Fig. 4

MWCNT-induced LR formation was sensitive to the removal of endogenous NO with cPTIO, its scavenger. Three-day-old tomato seedlings were treated with distilled water, 5 mg/mL MWCNT, 0.1 mM SNP, 0.2 mM cPTIO, alone or in combination for 3 days. Afterwards, the number and length of emerged lateral root (> 1 mm) per seedling were then determined. There were 30 (10 × 3) plants in three biological replicates, and the experiments were conducted for 3 times. Data are the means ± SE. Within each set of experiments, bars denoted by the same letter did not differ significantly at p < 0.05 level according to Duncan’s multiple test