So, additional investigations to determine the SiNPs residue in the produced edible plant parts are urgently needed. In contrast, this study also showed that this treatment had considerable cytotoxic and genotoxic effects at this direct dose/concentration. These abnormal alterations were reduced in response to SiNPs spray. Observations of the transmission electron microscopy showed ultrastructural alterations in the cells of a grapevine leaf due to the infection with downy mildew, including plasmolysis and disruption of the cellular components, abnormal chloroplasts, and thickening of the cell wall and cell membrane. Scanning electron microscopy observations showed an increase up to 86.6% in the number of closed stomata and a reduction up to 55% in the average stomatal pore area in response to this treatment. Furthermore, this treatment led to an enhancement in the photosynthetic pigments, induction of phenolic and ascorbic acid contents, an increase in the activity of peroxidase and polyphenol oxidase enzymes, and a reduction in the cellular electrolyte leakage, lipid peroxidation, and H 2O 2 content. Shoot length and yield per grapevine were considerably enhanced recording up to 26.3 and 23.7% increase, respectively. Moreover, a reduction up to 81.5% in the disease severity was achieved in response to this treatment. The obtained results revealed that spraying of grapevines with SiNPs at 150 ppm significantly overexpressed the transcription factor jasmonate and ethylene-responsive factor 3 recording 8.7-fold, and the defense-related genes β-1,3-glucanase (11-fold), peroxidase (10.7-fold) pathogenesis-related-protein 1 (10.6-fold), and chitinase (6.5-fold). In addition, molecular, physiological, ultrastructural, and toxicity investigations were also conducted. In this study, the field application of silica nanoparticles (SiNPs) on Thompson Seedless grapevines (H4 strain) infected with downy mildew was evaluated.
Application of silicon- (Si-) based products have been extensively studied against various oomycete, fungal, bacterial, and viral plant diseases, but studies on Si application in their nanosize are limited.
3Viticulture Department, Horticulture Research Institute, Agricultural Research Center, Giza, Egypt.
2Department of Mycology Research and Plant Disease Survey, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt.1Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Egypt.
0 kommentar(er)
