花粉管通道法转基因技术的细胞胚胎学机理探讨

本文从细胞胚胎学出发,从理论上对花粉管通道、花粉管通道法的转化机理进行了研究。认为,外源DNA进入胚囊的途径,即外源DNA沿着连接柱头与胚囊的花粉管外界面渗入胚囊;外源DNA转化的受体应为合子;外源DNA转化的时期应限定在精卵融合至合子分裂前这一段时期,此时合子细胞壁尚未封闭;外源DNA转化受体的机制可能是外源DNA与处于原生质体状态的合子的随机融合。强调在应用此方法时,应对植物雌蕊结构以及受精经历的时间有全面了解,并列出了一些重要植物授粉后受精过程各阶段的时间,对外源DNA导入部位和方法提出了建议,并分析了花粉管通道法转基因技术转化率较低的原因。

Probing into Cytological Embryology Mechanism of Pollen-tube Pathway Transgenic Technology

From the angle of cytological embryology,the paper theoretically studies pollen-tube pathway and transgenic mechanism of pollen-tube pathway transgenic technology,holding that the pathway for exogenous DNA to enter into embryo sacs is that exogenous DNA through the interface connecting stigmas and embryo sacs;the receptors for transforming exogenous DNA is zygotes;the period of exogenous DNA transformation should be limited within the time between the fusing of sperms and eggs and the dividing of zygotes during which zygote cellwall has not completely formed;the receptor mechanism for exogenous DNA transformation probably is that exogenous DNA combines randomly with zygotes in plasmic state.It emphasizes that pistil structure and fertilization duration should be fully known in order that the technology can be put into use.In the meantime,it lists the times of various fertilization stages in some improtant plants after their pollination,puts forward some proposals about the methods and sites of DNA transformation as well as discussing the reasons why pollen-tube pathway transgenic technology has low transformation efficiency.