Mechanism Of Hydrogen Rich Water (HRW) Alleviating Cadmium Stress On Rice

The effect of different hydrogen rich water treatment on physiological and biochemical indexes of rice under cadmium stress is mainly studied in this paper.The purpose is to explore whether the hydrogen rich water can alleviate the toxicity of cadmium to rice.In order to achieve this goal,experiments were carried out in combination of solution culture and soil culture.The hydroponic experiment mainly designed 8 groups,which are:(1)HRW culture +Cd,2 HRW culture-Cd,(3)nutrient solution culture +Cd,4 nutrient solution culture-Cd,5 leaf spraying HRW+Cd,6 leaf spraying HRW-Cd,7 distilled water spraying + Cd,distilled water spraying-Cd,the main research is the hydrogen rich water treatment on the hydroponic rice ground part and root The effects of biomass,cadmium content,root length and plant height,and antioxidant enzyme activities(SOD,POD,CAT)were also studied.The soil culture experiment mainly designed 6 groups,which are: 1,water spray water on the leaf surface,water irrigation 2,water spraying water on the leaf surface,water irrigation 3,spraying tap water on the leaf surface,water irrigation 4,water spraying tap water on the leaf surface,hydrogen water irrigation 5,water on the pot bottom irrigation,the leaf surface without 6,the rich water of the pot bottom,no spray on the leaf surface,and the main research of the rich hydrogen water.The effects of cadmium on the growth and development of rice,the remission of cadmium concentration in root,stem and leaf and rice,as well as the activity of antioxidant enzymes in the roots and stem and leaves of rice.Finally,the following conclusions are drawn.(1)In hydroponic experiment,the fresh weight of rice root in the root of rice with hydrogen rich water is higher than that of hydrogen rich water.The fresh reuse of hydrogen rich water in the stem and leaf to spray the leaf surface is higher than that of the water.It shows that the hydrogen rich water can increase the biomass of rice under the toxicity of cadmium.(2)In the hydroponic experiment,the cadmium content in the roots and the stems and leaves of the rice treated with cadmium rich water is lower than that in the nutrient solution.The cadmium content in the roots and stems of the rice on the leaf surface is lower than that of the foliage spraying with the clear water leaf.With the lowest cadmium content,the cadmium content in the stems and leaves of the rice is the lowest with the hydrogen rich water foliage.For soil culture,irrigation with hydrogen rich water or foliar spraying can reduce the cadmium content in rice roots,stems and leaves and rice,especially with hydrogen rich water for irrigation and spraying with hydrogen rich water at the same time.The effect is more obvious.The cadmium in roots,stems and leaves and rice decreased by 8%,10% and 10% compared with the control.It indicates that hydrogen rich water can reduce the uptake of cadmium by roots and decrease the transport coefficient of roots to stems and leaves.This is probably because the hydrogen rich water rebuilt the redox balance,inhibited the production of ROS,and reduced the toxicity of cadmium.(3)In the hydroponic experiment,in the treatment of cadmium,the root and plant height of treatment 5(foliar spraying of hydrogen rich water + cadmium)is higher than that of other treatments.It shows that spraying rich water on the leaf surface has a more significant effect on the growth and development of rice,followed by the application of hydrogen rich water for foliar spraying,and irrigation with hydrogen rich water in soil culture experiment.Increasing the root length of rice obviously and spraying the leaf surface with the hydrogen rich water can obviously alleviate the small symptom of the dwarf stem and leaf caused by the cadmium toxicity,and make the stem and leaf become more and more heavy.After treatment with hydrogen rich water,the seed setting rate of rice increased,and the yield increased.This is mainly manifested in the rice and rice weight.The results showed that the application of hydrogen rich water to the leaf surface spraying with hydrogen rich water was better for the growth and development of rice,and more significant for the mitigation of cadmium toxicity.(4)In hydroponic experiment,the activity of antioxidant enzymes(APX,SOD,POD)of rice roots and stems and leaves was measured,and the results showed that the activities of POD,SOD and CAT in the roots and stems of rice treated with hydrogen rich water were higher than those of the control group,and the hydrogen rich water was used in the soil culture experiment.Row irrigation or foliar spraying can increase the antioxidant enzyme activity of cadmium poisoning rice,mainly including PODandCAT.Hydrogen rich water was used to improve the activity of antioxidant enzyme in foliar spraying with water rich water at the same time.It showed that the hydrogen rich water could improve the activity of antioxidant enzymes and alleviate the oxidative damage.(5)In soil culture experiments,by measuring the physical and chemical properties of the soil before and after the harvest,it is concluded that the content of cadmium in the soil irrigated by hydrogen rich water is more than that of the control,indicating that the cadmium absorbed by the root is relatively less,that is to say that the irrigation of the rich water prevents the transport of cadmium from the soil to the root.