摘要
50μmol/L 激动素(KT)处理绿豆(Phaseolus radiatus L.)黄化子叶12小时可显著增加其多聚核糖体水平,并使总核糖体水平提高60%以上;KT的这种作用可被放线菌素D(ACTD)抑制。进一步测定表明,KT处理子叶12小时可显著促进RNA合成,使总RNA含量增加30%左右。其中,poly(A)^+-mRNA增加了1.2倍,25S rRNA、18S rRNA和4—5S RNA含量也有不同程度的增加。这些结果表明,KT既可促进单核糖体和核糖体亚单位形成多聚核糖体;又有促进核糖体构建的作用;KT促进多聚核糖体的形成可能依赖于mRNA新合成的增加。
The relative levels of polyribosomes and total ribosomal materials,the rates of RNA synthesis and the contents of each RNA component were investigated in excised cotyledons of mung bean (Phaseolus radiatus L.) incubated with and without kinetin.12 h incubation with 50 μmol/ L kinetin markedly increased the levels of polyribosomes and decreased the levels of monoribosome, especially of the ribosomal subunits.In addition,levels of total ribosomal materials (ribosomal subunit+monoribosome+polyribosome) were also increased in cotyledons incubated with kinetin.The kinetin-promoted polyribosome formation could be arrested by the RNA synthesis inhibitor——actinomycin D(ACTD).Kinetin incubation greatly enhanced RNA synthesis and in creased that RNA conten.A marked increase was found in the amount of poly(A)^+-mRNA, while the levels of other RNA components (25S,18S rRNA,4-5S RNA) were also increased to different extent.These results suggest that the promotion of polyribosome formation by hinetin depends upon the de novo synthesis of mRNAs,and the promotion of ribosome construction by kinetin may also be related to the synthesis of rRNAs.
基金
国家教委博士学科点专项科研基金资助课题
关键词
激动素
RNA合成
绿豆
多聚核糖体
Phaseolus radiatus
Kinetin
Polyribosome formation
RNA synthesis
