淀粉质体遗传研究的现状与展望

Current Researches and Prospect of Amyloplast Inheritance

淀粉质体来源于前质体,与叶绿体同源,具有其特有的遗传特性,是核外遗传的重要组成部分。本文综述了淀粉质体遗传研究方面取得的成果和进展。淀粉质体DNA发现于20世纪70年代,其含量随着组织发育的不同阶段有所变化,最后这些DNA作为贮藏的形式积累在质体中。淀粉质体基因组与叶绿体基因组同源性很高,但是不表达与光合作用有关的基因。现有的实验证据表明,淀粉质体基因组的表达调控发生在转录水平,与DNA甲基化有关。淀粉质体的发育受核基因组和质体基因组双重调控。组织发育到一定时期,淀粉质体中出现单核糖体和多聚核糖体;淀粉质体具有蛋白质合成体系。淀粉质体DNA及淀粉质体遗传的研究具有重要的理论和实际意义,对淀粉质体遗传进行深入的研究,将丰富核外遗传知识和理论。

Amyloplast, originating from proplastid, is a kind of semi-autonomous organelle. Despite its homology to chloroplast, amyloplast possesses distinct characteristics as to genetics, which are important content in extranuclear inheritance. In this article, some aspects of genetical reseaches about amyloplast were summerized. It was in 1970s that researchers discovered DNA existing in amyloplasts. The DNA content of amyloplasts will fluctuate with developing, and then DNA stores in amyloplasts. Amyloplast genome exhibits high homology to chloroplast＇s, but there are no photosynthesis genes expressing in amyloplast. Available evidences proved DNA methylation as a mechanism of transcriptional regulation in amyloplasts. Further more, ribosomes and poly-ribosomes can be observed at certain stage during the development of the tissue. Finally, a system of protein synthesis functions in amyloplast. In general, the development of amyloplast is controled both by nucleic genome and plastid genome. In contrast to the lack in knowledge of amyloplast inheritance, it is not only of vitally theoretic significance but also of practical significance to study the inheritant characteristics of amyloplast. Further research works in this area can provide advanced insight into amyloplast inheritance.