Silica nanoparticles (SiNPs) offer an ecofriendly and environmentally safe alternative for plant disease management. However, the mechanisms of SiNPs-induced disease resistance are largely unknown. This research evaluated the application of SiNPs in controlling the postharvest decay of ginger rhizomes inoculated with Fusarium solani. In vitro study showed that SiNP had little inhibitory effect on mycelial growth and spore germination of F. solani and did not significantly change mycelium’s MDA content and SDH activity. In vivo analysis indicated that SiNPs decreased the degree of decay around the wounds and decreased the accumulation of H2O2 after long-term pathogenic infection through potentiating the activities of antioxidant enzymes such as SOD, APX, PPO, and CAT. SiNP150 increased the CHI, PAL, and GLU activity at the onset of the experiment. Moreover, SiNP150 treatment increased total phenolics contents by 1.3, 1.5, and 1.2-times after 3, 5, and 7 days of treatment, and increased total flavonoids content throughout the experiment by 9.3%, 62.4%, 26.9%, 12.8%, and 60.8%, respectively. Furthermore, the expression of selected phenylpropanoid pathway-related genes was generally enhanced by SiNPs when subjected to F. solani inoculation. Together, SiNPs can effectively reduce the fungal disease of ginger rhizome through both physical and biochemical defense mechanisms.
Botanical pesticides have gradually become accepted for use in the control of agricultural pests. In order to clarify the active compounds of the ginger (Zingiber officinale) shoot extract (GSE) and its inhibitory effect on the growth of sorghum aphids (Melanaphis sorghi). In this study, LC-MS/MS was used to determine the major active compounds of the GSE, and leaf disc method was used to explore the insecticidal effect of the active compounds of ginger on sorghum aphids and the response mechanism of sorghum aphids. The results showed that phenolic acids were identified as the main active compounds, followed by flavonoids. The aphidicidal activity test using the above compounds found that 6-gingerol, and quercetin-3-O-rutinoside exhibited aphidicidal activity (GSE > quercetin-3-O-rutinoside > 6-gingerol). The growth of sorghum aphid was evaluated by using different concentrations of the GSE. It was found that with the increase of concentration and treatment time, the litter size, longevity and molting of aphids significantly decreased, and the mortality of aphids increased. The enzyme activity of aphids treated with 15 mg·mL−1 GSE was determined, and it was found that the GSE could significantly inhibit the activities of pepsin, lipase and α-amylase of aphids, while the activity of superoxide dismutase (SOD) was significantly activated. The activities of peroxidase (POD) and catalase (CAT) increased at first and then decreased. In detoxification enzymes, the carboxylesterase (CarE) activity was significantly activated, the acetylcholinesterase (AChE) activity was significantly inhibited, and the glutathione S-transferase (GST) activity increased at first and then decreased. The above results indicated that the GSE may become a botanical pesticide for aphid control and provide new resources for the development of aphid biological agents.
Ginger possesses both significant edible and medicinal value. Sprouting of ginger is a critical phase that influences the yield and quality of the crop. While silica nanoparticles (SiNPs) are known to promote the growth of ginger, their impact on sprouting remains unclear. The results show that sprouting 100 mg L−1 SiNPs (SiNP100) significantly improved ginger sprouting rate and respiratory intensity while reducing weight loss. It also elevated fructose, sucrose, and glucose contents, as well as sucrose phosphate synthase (SPS), sucrose synthase (SS), neutral invertase (NI), acid invertase (AI) activities, indicating that SiNP100 is associated with enhanced sprouting by modulating sugar metabolism. Concurrently, starch content decreased and α- and β-amylase activities increased. Hormonal profiling showed that SiNP100 increased auxin (IAA), trans-zeatin (TZR), isoamylalkenyladenin (IP), and gibberellic acid (GA3) levels, while decreasing abscisic acid (ABA), further supporting its role in promoting sprouting. RNA-seq and RT-qPCR validated that SiNP100 significantly enriched the plant hormone signal transduction and starch and sucrose metabolism pathways, upregulating genes related to sugar transport and metabolism (ZoSweet7, ZoSSIVa, ZoSPS1, and ZoSUS5). Field trials over two consecutive years confirmed that SiNP100 application improved ginger growth, photosynthesis, antioxidant capacity, and ultimately yield and quality. This study demonstrated the potential of SiNPs to improve seed sprouting and promote ginger growth under field conditions.
Aphis gossypii Glover (Homoptera: Aphidinae), a major pest of Chinese pepper (Zanthoxylum bungeanum Maxim), causes significant agricultural damage. Ginger (Zingiber officinale Roscoe) has shown potential as a source for developing botanical pesticides due to its strong bacteriostatic and insecticidal properties; however, the underlying mechanisms remain poorly understood. This study evaluated the repellent activity of ginger shoot extract (GSE) across four solvent phases—petroleum ether, trichloromethane, ethyl acetate, and methanol—against A. gossypii. The results demonstrated that GSE exhibited significant repellent effects, with the methanol phase showing the most pronounced activity. Twelve fractions were chromatographically separated from the methanol phase, and electroantennography (EAG) analysis revealed that fraction 4 induced strong EAG responses in both winged and wingless aphids. Further identification of active compounds in fraction 4 by gas chromatography–mass spectrometry (GC–MS) indicated the presence of terpenes, aromatics, alkanes, esters, and phenols as major constituents. Subsequent EAG analysis identified several key compounds—octahydro-pentalene (C1), (Z)-cyclooctene (C2), dimethylstyrene (C3), tetramethyl-heptadecane (C5), tetrahydro-naphthalene (C6), and heptacosane (C9)—as responsible for eliciting EAG responses in both aphid forms. Additionally, results from Y-tube olfactometer assays showed that (Z)-cyclooctene and heptacosane were significantly attractive, while octahydro-pentalene acted as a strong repellent to both winged and wingless aphids. These findings offer valuable insights for the development of synthetic attractants and repellents for A. gossypii and provide a theoretical foundation for utilizing ginger in the creation of botanical pesticides targeting this pest.