Research On The Aggregation Of Chloroplast Caused By Nanoparticles

Carbon nanotubes is a typical one-dimensional nano-material, the unique structuralcharacteristics, excellent physical and chemical properties make CNTs have broadapplications in many fields such as physical, chemical and biological sensors. With the wideapplication of CNTs, more and more people are concerned with its potential risk on plants,animals, human health and environment. Many studies have shown that CNTs have sometoxic effects. CNTs will not only lead to cytotoxicity, but also produce organ damage andgenetic effects. Chloroplast is the main carrier of plant photosynthesis which will be greatlyaffected by the distribution of chloroplast. Although a growing number of researchers areinvolved in the study of the toxicity of CNTs, more and more results have been reported. Butno research on the change of chloroplast distribution caused by CNTs has been seen.This paper mainly studies the effects of multi-wall carbon nanotubes (MWCNTs) on thedistribution of chloroplast in Aloe Vera cells. Aloe protoplasts were obtained by enzymolysisand the activity of the purified protoplasts was detected by staining method. Protoplasts withgood activity were used in subsequent experiments. MWCNTs were also purified to removeresidual impurities. The degree of the aggregation of chloroplast caused by MWCNTs wascharacterized using grid-counting procedure. The aloe protoplasts treated only with DI waterwere used as control. Experimental results showed that, after co-cultured with MWCNTs, theaggregation degree of chloroplast increased gradually, and then the cell ruptured and dead.Compared with the control, cultured under the same conditions, MWCNTs treatment couldobviously accelerate the aggregation of chloroplast, and shorten the life of protoplasts. Theresults also showed that the effects of MWCNTs on the distribution of chloroplast wereconcentration dependent. Within a certain range of concentrations, the chloroplasts’aggregation increased with the increase of the concentration of MWCNTs. MWCNTs withsmaller diameter has greater influence than that with larger diameter MWCNTs. Ourresearches revealed the effects of MWCNTs on plant cells from a new perspective, andwould be helpful to the comprehensive understanding of the mechanism of the interactionbetween MWCNTs and plant cell, especially the effect of MWCNTs on the photosynthesisof plants.