作　　者： ; ; ; ; ;

机构地区： 深圳大学生命科学学院深圳市微生物基因工程重点实验室

出　　处： 《深圳大学学报（理工版）》 2013年第1期84-90,共7页

摘　　要： 为研究种子是否能完全依靠储存的mRNA或储存的蛋白质完成萌发过程,分别利用转录抑制剂α-鹅膏蕈碱(α-amanitin)和制剂放线菌酮处理大豆胚根,抑制新的mRNA或新的蛋白质的合成,观察大豆胚根的萌发情况.结果发现,在转录抑制的条件下,大豆胚根能够完成萌发,种子萌发后,种苗生长停止;在翻译被抑制的条件下,大豆胚根不能完成萌发.说明大豆胚根萌发能够依赖发育过程合成并贮存在干种子中的mRNA;但种苗的发育不能完全依赖储存的RNA,需要新合成的mRNA参与.大豆胚根不能依赖储存蛋白质完成萌发过程.对大豆胚根细胞内容物进行超速离心并对不同组分中mRNA含量进行定量分析发现,干种子中的mRNA主要存在于多核糖体之外的细胞结构中,而在萌发过程中,mRNA主要存在于多核糖体中.这表明干种子中的mRNA主要以储存状态存在于mRNA的储存结构中,萌发过程大部分mRNA从储存结构中转移到多核糖体中变为活跃的翻译状态.不同萌发时期多核糖体的特征曲线也体现mRNA在细胞内存在位置的这种变化. Although intensive studies have been conducted in seed germination, the exact requirements for germi-nation is still poorly understood, particularly in terms of de novo RNA and protein syntheses. To find out if seeds can complete germination relying solely on stored mRNAs or stored proteins, transcription inhibitor α-amanitin and translation inhibitor cycloheximide were used to inhibit the synthesis of new mRNAs and new proteins of soy-bean radicles respectively. Germination of soybean radicles were observed after these treatments. Results show that, under the conditions of inhibition of transcription, soybean radicles are able to complete germination, but seedling growth stops. Under the conditions of the inhibition of translation, soybean radicles cannot complete ger- mination. These results indicate that soybean radicle germination can rely on the mRNAs synthesized during seed development and stored in the dry seeds. The development of the seedlings cannot totally rely on stored mRNAs： newly synthesized mRNAs are required for this process. Also newly synthesized proteins are needed for soybean radicle germination. Fractionation of soybean radicle cell components by uhracentrifugation and quantification of mRNAs in different cell fractions by real-time PCR finds that mRNAs exist mainly in non-polysome structures in the dry seed while they exist mainly in the polysome after 4 hours of imbibition. This suggests that mRNAs are mainly in the state of storage in dry seeds. After imbibition, mRNAs move to polysome in the state of translation. Polysome profiles in different times of imbibition also reflect the movement of mRNAs during the germination process.

关 键 词： 植物细胞生理学 贮存信使核糖核酸 大豆胚根 种子萌发 转录抑制剂 鹅膏蕈碱 翻译抑制剂 放线菌酮 实时定量聚合酶链式反应 蔗糖密度梯度超速离心

领　　域： [生物学] [生物学]