A Novel Mechanism Underlying Multi-walled Carbon Nanotube-Triggered Tomato Lateral Root Formation: the Involvement of Nitric Oxide

Table 1 Different responses in LR formation triggered by nanomaterials

Materials	OD (nm)	ID (nm)	Length (μm)	Species	Concentration	Effect on LR formation	Article(s)
MWCNTs	6–12	2.5–5	1–9	Solanum lycopersicum	5000 mg/L	Promotion	This study
MWCNTs	20–70	5–10	> 2	Glycine max	1000 mg/L	Inhibition	[40]
MWCNTs	6–13	2–6	2.5–20	Lupinus elegans; Eysenhardtia polystachya	10–50 μg/mL	Promotion	[41]
MWCNTs	About 9.5	–	< 1	Lactuca sativa	5–20 mg/L	Promotion	[42]
MWCNTs	30–40	–	–	Arabidopsis thaliana	50 mg/L	Promotion	[43]
Au NP	20–50	–	–	Gloriosa superba	500–1000 μM	Promotion	[44]
ZnO NP	< 100	–	< 1	Triticum aestivum	125–500 mg/L	Promotion	[45]
ZnO NP	< 50	–	–	Cicer arietinum	100–1000 ppm	Inhibition	[46]
TiO₂ NP	< 50	–	–	Cicer arietinum	100–1000 ppm	Promotion	[46]
GO	50–200	–	–	Oryza sativa; Malus domestica	0.01–1 mg/L, 5–50 mg/L, 0.1–10 mg/L	Promotion Inhibition	[47,48,49]

Au NP, gold nanoparticles; ZnO NP, zinc oxide nanoparticles; TiO₂ NP, titanium dioxide nanoparticles; GO, graphene oxide