The Physiological And Biochemical Response Of Buckwheat Seedlings To Lead&Aluminum Stress And Rectification Of Its Toxicity

Experimented on over20Jiujiang buckwheat materials, the growth ofroot system under lead and aluminum stress of different concentration isstudied on and the buckwheat materials with high lead and aluminumstress and low resistance are sifted from the subjects. Based on the study,this paper explores the damage mechanism of lead and aluminum stressupon buckwheat, detoxification mechanism of buckwheat under lead andaluminum stress and damage alleviation mechanism of differentexogenous additives upon buckwheat under lead and aluminum stress.Research results further confirm that lead and aluminum stress haveplayed an important role in the growth of buckwheat and laid a significantfoundation for pollution-free production of buckwheat. The main findingsare listed as follows:1. The sifting of buckwheat materials with lead and aluminumresistance.Experimented on20buckwheat materials and based on thestudy on the growth of root system under the lead and aluminum stress ofdifferent concentration, the buckwheat L2081with strong lead andaluminum resistance, T370with weak lead resistance and T454withweak aluminum resistance are sifted from all the subjects.2. The research on the physiological and biomedical indexes ofbuckwheat under lead and aluminum stress.2.1The lead and aluminum stress of low concentration can lead to the decrease of membrane permeability and proline of L2081while the highconcentration leads to the increase of these two indexes. With the increaseof the concentration of stress, the content of Chlorophyll rises first andthen falls down. There are differentiation among different species. Themembrane permeability, proline and superoxide anion free radical contentin T454and T370are higher than those in L2081. And the content ofChlorophyll and root activity in T454and T370are lower than that inL2081. It shows that L2081is more aluminum resistant than T454andmore lead resistant than T370.2.2DNA cross-linking: with the increase of lead and aluminum stressconcentration, hyperchromic effect of DNA in buckwheat leaves issignificantly reduced. Under lead stress, buckwheat L2081is higher thanT370. Under aluminum stress, buckwheat L2081is higher than T454.3. The research on the resistance of buckwheat under lead andaluminum stress.The lead and aluminum stress of low concentration can promote theactivity of SOD, POD and CAT. The achieve their maximum value whenthe concentration of lead and aluminum stress is50μmol·L-1. And thenthey will decrease with the increase of the lead and aluminum stressconcentration. Their differentiations are prominent with differentconcentration treatment. Among different species, the activity of SOD,POD and CAT in L2081are higher than that in T454and T370. 4. The research on damage alleviation mechanism of buckwheatunder lead and aluminum stress with different additives.4.1Different concentrations of citric acid can alleviate the damage ofbuckwheat under aluminum stress to a certain extent. It can be seen fromfollowing aspects: with the increase of the concentration of citric acid, thecontent of MDA, proline and superoxide anion free radical in buckwheatmaterials are prominently reduced; The chlorophyll content and rootactivity rise significantly with the increase of the concentration of citricacid; With the increase of the concentration of citric acid, the activity ofSOD, POD and CAT in two buckwheat leaves increase significantly.Exogenous citric acid can significantly increase the DNA hyperchromiceffect of buckwheat leaves. They are various among different species.The DNA hyperchromic effect in L2081is more prominent than that inT454. Citric acid significantly inhibit buckwheat from the absorption ofaluminum under aluminum stress. It differentiate in aluminum absorptionability between different parts of buckwheat which is: root> stem> leaf.4.2Different concentrations of CaCl2treatment can alleviate the damageof buckwheat under aluminum stress to a certain stress. With theincrease of the concentration of CaCl2, the content of MDA, proline andsuperoxide anion free radical in buckwheat materials are prominentlyreduced; The chlorophyll content and root activity rise significantly withthe increase of the concentration of CaCl2; With the increase of the concentration of CaCl2, the activity of SOD, POD and CAT in twobuckwheat leaves increase significantly. Exogenous citric acid cansignificantly increase the DNA hyperchromic effect of buckwheat leaves.They are various among different species. The DNA hyperchromic effectin L2081is more prominent than that in T454. CaCl2significantly inhibitbuckwheat from the absorption of aluminum under aluminum stress. Itdifferentiate in aluminum absorption ability between different parts ofbuckwheat which is: root> stem> leaf.4.3Different concentrations of salicylic acid treatment can alleviate thedamage of buckwheat under aluminum stress to a certain stress. Withthe increase of the concentration of salicylic acid, the content of MDA,proline and superoxide anion free radical in buckwheat materials areprominently reduced; The chlorophyll content and root activity risesignificantly with the increase of the concentration of salicylic acid; Withthe increase of the concentration of salicylic acid, the activity of SOD,POD and CAT in two buckwheat leaves increase significantly. Exogenouscitric acid can significantly increase the DNA hyperchromic effect ofbuckwheat leaves. They are various among different species. The DNAhyperchromic effect in L2081is more prominent than that in T370.Salicylic acid significantly inhibit buckwheat from the absorption ofaluminum under aluminum stress.