多倍体化引起植物表型突变的分子机理研究

Molecular Mechanism for Phenotypic Mutation Arisen from Polyploidization in Plant

多倍体化后经常出现一些新的表型;但是,大量的表型变异发生的原因一直不清楚。最近人们对拟南芥菜、棉花、小麦、油菜等人工合成四倍体的研究,为理解这种表型变异的机制提供了线索。初步结果表明,无论同源多倍体还是异源多倍体化后,既有基因的甲基化也有基因的脱甲基化,某些甲基化状态的改变可以重复且独立发生。这些甲基化了的基因可以用azadC再激活。利用多倍体产生的甲基化突变体将有助于进一步研究这一过程的分子机制。本文讨论了利用同源四倍体水稻产生二倍体的基因缺失与沉默突变体的可能性。

Polyploidy can induce mutants with new phenotypes, but the molecular mechanism of mutation is poorly understood. Recent studies on artificial tetraploids of Arabidopsis, cotton, wheat, and canola have provided the way for understanding its mechanism. Preliminary results indicated that some gene silences due to DNA hypermethylation or hypomethylation were frequently caused by either autopolyploids or allopolyploids, and the hypermethylation genes could be reactivated by azadC, a demethylating agent. Further study on hypermethylation would be required for better understanding the mechanism of polyploidization. This paper also discussed the possibility to obtain hypermethylation mutant from autotetraploidy rice.