Grira Maroua, Prinsen Els, Werbrouck Stefaan P O
Laboratory for Applied In Vitro Plant Biotechnology, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium.
Integrated Molecular Plant Physiology Research, Dement of Biology, University of Antwerp, Groenenborgerlaan 170, 2020 Antwerp, Belgium.
Plants (Basel). 2023 Oct 15;12(20):3577. doi: 10.3390/plants12203577.
An important factor affecting the uniformity of in vitro cultures is the topophysical position of the original explant. We investigated this phenomenon in , a tropical woody tree species. Shoots from a stock culture were separated into upper, middle and basal sections and transferred to a modified MS medium containing meta-topolin-riboside and indole-butyric acid. After 8 weeks, the middle section produced the most shoots, the longest shoots and the highest number of nodes per plant. Shoots derived from the upper section were elongated, but had the shortest internodes, while those from the basal section formed the largest callus. None of the three types of explants rooted during the proliferation phase. The topophysically dependent spatial distribution of endogenous cytokinins and auxins was determined. The topophysical effect observed could not be explained solely by analyzing the endogenous isoprenoid and auxin. However, the metabolism and distribution of the aromatic cytokinin could provide an explanation. The concentration of the meta hydroxy-substituted topolins was highest in shoots derived from the middle section. Aromatic N- and O-glucosides were much more concentrated in the leaves than in the stems. In conclusion, it is recommended to consider the explant's topophysis when developing a multiplication protocol to avoid heterogeneity in an in vitro culture.
影响体外培养均匀性的一个重要因素是原始外植体的顶部位置。我们在一种热带木本树种中研究了这一现象。将母株培养的芽分为上部、中部和基部切段，并转移到含有间-拓扑替康-核糖苷和吲哚丁酸的改良MS培养基中。8周后，中部切段产生的芽最多、芽最长且每株植物的节数最多。上部切段产生的芽伸长了，但节间最短，而基部切段产生的愈伤组织最大。在增殖阶段，这三种类型的外植体均未生根。确定了内源性细胞分裂素和生长素的顶部位置依赖性空间分布。仅通过分析内源性类异戊二烯和生长素无法解释观察到的顶部位置效应。然而，芳香族细胞分裂素的代谢和分布可以提供一种解释。间位羟基取代的拓扑替康在中部切段产生的芽中浓度最高。芳香族N-和O-糖苷在叶片中的浓度比在茎中高得多。总之，建议在制定增殖方案时考虑外植体的顶部位置，以避免体外培养中的异质性。
