TITLE:
Effect of Titanium Dioxide Nanoparticles on Growth and Biomass Accumulation in Lettuce (Lactuca sativa)
AUTHORS:
Channa B. Rajashekar, Brenden Armstrong
KEYWORDS:
Growth Characteristics, Lettuce, Nanoparticles, Titanium Dioxide, Toxicity
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.15 No.1,
January
5,
2024
ABSTRACT: The use of titanium dioxide nanoparticles (nTiO2)
is gaining interest in agriculture because of their impact on many aspects of
plant growth. The present study examines the effects of nTiO2 (5 nm
and 10 nm) applied to seeds and the seedlings as a foliar application on
various aspects of growth characteristics and biomass accumulation in lettuce (Lactuca
sativa, cv. Grand Rapids). Application of 10 nm nTiO2 to seeds
through imbibition resulted in a significant reduction in shoot biomass
accumulation while 5 nm nTiO2 did not affect the biomass
accumulation in lettuce. The application of 10 nm nTiO2 reduced the
fresh shoot biomass accumulation by about 18% compared to the control plants.
Other growth characteristics such as shoot dry biomass, root fresh and dry biomass,
plant height, and leaf area were not affected by the application of both 5 nm
and 10 nm nTiO2. In addition, foliar application of these
nanoparticles to the lettuce seedlings did not have a significant effect on
most of the growth parameters examined, and the increasing concentration
ranging from 5 nm/L to 400 mg/L did not produce a consistent response in
lettuce. Thus, nTiO2 application to lettuce seeds had a notable
negative impact on shoot growth while foliar application did not have a
significant effect on many plant growth characteristics. However, foliar
applications produced some symptoms of toxicity to the foliage in the form of
necrotic or chlorotic patches on the leaves, which were more pronounced with
increasing concentrations of both 5 nm and 10 nm nTiO2. However,
these symptoms were apparent at a concentration as low as 50 mg/L of nTiO2.
Thus, foliar application of nTiO2 may not have a significant impact
on many of the growth characteristics in lettuce, but it can result in foliar
toxicity.