Previous studies have suggested that
multiwalled carbon nanotubes
(MWCNTs) promote plant growth; however, the mechanism is yet to be
fully understood. In this study, the effects of MWCNTs (20, 100, and
500 mg/L) on the carbon (C) and nitrogen (N) metabolism in maize were
studied to explore the molecular mechanism of the action of MWCNTs
on plants. The results showed that 100 mg/L MWCNTs increased the shoot
fresh and dry weight, root fresh weight, and seedling length while
other doses showed no significant effects. Further studies showed
that 100 mg/L MWCNTs increased the chlorophyll content, transpiration
rate, stomatal conductance, and intercellular CO2 concentration,
by 50.6%, 60.8%, 47.2%, and 32.1%, respectively. Activities of key
enzymes including sucrose synthase (SS), sucrose phosphate synthase
(SPS) and phosphoenolpyruvate carboxylase (PEPC) that are involved
in the carbon metabolism, and nitrate reductase (NR), glutamine synthetase
(GS), and glutamate synthetase (GOGAT) that are involved in N metabolism,
were all upregulated by 100 mg/L MWCNTs, which contributed to the
increase of the accumulation of carbohydrates (sugar and starch),
soluble protein, and N in plants. These findings suggest that MWCNTs
can improve plant growth by regulating the key enzymes involved in
C and N metabolism thereby enhancing the carbohydrate production and
the use of N and improving plant growth. This study provides significant
insights into the molecular mechanism of the positive effects of MWCNTs
on plants and provide a basis for the agricultural application of
MWCNTs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.