Global Change Research Institute, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
Brno University of Technology, Faculty of Mechanical Engineering, Brno, Czech Republic.
Mol Biol Rep. 2024 Mar 23;51(1):444. doi: 10.1007/s11033-024-09392-x.
2,4-D is a broadly used auxin herbicide. The presence of the 2,4-D synthetic auxin in the medium is imperative for long-term BY-2 tobacco suspension viability. The precise mechanism of this symbiosis of the suspension and the synthetic auxin remains unclear. Our goal was to study the hormonal regulation of the growth of the cell suspension; and to describe the experiments clarifying the interaction between the chosen growth regulators and phytohormones on the cellular level, specifically between the 2,4-D synthetic auxin and the native stress phytohormone - ethylene. This study examined the influence of low 2,4-D concentrations stimulating cell growth in vitro as well as the influence of high herbicide concentrations on the model tobacco BY-2 suspension. The culture took 6 days. Different parameters were evaluated, including the influence of different 2,4-D concentrations on the production of the phytohormone ethylene and its precursor 1-Aminocyclopropane-1-carboxylic acid (ACC) in the tobacco cells. The content of 2,4-D in the cells and the medium was established. The observations of the morphological changes showed that a heavy impregnation of the cell walls taking place depending on the concentration of 2,4-D. A dramatic increase in protective polysaccharides and a remodulation of the cell walls by the formation of a pectin shield in artificial conditions were expected and observed. At the same time, massive production of the stress phytohormone ethylene took place, and, because of that, plant mutagenicity, anomalous tumour-type proliferation growth, and the production of supercells were observed. The hypothesis of the protective shield is discussed.
2,4-D 是一种广泛使用的生长素除草剂。培养基中 2,4-D 合成生长素的存在对于长期 BY-2 烟草悬浮细胞活力是必不可少的。这种悬浮液和合成生长素共生的确切机制尚不清楚。我们的目标是研究细胞悬浮液生长的激素调节；并描述澄清所选生长调节剂与植物激素之间相互作用的实验，特别是在合成生长素 2,4-D 和天然应激植物激素 - 乙烯之间的相互作用，在细胞水平上。这项研究考察了低浓度 2,4-D 刺激体外细胞生长的影响，以及高除草剂浓度对模型烟草 BY-2 悬浮液的影响。培养进行了 6 天。评估了不同的参数，包括不同 2,4-D 浓度对烟草细胞中植物激素乙烯及其前体 1-氨基环丙烷-1-羧酸（ACC）产生的影响。建立了细胞和培养基中 2,4-D 的含量。观察细胞壁的形态变化表明，根据 2,4-D 的浓度，细胞壁发生了严重的浸渍。预计并观察到在人工条件下，保护性多糖大量产生，细胞壁通过形成果胶屏蔽进行重塑。同时，大量应激植物激素乙烯的产生导致植物诱变、异常肿瘤样增殖生长和超细胞的产生。讨论了保护性屏蔽的假说。
