Department of Conservative Plant Biology, Polish Academy of Sciences Botanical Garden-Center for Biological Diversity Conservation in Powsin, Prawdziwka 2, Warsaw 02-973, Poland.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland.
Plant Cell Physiol. 2020 Jul 1;61(7):1273-1284. doi: 10.1093/pcp/pcaa058.
In this report, we describe studies on symplasmic communication and cellular rearrangement during direct somatic embryogenesis (SE) in the tree fern Cyathea delgadii. We analyzed changes in the symplasmic transport of low-molecular-weight fluorochromes, such as 8-hydroxypyrene-1,3,6-trisulfonic acid, trisodium salt (HPTS) and fluorescein (delivered to cells as fluorescein diacetate, FDA), within stipe explants and somatic embryos originating from single epidermal cells and developing during 16-d long culture. Induction of SE is preceded by a restriction in fluorochrome distribution between certain explant cells. Microscopic analysis showed a series of cellular changes like a decrease in vacuole size, increase in vacuole numbers, and increased density of cytoplasm and deposition of electron-dense material in cell walls that may be related with embryogenic transition. In somatic embryos, the limited symplasmic communication between cells was observed first in linear tri-cellular embryos. Further development of the fern embryo was associated with the formation of symplasmic domains corresponding to the four segments of the plant body. Using symplasmic tracers, we provided evidence that the changes in plasmodesmata permeability are corelated with somatic-to-embryogenic transition and somatic embryo development.
在本报告中，我们描述了树蕨桫椤（Cyathea delgadii）直接体细胞胚胎发生（SE）过程中胞质流和细胞重排的研究。我们分析了低分子量荧光染料如 8-羟基芘-1,3,6-三磺酸三钠盐（HPTS）和荧光素（作为荧光素二乙酸酯，FDA 递送到细胞内）在茎段外植体和起源于单个表皮细胞并在 16 天长的培养过程中发育的体细胞胚胎中的共质体运输变化。SE 的诱导之前是在某些外植体细胞之间的荧光染料分布受到限制。显微镜分析显示了一系列细胞变化，如液泡大小减小、液泡数量增加、细胞质密度增加和细胞壁中电子致密物质沉积，这些可能与胚胎发生转变有关。在体细胞胚胎中，首先在线性三细胞胚胎中观察到细胞之间有限的胞质流。蕨类植物胚胎的进一步发育与形成与植物体四个部分相对应的共质体域有关。使用共质体示踪剂，我们提供了证据表明胞间连丝通透性的变化与体细胞到胚胎发生的转变和体细胞胚胎发育有关。
