The dynamic changes of the activities of enzymes involving in starch biosynthesis, including ADP-glucose pyrophosphorylase (AGPase), soluble starch synthases (SSS), starch branching enzyme (SBE) and starch debranching...The dynamic changes of the activities of enzymes involving in starch biosynthesis, including ADP-glucose pyrophosphorylase (AGPase), soluble starch synthases (SSS), starch branching enzyme (SBE) and starch debranching enzymes (DBE) were studied, and changes of fine structure of amy- lopectin were characterized by isoamylase treatment during rice grain development, using trans anti-waxy gene rice plants. The relationships between the activities of those key enzymes were also analyzed. The amylose synthesis was significantly inhibited in transgenic Wanjing 9522, but the total starch content and final grain weight were less affected as compared with those of non-transgenic Wanjing 9522 rice cultivar. Analyses on the changes of activities of enzymes involving in starch bio- synthesis showed that different enzyme activities were expressed differently during rice endosperm development. Soluble starch synthase is relatively highly expressed in earlier stage of endosperm de- velopment, whilst maximal expression of granule-bound starch synthase (GBSS) occurred in mid-stage of endosperm development. No obvious differences in changes of the activities of AGPase and SBE between two rice cultivars investigated, except the DBEs. Distribution patterns of branches of amy- lopectin changed continually during the development of rice grains and varied between two rice culti- vars. It was suggested that amylopectin synthesis be prior to the synthesis of amylose and different enzymes have different roles in controlling syntheses of branches of amylopectin.展开更多
[ Objective ] The study aimed to establish an efficient method to extract RNA from cassava, and clone the core sequence d SSS II gene. [ Method ] The cassava RNA was obtained using the modified CTAB method, which was ...[ Objective ] The study aimed to establish an efficient method to extract RNA from cassava, and clone the core sequence d SSS II gene. [ Method ] The cassava RNA was obtained using the modified CTAB method, which was then reversely transefiptod into eDNA. Degenerate primers were designed based on the ho- mology property of known SSS II sequences in other plant species. A fragment was amplified with the previously mentioned eDNA as template and the degenerate primers through Polymerase Chain Reaction （PCR）. [Result] After online blasting in NCBI, the sequence was identified as the core fragment of cassava SSS I1 gene. [ Conclusion] Our research would lay the original basis for the cloning of the cassava SSS II full length cDNA sequence and construction of its anti - sense vector, which could further provide proper candidate genes for the development of starch metah）lic en^necring.展开更多
基金the National Key Research and Development Program of China(GrantNo.G199810100)
文摘The dynamic changes of the activities of enzymes involving in starch biosynthesis, including ADP-glucose pyrophosphorylase (AGPase), soluble starch synthases (SSS), starch branching enzyme (SBE) and starch debranching enzymes (DBE) were studied, and changes of fine structure of amy- lopectin were characterized by isoamylase treatment during rice grain development, using trans anti-waxy gene rice plants. The relationships between the activities of those key enzymes were also analyzed. The amylose synthesis was significantly inhibited in transgenic Wanjing 9522, but the total starch content and final grain weight were less affected as compared with those of non-transgenic Wanjing 9522 rice cultivar. Analyses on the changes of activities of enzymes involving in starch bio- synthesis showed that different enzyme activities were expressed differently during rice endosperm development. Soluble starch synthase is relatively highly expressed in earlier stage of endosperm de- velopment, whilst maximal expression of granule-bound starch synthase (GBSS) occurred in mid-stage of endosperm development. No obvious differences in changes of the activities of AGPase and SBE between two rice cultivars investigated, except the DBEs. Distribution patterns of branches of amy- lopectin changed continually during the development of rice grains and varied between two rice culti- vars. It was suggested that amylopectin synthesis be prior to the synthesis of amylose and different enzymes have different roles in controlling syntheses of branches of amylopectin.
基金Supported by Special Fund for Agricultural Comprehensive Development of Ministry of Agriculture(Agricultural Reclamation[2010]No.23)
文摘[ Objective ] The study aimed to establish an efficient method to extract RNA from cassava, and clone the core sequence d SSS II gene. [ Method ] The cassava RNA was obtained using the modified CTAB method, which was then reversely transefiptod into eDNA. Degenerate primers were designed based on the ho- mology property of known SSS II sequences in other plant species. A fragment was amplified with the previously mentioned eDNA as template and the degenerate primers through Polymerase Chain Reaction （PCR）. [Result] After online blasting in NCBI, the sequence was identified as the core fragment of cassava SSS I1 gene. [ Conclusion] Our research would lay the original basis for the cloning of the cassava SSS II full length cDNA sequence and construction of its anti - sense vector, which could further provide proper candidate genes for the development of starch metah）lic en^necring.
