Silicon Actuates Poplar Calli Tolerance after Longer Exposure to Antimony

Abstract

The presence of antimony (Sb) in high concentrations in the environment is recognized as an emerging problem worldwide. The toxicity of Sb in plant tissues is known; however, new methods of plant tolerance improvement must be addressed. Here, poplar callus (Populus alba L. var. pyramidallis) exposed to Sb(III) in 0.2 mM concentration and/or to silicon (Si) in 5 mM concentration was cultivated in vitro to determine the impact of Sb/Si interaction in the tissue. The Sb and Si uptake, growth, the activity of superoxide dismutase (SOD), catalase (CAT), guaiacol-peroxidase (G-POX), nutrient concentrations, and the concentrations of photosynthetic pigments were investigated. To elucidate the action of Si during the Sb-induced stress, the impact of short and long cultivations was determined. Silicon decreased the accumulation of Sb in the calli, regardless of the length of the cultivation (by approx. 34%). Antimony lowered the callus biomass (by approx. 37%) and decreased the concentrations of photosynthetic pigments (up to 78.5%) and nutrients in the tissue (up to 21.7%). Silicon supported the plant tolerance to Sb via the modification of antioxidant enzyme activity, which resulted in higher biomass production (increased by approx. 35%) and a higher uptake of nutrients from the media (increased by approx. 10%). Silicon aided the development of Sb-tolerance over the longer cultivation period. These results are key in understanding the action of Si-developed tolerance against metalloids.

Silicon nanoparticles vs trace elements toxicity: Modus operandi and its omics bases

“…In poplar callus exposed to Sb-stress, Si declined the content of Sb in the calli and supported overall callus growth and nutrient uptake as well as the content of photosynthetic pigments. The improved Sb tolerance was secured via the Si-induced modification of antioxidant enzyme activity ( Labancová et al., 2023 ). These findings also correspond to results obtained from the wild-type and the low-silica rice mutant cultivated with 10 or 30 μmol L −1 Sb ( Huang et al., 2012 ).…”