Regulation Of Sucrose On Grain Filling And Expression Of Sucrose Synthase Gene In Rice Plant

For understanding the purification of Sucrose synthase, preparation of the antibody of SS and regulation of sucrose on grain filling and expression of sucrose synthase by change of sucrose in rice (Oryza saliva L.), two representative elite rice cultivars, Shanyou 63, a hybrid indica rice, and Wuyujing 3, a conventional japonica rice variety, were used. The major results were abstracted as followings:1. SS has been purified. SS has been obtained from rice grains by crude extraction, ammonium sulfate precipitation, gel filtration (SephadexG-100, Sepharose CL-6B) and ion exchange column chromatogram (DEAE-cellulose, DE-32). Purified SS, identified by HPLC and PAGE, determined for molecular weight by SDS-PAGE, having a content of 71.2% and two strips, a dark SS protein and a weak impurity, will be qualified as antigen. The enzyme, having a molecular weight, 3.8 105, consists of 4 identical subunits, each having a molecular weight, 9.5 X 10 .2. The antibody of SS was obtained by immunizing rabbit. The first, second and third immunity were though in-skin, multi-spots, interval injection, the fourth and the fifth immunity through ear vein injection. Serum was obtained by neck artery. Units determined by agar pervasion experiment were over 1:8.3. Effect of sucrose concentration on the activity of SS was investigated by spikelet-thinning and leaf-cutting during florescence. Strong and weak potential grains were obtained in 5,10,15,20,25 days, and content of sucrose, soluble sugar and starch were determined as well as SS enzyme activity. The result revealed that sucrose regulates grain filling and sucrose synthase activity.4. In order to elucidate regulation of sucrose on expression of sucrose synthase gene from protein level, Western Blotting has been carried through. Protein quantity of SS instrong and weak potential grains were studied through crude extraction, SDS-PAGE, transfer, connection of SS anti-body and goat anti-rabbit IgG-HRP, DAB coloration. The result showed that sucrose regulates expression of sucrose synthase protein.