Effect Of Water Change On Plant Enzyme Activities In Typical Frozen Soil Region Of Xiaoxing 'an Mountains

In this paper,the effects of water conditions on antioxidant enzymes and anaerobic respiration enzyme activities of plants were discussed and studied by field sampling and in-situ flooding experiments of three typical vegetation in typical frozen regions,Betula platyphylla Suk,Vaccinium uliginosum L and Carex spp.,in the Great Xingan Mountains and the Lesser Khingan Mountains?The content of malondialdehyde(MDA),the activities of antioxidant enzymes(SOD,POD,CAT)and anaerobic respiratory enzymes(PDC,ADH,LDH)were determined by enzyme linked immunosorbent assay(ELISA).Correlation analysis was used to explore the influence of water status on the changes of plant enzyme activity,Mann-Kendall mutation test was used to study the change trend of plant enzyme activity under flooding stress,and multiple regression analysis was used to predict plant enzyme activity.The conclusions are as follows.(1)The influence of water condition on plant enzyme activityIn the field sample,the soil moisture of Heihe was 20%-40%,Wuyiling 40%-60%and Huzhong 60%-80%,respectively.Carex japonicus is most suitable to grow in the soil moisture range of 40%-60% in Heihe,60%-80% in Wuyiling and 40%-60% in Huzhong.Beyond the suitable growth range,malondialdehyde content hormone increased.With the increase of soil moisture,the changes of enzyme activities in different plants were very different.However,in the flooding experiment,the antioxidant enzyme activities of Betula platyphylla and Bog bilberry increased first and then decreased,while that of carex decreased first and then increased.The anaerobic respiration enzyme activities of betula platyphylla,Cranberry and carex grass increased and then decreased.In the field sampling results,the changes of SOD and cat activities of Betula platyphylla were consistent,while the changes of PDC and ADH activities were opposite;The activities of pod and cat were consistent,the activities of SOD were opposite,and the changes of PDC and ADH activities were consistent;The changes of SOD and POD activities of Carex were opposite.In the flooding experiment,the overall change law of antioxidant enzyme activity was first increased and then decreased.(2)Study on the changing trend of plant enzyme activities under waterlogging stressUnder flooding stress,the changes of enzyme activities of betula platyphylla,Bog bilberry and carex grass showed significant mutation points,namely inflection points,and the rules were as follows: With the increase of flooding stress,the inflection point of SOD enzyme activity was advanced,POD enzyme activity inflection point was advanced,CAT enzyme activity inflection point was advanced,PDC enzyme activity inflection point was advanced,ADH enzyme activity inflection point was advanced,LDH enzyme activity inflection point was advanced.(3)Plant enzyme activity prediction.The distribution of enzyme activities in different plants was predicted by multiple regression analysis.The distribution of enzyme activities of Betula platyphylla and bilberry is very similar.The distribution laws of SOD,cat and ADH enzyme activities are Wuyiling > Heihe > Huzhong.The distribution of SOD activity in Carex is the same as that in the other two plants,while the distribution of cat and ADH activity is opposite to that in the other two plants.