Functional Analysis Of The Zea Mays Sulfite Oxidase Gene (ZmSO) Under Sulfur Dioxide Stress

Abstract SO2is a main atmospheric pollutant at present in China. It causes damage to crops such as maize and thus affects yield and quality in maize production. A gene encoding sulfites oxidase (ZmSO) from maize was previously cloned and its genomic and biochemical properties were charaterized in our lab. On the basis of these results, my thesis mainly focused on three aspects as follows:1. Expression patterns of ZmSO under different stress conditions in maize. Using real-time quantitative fluorescence PCR (real-time PCR) to do analysis of the expression quantity of ZmSO in corn inbred line Zheng58which was dealt with4stress conditions:high temperature, low temperature, drought and SO2stress. The results indicated that ZmSO played a role of negative regulation and its expression quantity reduced in low temperature and high temperature. And ZmSO played a role of positive regulation and its expression quantity increased in drought and SO2stress. It’s consistent that the amount of ZmSO expression increased under SO2stress and ZmSO participates in SO2detoxicification. But it still needed to explore that how ZmSO participated in the organism’s protection under drought stress.2. Analysis of ZmSO regulatory function. Firstly, ZmSO promotor(ZmSOp) sequence was obtained using bioinformatics analysis. By designing deletion fragment of different promotors, plant expression vectors of p-ZmSOp:GUS was successfully constructed. with The results of analysis indicated that the functional domain of ZmSO promoter dyed by GUS,ZmSO promoter regulatory function of between100bp and700bp finaly were identificated.3. Research of mechanism that ZmSO participated under SO2stress resistance response using arabidopsis AtSO T-DNA insert mutant. Firstly,the plant expression vector p35S-GFP-ZmSO is constructed and then converted it into wild type arabidopsis (Col) and T-DNA insert mutant atso. The transgenic Arabidopsis of ZmSO/WT, ZmSO/atso through resistance selection and molecular marker testing. The results indicated that the genetically modified strain which got less damage than check under the SO2stress showed higher resistance to SO2. Further analysis of ZmSO molecular regulation is in progress.