Study On The Effects Of Compounds On Redox Potential Of Plant Root Cells Based On Ro-GFP Fluorescence Probe

The redox-sensitive green fluorescent protein probe（ro GFP）has become a means to assess the average state of redox in living cells.Ro GFP has been widely used in plants to detect the redox levels because of their non-destructive,localized,reversible,real-time and dynamic advantages.Due to the ro GFP in the mitochondria（mitochondria-ro GFP,m-ro GFP）is more capable for reflecting redox potential than the ro GFP in the cytoplasm（cytoplasm-ro GFP,c-ro GFP）,this paper uses m-ro GFP Arabidopsis to determine the redox potential of root tips for several representative commercial herbicides and natural herbicides such as berberine and its analogues.It will establish a rapid and micro-screening method for the study of natural compounds and to provide a theoretical basis for their target research.The main research results are as follows:（1）Amino acid biosynthesis inhibitors（glyphosate and glufosinate-ammonium）and microtubule inhibitors（pendimethalin and trifluralin）both have an effect on the redox potential of the Arabidopsis root tips.The redox potential meet the minimum in the proximal meristem,and gradually became more oxidized from the transition zone,reached the maximum in the elongation zone.After treatment with glyphosate,glufosinate-ammonium,pendimethalin,and trifluralin,the redox potential potential changes from-351.82 m V～-334.48 m V,-308.04 m V～-291.42 m V,-320.24 m V～-342.85 m V and-357.08 m V～-339.95 m V.The maximum redox potential changes were 29.68 m V,20.43m V,6.55 m V and 14.36 m V,respectively.（2）The redox potential photosynthesis photosystem II inhibitors（atrazine and hexazinone）show regularity,reaching the minimum redox potential at a distance of 100μm to 200μm（proximal meristem）from the root tip.The redox potential reaches the maximum the elongation zone starting from the proximal meristem with the tendency of being gradually oxidized.After the treatment of atrazine,the minimum redox potential in the proximal meristem was-360.72 m V,followed by the root cap potential was-345.70 m V,and the transition zone potential was-335.48 m V,reaching the maximum potential value in the elongation zone.After the treatment with hexazinone,the minimum redox potential value was-356.23 m V in the proximal meristem,the potential in the root cap was-341.59m V,and the potential in the transition zone was-329.06 m V,reached maximum potential was-319.47 m V in the elongation zone.All results indicated that the m-ro GFP fluorescent probe can better respond to photosystem II inhibitors.（3）The effect of glyphosate on the redox potential and its change of Arabidopsis root cells has a significant dose-effect relationship.The redox potential changes of glyphosate at10 mg·L^-1was 20.19 m V～27.66 m V,at 20 mg·L^-1 was 23.29 m V～30.21 m V;at 50mg·L^-1was 24.29 m V～46.01 m V.As the concentration increases,the change of the redox potential increases gradually,showing a positive correlation.The correlation coefficient R²is 0.9956.（4）Berberine and its analogues have an effect on the redox potential of Arabidopsis root tips.The results showed that the redox potential of sanguinarium chloride,chelidonine,（R）-（+）-corypalmine,rotundine and dihydroberberine have a significant differences.There are also have significant differences on the redox potential of each compounds treatment in proximal meristem.The results indicated that the proximal meristem should be used as the main observation area to determine the redox potential.（5）It was found that 2 structural analogues worenine chloride and coptisine chloride have a obvious herbicidal activity.The inhibition rates of the total chlorophyll of worenine chloride and coptisine chloride on Lemna minor were 80.34%and 77.21%.The maximum inhibition rates of fresh weight of worenine chloride and coptisine chloride on Ageratum conyzoides were 97.71%and 100%.The inhibition rates of primary root length of 2 agents on A.conyzoides were 100%.The maximum inhibition rates of fresh weight of worenine chloride and coptisine chloride on Mikania micrantha were 98.43%and 99.08%.The inhibition rates of primary root length on M.micrantha of 2 agents were 100%.All results indicated that worenine chloride and coptisine chloride can be used for the herbicides on L.minor,and invading weeds A.conyzoides and M.micrantha.At 28 days,100 mg·L^-1 of the compound has significant herbicidal activity on Alternanthera philoxeroides.