Biphasic impacts of graphite-derived engineering carbon-based nanomaterials on plant performance:Effectiveness vs.nanotoxicity

Graphite-derived carbon-based nanomaterials(GCNMs)as an exciting class of engineering carbonmaterials have been extensively exploited in environment and agriculture for pollution restorer,environmental purifier,plant growth stimulant,and stress resistance inducer.With the increasing demand of production in past decades,GCNMs were inevitably released into the natural environment and became emerging pollutants.This review briefly summarized the recent progress on GCNMs-plant interaction with positive and negative sides,and discussed the biphasic(stimulatory-inhibitory)regulation of GCNMs on plant systems.The emphasis was placed on disseminating the latest scientific research,covering various effectiveness of GCNMs on plants and cells as well as nanotoxicity.Particularly,it is highlighted that fullerenes,carbon nanotubes,graphenes,and their functionalized forms as the representative zero-,one-,and two-dimensional GCNMs in optimum quantity have favorable efficacy on plants for seed germination,growth and development,fruit and productivity,and stress tolerance.On the contrary,GCNMs have possibly induced cytotoxicity and phytotoxicity on plant at anatomic,physiological,and genetic levels.The toxic mechanisms were mainly attributed to ion leakage from membrane,chloroplast damage,decreasing the levels of photosynthetic/nonphotosynthetic pigments and plant hormones,downregulating activities of metabolism and enzymatic/non-enzymatic antioxidant systems,or triggering ROS increase for inducing oxidative stress.This comprehensive review provides an in-depth insight of advanced progress made toward the utilization of GCNMs in plant science fields as well as current challenges.Future perspectives on a directional guide for further research in the emerging area of GCNMs-enabled phytonanotechnology are summarized at the end.This will possibly provide an important reference role for further study and rational application of GCNMs in agriculture.

Adenovirus-mediated tissue inhibitor of metalloproteinase-3 gene transfection inhibits rabbit intervertebral disc degeneration in vivo

The aim of this study was to investigate the inhibitory effects of recombinant adenovirus vector carrying tissue inhibitor of metalloproteinase-3(RAd-TIMP-3)against degeneration of rabbit intervertebral disc.Thirty Japanese white rabbits of 4 months old were randomly divided into 5 groups.Mild or moderate rabbit lumbar disc degeneration model was constructed with the controllable axial loading device by imposing 98 N pressure at the discs for 2 weeks.Various doses of virus were injected into the degenerated discs as follows:20μL of normal saline in group 1;20μL of RAd66(an empty adenovirus vector,1.0�1010 OPU/mL)in group 2;and 20,10,and 5μL of RAdTIMP-3(1.0�1010 OPU/mL)in groups 3,4,and 5,respectively.Two weeks after the injection,the discs were collected for investigations,including assessment of degeneration degrees according to the Thompson’s grading system,reverse-transcription polymerase chain reaction(RT-PCR)assay for TIMP-3 gene,Safranin O-Fast green staining,and immunohisto-chemical staining for TIMP-3 and type II collagen.According to Thompson’s criteria,the degeneration of groups 3,4,and 5,especially group 3,was alleviated as compared with groups 1 and 2.RT-PCR revealed that the expression of TIMP-3 in groups 3,4,and 5,especially in group 3,was significantly enhanced as compared with group 1(P<0.01).Both Safranin O-Fast green staining and type II collagen staining demonstrated better reserved integrity of disc matrix in groups 3,4,and 5 than in groups 1 and 2.TIMP-3 staining exhibited an obvious increase of positive-staining rate in groups 3,4,and 5 as compared with group 1.The positive-staining rate in group 3(79.42%�1.35%)was about 3 times that of group 1(25.47%�5.46%,P<0.01).RAdTIMP-3 can effectively protect the matrix of rabbit intervertebral disc against overloading-induced degeneration in a dose-dependent manner,resulting in the alleviation of disc degeneration.