonstrated a notably higher level of total phenolic content (TPC) than its root counterpart, measuring 366.57 ± 2.86 and 270.78 ± 2.86 mg GAE/g dry weight of the dry extract, respectively. In the evaluation of antioxidant activities using the DPPH method, the IC50 values for root and seed extracts were determined to be 193.46 ± 17.13 μg/mL and 227.19 ± 1.48 μg/mL, respectively. Turning our attention to cytotoxicity against breast cancer cells (MCF-7 and MDA-MB-231), both root and seed extracts displayed similar cytotoxic activities, with IC50 values of 92.45 ± 2.14 μg/mL and 75.43 ± 2.32 μg/mL, respectively. Furthermore, both root and seed extracts exhibited a noteworthy modulation of gene expression, upregulating the expression of caspase and Bax mRNA levels while concurrently suppressing the expression of anti-apoptotic genes (Bcl-xL and Bcl-2), thereby reinforcing their potential as anticancer agents. A. visnaga L. seed extract outperforms the root extract in antimicrobial activities, exhibiting lower minimum inhibitory concentrations (MICs) of 3.81 ± 0.24 to 125 ± 7.63 μg/mL. This highlights the seeds' potential as potent antibacterial agents, expanding their role in disease prevention. Overall, this study underscores the diverse therapeutic potentials of A. visnaga L. roots and seeds, contributing to the understanding of plant-derived extracts in mitigating disease risks.

Biochemical changes and enhanced accumulation of phenolic compounds in cell culture of Perilla frutescens (L.) by nano-chemical elicitation

Perilla frutescens (L.) Britt is a renowned medicinal plant with pharmaceutically valuable phenolic acids and flavonoids. The present study was aimed to study the eliciting effect of silver and copper nanoparticles (AgNPs and CuNPs, 50 and 100 mg/L), and methyl jasmonate (MeJa, 50 and 100 μM) on the biochemical traits, the accumulation of phenolic compounds and antioxidative capacity of P. frutescens cell suspension culture. Suspension cells were obtained from friable calli derived from nodal explants in Murashige and Skoog (MS) liquid medium containing 1 mg/L 2,4-D and 1 mg/L BAP. The 21 days old cell suspension culture established from nodal explant derived callus supplemented with 100 mg/L MeJa resulted in the highest activity of catalase and guaiacol peroxidase enzymes, and CuNPs 100 mg/L treated cells indicated the maximum content of total phenol, total anthocyanin, superoxide dismutase, malondialdehyde, and H2O2. Also, the highest content of ferulic acid (1.41 ± 0.03, mg/g DW), rosmarinic acid (19.29 ± 0.12, mg/g DW), and phenylalanine ammonia-lyase (16.81 ± 0.18, U/mg protein) were observed with 100 mg/L CuNPs, exhibiting a total increase of 1.58-fold, 2.12-fold, and 1.51-fold, respectively, higher than untreated cells. On the other hand, AgNPs 100 mg/L treated cells indicated the most amounts of caffeic acid (0.57 ± 0.03, mg/g DW) and rutin (1.13 ± 0.07, mg/g DW), as well as the highest scavenging potential of free radicals. Overall, the results of the present study can be applied for the large-scale production of valuable phenolic acids and flavonoids from P. frutescens through CuNPs and AgNPs 100 mg/L elicited cell suspension cultures.