Multi-Walled Carbon Nanotubes Can Promote Brassica napus L. and Arabidopsis thaliana L. Root Hair Development through Nitric Oxide and Ethylene Pathways

Abstract

Here, we report that multi-walled carbon nanotubes (MWCNTs) can promote plant root hair growth in the species analyzed in this study; however, low and excessive concentrations of MWCNTs had no significant effect or even an inhibiting influence. Further results show that MWCNTs can enter rapeseed root cells. Meanwhile, nitrate reductase (NR)-dependent nitric oxide (NO) and ethylene syntheses, as well as root hair formation, were significantly stimulated by MWCNTs. Transcription of root hair growth-related genes were also modulated. The above responses were sensitive to the removal of endogenous NO or ethylene with a scavenger of NO or NO/ethylene synthesis inhibitors. Pharmacological and molecular evidence suggested that ethylene might act downstream of NR-dependent NO in MWCNTs-induced root hair morphogenesis. Genetic evidence in Arabidopsis further revealed that MWCNTs-triggered root hair growth was abolished in ethylene-insensitive mutants ein2-5 and ein3-1, and NR mutant nia1/2, but not in noa1 mutant. Further data placed NO synthesis linearly before ethylene production in root hair development triggered by MWCNTs. The above findings thus provide some insights into the molecular mechanism underlying MWCNTs control of root hair morphogenesis.

Carbon Nanomaterials for Plant Priming through Mechanostimulation: Emphasizing the Role of Shape

“…29 Treating rapeseed seedlings with 100 mg/L multiwalled carbon nanotubes for 12 h induced a gradual increase in ET production in 3 days, which coincided with increased activities of enzymes involved in ET biosynthesis and regulation. 30 The absence of a wound response in these studies might have occurred because this reaction usually starts within minutes to hours after plant injury. Studies often concentrate on producing defensive compounds, such as secondary metabolites, which can take days to weeks and vary based on the wound's severity and plant species.…”

“…After 6-week-old A. thaliana leaves were infiltrated with SWNTs (50 mg/L) for 48 h, transcriptome analysis revealed that genes linked to immune responses and biotic and abiotic stress responses were notably upregulated . Treating rapeseed seedlings with 100 mg/L multiwalled carbon nanotubes for 12 h induced a gradual increase in ET production in 3 days, which coincided with increased activities of enzymes involved in ET biosynthesis and regulation . The absence of a wound response in these studies might have occurred because this reaction usually starts within minutes to hours after plant injury.…”

Nanomaterials as Nanofertilizers and Nanopesticides: An Overview

“…the results of another study revealed that the entrance of MWCNTs into rapeseed (Brassica napus) root cells leads to the synthesis of nitric oxide and ethylene, thus significantly stimulating plant root hair growth . [78] of traditional pesticides on human and environmental components.…”