Seed Priming with Single-Walled Carbon Nanotubes Grafted with Pluronic P85 Preserves the Functional and Structural Characteristics of Pea Plants

The engineering of carbon nanotubes in the last decades resulted in a variety of applications in electronics, electrochemistry, and biomedicine. A number of reports also evidenced their valuable application in agriculture as plant growth regulators and nanocarriers. In this work, we explored the effect of seed priming with single-walled carbon nanotubes grafted with Pluronic P85 polymer (denoted P85-SWCNT) on Pisum sativum (var. RAN-1) seed germination, early stages of plant development, leaf anatomy, and photosynthetic efficiency. We evaluated the observed effects in relation to hydro- (control) and P85-primed seeds. Our data clearly revealed that seed priming with P85-SWCNT is safe for the plant since it does not impair the seed germination, plant development, leaf anatomy, biomass, and photosynthetic activity, and even increases the amount of photochemically active photosystem II centers in a concentration-dependent manner. Only 300 mg/L concentration exerts an adverse effect on those parameters. The P85 polymer, however, was found to exhibit a number of negative effects on plant growth (i.e., root length, leaf anatomy, biomass accumulation and photoprotection capability), most probably related to the unfavorable interaction of P85 unimers with plant membranes. Our findings substantiate the future exploration and exploitation of P85-SWCNT as nanocarriers of specific substances promoting not only plant growth at optimal conditions but also better plant performance under a variety of environmental stresses.

Automated summary

In the past few decades, carbon nanotubes have been widely used in electronics, electrochemistry, and biomedicine. This study investigated the effect of seed priming with Pluronic P85 polymer grafted single-walled carbon nanotubes (P85-SWCNT) on Pisum sativum seed germination, plant development, leaf anatomy, and photosynthetic efficiency. The results showed that seed priming with P85-SWCNT did not negatively affect seed germination, plant development, leaf anatomy, biomass, and photosynthetic activity, but increased the number of active photosystem II centers in a concentration-dependent manner. However, P85 polymer exhibited negative effects on plant growth, possibly due to its unfavorable interaction with plant membranes. These findings suggest the potential of P85-SWCNT as nanocarriers for promoting plant growth and performance under various environmental stresses.