Research On Isolation Of 69.5kD Heat-stable Protein In Zea Mays Seedling Roots Under Different Stress And Its Expression Regulation

The maize variety (Zea mays) of stress-resistance 'LuDan 9002'was cultivated by Hoagland solution and treated with drought, high-salt, low and high temperature stresses. The whole soluble proteins in maize seedling roots were extracted and detected by SDS-PAGE . In contrast to untreated, a novel heat-stable protein was found, and its molecular weight was measured. Then treated with more cross stresses, detected changes of its expression content in order to illuminate the mechanism of systemic resisitance and cross adaptation response to different stresses. Furthermore, some hormone and signal transfer substances were inflicted on maize seedling roots to analyze the expression and regulation on the novel heat-stable protein. The main results were as follows: 1. The heat-stable protein was extracted in different stresses. Fistly, the treated maize seedling roots were ground with fine powder in liquid Nitrogen, and extracted for 20min at 4℃by 1.5:2 volumes of extraction buffer , then centrifuged at 10,000g for 20min at 4℃. The supernatant was heated in 80℃water bath for 10min, centrifuged at 6,000g, for 10min at 4℃. Finally, the supernatant containing whole heat-stable proteins were precipitated by freezing acetone, then centrifuged, the precipitates was redissolved in sample butter, after centrifuged, the supernatant were detected by 13% SDS-PAGE. 2.The novel heat-stable protein was found. After SDS-PAGE , in contrast to untreated,a novel protein with about 69.5kDa-MW was always expressed , and its content was somewhat high in the whole soluble proteins . The novel protein was heat-stable and still expressed when removed the...