Involvement Of ROS In Promoting Maize Root Extension And Improving Drought Resistance With New Carbon Nanomaterials

In recent years,with the continuous development of nanotechnology,many researchers at home and abroad have shifted their attention to nanomaterials.It has been found that nanomaterials can regulate and promote plant growth.Our previous study found that after a certain concentration of fullerene treated maize,It could promote the germination,early growth and biomass accumulation of maize seeds,and the drought resistance of fullerene treatment was obviously improved under drought stress.A large number of studies have shown that ROS can act as a stress signal,participate in plant growth regulation and play an important role in plant root growth.It may be related to the change of ROS content and distribution in the root tip,but the mechanism is not clear.In this study,the seeds and seedlings of maize and model plant Arabidopsis thaliana were treated under different conditions with a certain concentration of fullerene.The length of phenotypic roots of the two plants and the activity of related enzymes at physiological level were measured.The experimental results are as follows:(1)Effect of fullerene treatment on the root phenotype of maize and Arabidopsis under different conditionsThe root system of maize cultured with fullerene solution of 50ug/ml in normal condition was longer than that of control.The results showed that the effect of root elongation was still obvious under the condition of 5%PEG drought stress.We treated maize with different concentrations of 0ug/ml,50ug/ml and 80ug/ml.Under8 m MH2O2 conditions,we found that under these conditions,the root length of maize cultured with 50ug/ml land 80ug/ml fullerene was longer than that of the control group,under normal conditions and hydrogen peroxide treatment,the biomass of maize treated with different concentrations of fullerenes was also significantly different from that of the control.The Arabidopsis thaliana was grown on normal MS fullerene-free MS medium for 6 days and then transferred to MS medium containing various concentrations(0 ?g/ml,20 ?g/ml,30 ?g/ml)of fullerene.Hydrogen peroxidewith a final concentration of 1 m M was applied to the culture medium.The phenotype of Arabidopsis thaliana was observed every 24 hours,the root length was measured,and the root elongation difference was calculated every 24 hours..It was preliminarily concluded that fullerene may be related to ROS in promoting maize root elongation.(2)Effect of fullerene treatment on physiology of maize and Arabidopsis thaliana under different conditionsUnder normal condition and simulated drought stress with 5%PEG6000,the activity of POD,CAT,APX in maize roots treated with different concentrations of(0ug/ml and 50ug/ml)fullerene was found to be increasing compared with that of control.The content of H2O2 was lower than that of control.Under normal conditions and under 50 m M mannitol drought stress,the roots of Arabidopsis thaliana were treated with different concentrations of(0ug/ml 10ug/ml and/ 20ug/ml)fullerene for 8days.The root system of Arabidopsis thaliana was stained with DAB solution.The results showed that the root color of Arabidopsis thaliana was lighter under the concentration of 10ug/ml and 20ug/ml.The color of Arabidopsis thaliana roots was the lightest under the treatment of 20ug/ml concentration.The experimental result suggested that the phenomenon that fullerene could promote the elongation of plant roots may increase the activity of some protective enzymes in the plant,thus enhancing the drought resistance of the plant itself and changing the plant content of ROS at the same time.,and the change of ROS were closely related to the concentration of fullerene.