Research On The Anti-sulfur Metabolic Mechanism Of Purui Poplar

Sulfur dioxide is one of the most common polluting gases.Useing plants for the absorption and conversion of atmospheric pollutants is an important measure in the treatment of atmospheric pollution.It represents one the hot spots for the study of ecological civilization construction and environmental governance in China.The poplar variety ‘Purui'(Populus × euramericana CV.“Purui”),a poplar-tolerant variety,was naturally selected in a sulfur dioxide-contaminated environment.New varieties of poplar with anti-sulphur characteristics may play an important role in the control of sulfur dioxide pollution.This study simulates the atmospheric sulfur dioxide pollution test by using a self-made dynamic smoke system.The experiment setted up different sulfur dioxide fumigation concentration(CK,0.7ppm,1.4ppm,2.6ppm).In this paper,we analyzed the changes of physiological and biochemical indexes of the ‘Purui' poplar and ordinary 107 variety(Populus × euramericana CV.“74/76”)in different degrees of sulfur dioxide stress.Simultaneously,we analyzed the changes of the expanding leaves and the fully developed leaves.We measured the content of sulfate accumulation,glutathione(GSH)and cysteine(Cy S),the activity of sulfite oxidase(SO),adenosine 5'-phosphosulfate reductase(APR),sulfite reductase(Si R),serine acetyltransferase(SAT)and O-acetylserine(thiol)lyase(OAS-TL).The results read as follows.1.In this test,we analyzed the changes of physiological and biochemical indexes of the ‘Purui' poplar and 107 poplar in the same sulphur dioxide fumigation concentration to further study the ability of ‘Purui' poplar to absorb,assimilate,and convert SO2.The results of this study show :for the expanding leaves,the content of “Purui” poplar of sulfate accumulation and glutathione,the activities of SO,APR,Si R and OAS-TL are Significantly higher than 107 poplar.For the fully developed leaves,only the activity of SO shows different patterns with the expanding leaves-no significant difference between “Purui” poplar and 107 poplar.When the plant is exposed to sulfur dioxide stress,the plant can initiate oxidative detoxification pathways,that is,increase SO activity,oxidize excess toxic sulfite to non-toxic sulphate storage,or perform sulphur assimilation pathway to synthesize some compounds like GSH.“Purui” poplar and 107 poplar can through the oxidation pathway to relieve stress damage,but “Purui” poplar's ability is much higher than the 107 poplar.Plants can also through an assimilation pathway to relieve stress damage,that is,increase APR activity to promote the synthesis of sulfur compounds.In this study we know that the SO and APR are the key enzyme to detoxification strategies for plants.2.By comparing the changes of physiological and biochemical indexes in the expanding leaves and the fully developed leaves of the same plant under the same sulfur dioxide fumigation stress,we can leaen the reason why the expanding leaves have more resistance to sulfur dioxide than the fully developed leaves.For the “Purui” poplar,the content of sulfate accumulation and glutathione,the activities of SO,APR in the expanding leaves are significant difference than the fully developed leaves.For the 107 popar the content of sulfate accumulation and glutathione,the activities of SO,APR and OAS-TL in the expanding leaves are significant difference than the fully developed leaves.So,for the expanding leaves,SO and APR are the key enzyme to detoxification strategies.