在環境和氧化逆境中，植物透過生化和生理的機制來保護細胞而免於傷害。比如像超氧歧化?（superoxide dismutase；SOD）這一抗氧化機制中，超氧歧化?可以將超氧自由基（·O2－）清除而保護植物細胞而不受傷害。這就是一類典型的防禦逆境傷害的抗氧化機制。 在本研究中，使用一水溶性的自由基誘導物 [2,2'-Azobis (2-amidinopropane) hydrochloride]（AAPH）來誘發逆境氧化的產生，然後探討逆境生成時大豆在基因 (sod) 表現的變化。應用cytosolic Cu/Zn sod基因的探針來探討基因的表現情形，然後再測定超氧歧化?活性和活性電泳來了解其間的相關性。 從本研究之結果得知cytosolic Cu/Zn sod基因的表現會受AAPH刺激後而降低，但其活性會有升高的情況。根據1996年Pitcher和Zilinskas的報導指出cytosolic Cu/Zn sod對臭氧有較明顯的變化，從本試驗結果指示AAPH可能可以當作一誘發環境逆境的有利研究之工具，來替代如臭氧及其他環境因子壓力的實驗來模擬逆境之研究。 Under environmental and oxidative stress, plants can protect themselves from cellular injury. For instance, through biochemical and physiological mechanisms. Superoxide dismutase (SOD) is one of antioxidative mechanism which can be involved in scavenging the superoxide free radicals and preventing plant cells from injury. This is a typical type of an antioxidative mechanism for defending the environmental stress. In this study, a water soluble free radical initiator [2,2'-azobis (2-amidinopropane) dihydrochloride ] AAPH was used as a research tool to induce stress, and to investigate the gene expression in soybean. Using cytosolic Cu/Zn sod gene probe showed AAPH can affect the sod gene expression and SOD activity in soybean leaves. Results showed the level of the sod transcripts decreased in response to AAPH, but the level of SOD activity increased. Followed the Pitcher and Zilinskas report in 1996, the cytosolic Cu/Zn sod gene and SOD were also responded to ozone stress. From this result suggests that AAPH could be as a research tool to study the environmental stress, to replace an expensive ozone facilities.
