Effect Of Arsenic Subcellular Distribution And Non-protein Thiols Of Root On Translocation In Wheat(Triticum Aestivum L.)

Arsenic(As)is a well-known poisonous metalloid element that is ranked first by the Agency for Toxic Substances and Disease Registry(ATSDR).The enriched arsenic may enter human body through the food chain,causing various diseases and great threat to human health.The study on the method of alleviating the arsenic toxicity in wheat(Triticum aestivum L.)is of great significance to reduce the risk of food safety caused by arsenic pollution.In the present study,three wheat cultivars(Jinmai 85,Qingfeng 1 and Jining 12)that have different arsenic tolerance were used to investigate the relationship between arsenic subcellular distribution and non-protein thiols complex with translocation in wheat.In the study,I was used hydroponic and soil culture method combines subcellular fractionation and UPLC techniques.The aim of the study is to explore arsenic resistance mechanism in root.The results showed that the arsenic concentration of different length root in JM85 is higher than other two wheat cultivars after treated by 10 ?mol L-1 As(?),and the higher As content in the farther root segment away from the root tips.Different root arsenic content in different wheat cultivars,and in wheat roots the same species of arsenic subcellular components also has significant differences.The As concentration of subcellular in JM85 are higher than Qingfeng1 and Jining12 of seedling stage,tilering stage or elongation stage that treated by 10 ?mol L-1 As(?),and the As concentration regular pattern is:Soluble cytosol>Cell wall>Organelle fragment.Absorbed into the roots of As(V)rapidly reduced to As(?),and As(?)with some complex compound containing a thiol group,common small molecule non-protein thiols is Phytochelatins(PCs).Applying y-glutamylcysteine synthetase inhibitor,L-Buthionine-sulfoximine(BSO),the roles of PCs in As tolerance and accumulation in were evaluated.The soil culture results showed that BSO could promote the translocation of arsenic to shoot or grain,PCs significantly inhibited the translocation of arsenic to shoot,and the flag leaves played an important role in the process of grain transport.It showed that the As-PCs complex content in roots of JM85 more than the other two cultivars obviously.Different wheat cultivars have significant differences in As accumulation,translocation and tolerance.And the As transloation factors of JM85 is lower than QF1 and JN12,the As tolerance index is the opposite.It showed that the mechanism of arsenic tolerance may closely related to the interaction of the soluble cytoplasmic region and the complexation of thiol compounds.