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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #424031
Research Project: Genetic Improvement of Lettuce, Spinach, Celery, Melon, and Related Species

Location: Crop Improvement and Protection Research

Title: Differential impact of SiO2 foliar application on lettuce response to temperature, salinity, and drought stress

Author
item Simko, Ivan
item Zhao, Rebecca
item PENG, HUI - University Of Florida

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2025
Publication Date: 6/16/2025
Citation: Simko, I., Zhao, R.B., Peng, H. 2025. Differential impact of SiO2 foliar application on lettuce response to temperature, salinity, and drought stress. Plants. 14(12). Article 1845. https://doi.org/10.3390/plants14121845.
DOI: https://doi.org/10.3390/plants14121845

Interpretive Summary: Lettuce is one of the most commercially important leafy vegetables globally, cultivated primarily in moderate climates. It is valued for its versatility in culinary use, predominantly as fresh leaves in salads, though certain types also feature edible stems. Prolonged periods of high temperature can disrupt lettuce growth and development, while drought stress can restrict water availability, disrupting key physiological processes. Elevated salinity inhibits plant and root growth, as well as seed germination. This study investigated how spraying lettuce plants with silicon dioxide (SiO2) affects their growth under stressful conditions like extreme temperatures, soil salinity, and drought in a controlled growth chamber environment. The research showed that silicon treatments generally boosted plant growth, particularly when the lettuce was struggling with high soil salt levels. Overall, silicon spray shows promise as a way to improve lettuce growth, especially under saline conditions, but using the correct amount is crucial, and it may not be helpful for drought stress. Further testing in field experiments is warranted.

Technical Abstract: Silicon dioxide (SiO2) foliar application can enhance lettuce resilience to temperature extremes, salinity, and drought. This study investigated SiO2 effects on three lettuce cultivars under varying temperature, salinity, and drought in a growth chamber. SiO2 treatment (3.66 mM) significantly increased plant biomass under suboptimal (15°C), optimal (20°C), and salinity stress. The greatest benefit was observed under severe salinity (100 mM NaCl), increasing plant weight, chlorophyll, and anthocyanin. Optimal alleviation of severe salinity stress consistently occurred at 3.66 mM SiO2, maximizing fresh weight, diameter, chlorophyll, and anthocyanin. Higher concentrations progressively diminished these benefits, with 29.30 mM reducing growth and increasing chlorosis. Under 100 mM salinity, 3.66 mM SiO2 promoted the highest K (20,406 mg/kg DW) and Na (16,185 mg/kg DW) accumulation while maintaining the highest K/Na ratio (1.26), suggesting enhanced ion compartmentalization. Unexpectedly, 3.66 mM SiO2 decreased plant fresh weight under severe drought (30% SWC). This study highlights silicon's potential for salinity stress mitigation, emphasizing concentration- and stress-specific approaches. Foliar SiO2 application could improve lettuce productivity under optimal and challenging conditions, warranting field validation and market assessments.