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.

Ginger (Zingiber officinale Rosc.) is an important spice crop valued for its flavored and medical properties. It is susceptible to soil-borne diseases, which can cause considerable economic loss to growers. In vitro culture is feasible for the propagation of disease-free ginger plants, but has several disadvantages when producing seed rhizomes that can be commercially used, such as long cultivation cycles (usually 2–3 years) and occurrence of somaclonal variation. In this study, dynamic changes in the morphological characteristics of in vitro-propagated disease-free plants of ‘Wuling’ ginger were evaluated by continuous observation and measurement at 30-day intervals, and morphological variants were screened and characterized by agronomic, cytological, and molecular analysis at harvest. Results showed that the plants grew rapidly within 120 days after planting, and the most active growth period was from 60 to 120 days. Eight plants with clear and stable morphological differences were screened out from approximately 2000 plants grown in the field, and they could be classified into two groups (VT1 and VT2) based on tiller number, plant height, leaf color, and leaf shape. By flow cytometry analysis and chromosome counting, the VT1 was confirmed to be diploid, with the shortest plant height, the largest number of tillers and rhizome knobs, and the smallest tiller diameter and rhizome size among the three types of plants. The VT2 was mixoploid, consisting of diploid and tetraploid cells, with significantly reduced tiller number and rhizome knobs, significantly larger stomatal guard cells/apertures, and significantly lower stomatal density. SSR analysis detected DNA band profile changes in six out of the eight variants, including one plant of the VT1 and all the VT2 plants. The findings of this study might contribute to the commercial production of disease-free seed rhizomes in ginger, and the characterized somaclonal variants could provide useful germplasm resources for future breeding.

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.

Fusarium wilt, caused by Fusarium solani, is a devastating disease that leads to significant losses in ginger (Zingiber officinale) crops worldwide. To explore the molecular mechanisms underlying F. solani infection and disease progression, we performed a comparative transcriptome analysis of ginger rhizomes during storage, comparing inoculated and non-inoculated samples. A total of 647 and 6398 DEGs were identified in the 1.5- and 2-day infection groups, respectively. KEGG analysis revealed that most DEGs were enriched in the plant–pathogen interaction pathway, with both PTI and ETI being activated. Six DEGs in this pathway were validated by qRT-PCR at two time points, showing a strong correlation with FPKM values from the transcriptome data. Furthermore, transient expression analysis in Nicotiana benthamiana leaves demonstrated that overexpressing ZoCEBiP1 helped scavenge excess ROS, thereby reducing disease severity. Transcriptional profiling of DEGs in the plant–pathogen interaction pathway revealed significant changes in genes involved in ROS and NO metabolism. In F. solani-infected ginger rhizomes, levels of H₂O₂ and O₂⁻ were elevated, along with increased activities of antioxidant enzymes (POD, CAT, SOD, and APX) and higher NO content and NOS activity. These findings elucidated the early defense response of ginger rhizomes to F. solani infection and provided insights for developing effective strategies to manage fungal diseases.