The Effect Of BPA On Mineral Elements Contents And Ativities Of Respiratory Enzymes In Soybean Roots

Environmental endocrine disruptor-bisphenol A(BPA) is an important raw material. Due to the widespread use of BPA in daily life and production, this chemical has become ubiquitous in the environment. In the study, the effects of BPA(1.5 mg·L-1, 3.0 mg·L-1, 6.0 mg·L-1, 12.0 mg·L-1, 24.0 mg·L-1, 48.0 mg·L-1, and 96.0 mg·L-1) on the contents of nitrate(NO3-), ammonium(NH4+), phosphorus(P), potassium(K), calcium(Ca), magnesium(Mg), iron(Fe), manganese(Mn), copper(Cu), zinc(Zn), and molybdenum(Mo), absorbing ability(root activity and absorptive area) and activities of critical respiratory enzymes [hexokinase(HK), phosphofructokinase(PFK), pyruvatekinase(PK), isocitrate dehydrogenase(ICDH) and cytochrome c oxidase(COX)] of soyben(Glycine max) roots at different growth stages were investigated by using inductively coupled plasma mass spectroscopy(ICP-MS) and some other physiological and biochemical methods. The main experment results were shown as follows:(1) Compared with the controls, BPA increased the levels of NO3-, P, K, Mg, Mn, and Mo in soybean roots at different growth stages, as well as Zn level at soybean seedling roots. Whereas, treatments with higher concentrations of BPA inhibited the levels of these mineral elements in a dose-dependent manner. All treatments with BPA caused increases in the levels of NH4+ Ca, Fe, Zn(except for seedling stage), and Cu in the roots, and greater increases were observed following treatment with higher concentrations of BPA. Following the withdrawal of BPA exposure, the mineral elements contents were recovered to some extent(seedling stage > seed filling stage > flowering and pods formation stage > mature stage) except for those treated with 48.0 mg·L-1and 96.0 mg·L-1 BPA.(2) Low concentrations of BPA increased the root activity and absorptive area, whereas, the opposite effects were existed when treated with higher concentrations of BPA, and greater decreases were observed with increasing the concentrations of BPA. In the recovery period, the indices above were recovered to some extents(seed filling stage > flowering and pods formation stage > seedling stage > mature stage) except for those treated with 48.0 mg·L-1and 96.0 mg·L-1 BPA.(3) Low concentrations of BPA increased the activities of HK, PFK, PK, ICDH and COX of soybean roots at different growth stages. Conversely, the activities decreased with increasing the concentrations of BPA and time of exposure. Following the withdrawal of BPA exposure, the recovery of activities were more obvious with lower concentrations of BPA and longer recovery time, whereas, the activities of roots treated with 48.0 mg·L-1and 96.0 mg·L-1 BPA were unrecovered.(4) Correlation analysis results indicated that contents of NO3-, P, K, Mg Mn in soybean roots were significantly positively correlated with roots activity, total absorptive area, active absorptive area, as well as activities of respiratory enzymes. Whereas, contents of NH4+, Ca, Fe, Cu and Zn were negatively correlated with those indices.In conclusion, the interference by BPA to the absorbing ability and respiration of roots, may be one of the effect mechanisms of BPA on mineral element accumulation in roots.The aim was to provide some theoretical basises for the effects of BPA on roots mineral nutrition and the effect mechanism, as well as offered some references for scientifically evaluating the effect of BPA on crop production and food safety.