Mokshina N, Gorshkov O, Ibragimova N, Pozhvanov G, Gorshkova T
a Kazan Institute of Biochemistry and Biophysics , FRC Kazan Scientific Center of RAS , Kazan , Russian Federation.
b Faculty of Biology, Department of Plant Physiology and Biochemistry , Saint Petersburg State University , Saint Petersburg , Russia.
Plant Signal Behav. 2018;13(6):e1486144. doi: 10.1080/15592324.2018.1486144. Epub 2018 Jul 3.
Flax phloem fibers act as constitutively formed "muscles" that support the vertical position of the high but narrow stem. The specific mechanical properties of flax fibers and of similar fibers in other plant species are provided by the development of tertiary cell wall with tensed cellulose microfibrils. The work of phloem fibers becomes especially pronounced during the restoration of stem vertical position if it was disturbed. Gravistimulation of flax plants induces considerable modification of phloem fibers at the pulling stem side - the lumen diameter increases, while the cell wall thickness goes down. Here we show that the action of phloem fibers as motors of stem vertical position restoration is coupled to the cell wall remodelling as well as the increase of osmolytes (mainly potassium and malate) content, and accumulation of the γ-amino-butyric acid that may be involved in signalling events. The molecular players that take part in these processes are suggested.
亚麻韧皮纤维起着固有形成的“肌肉”的作用，支撑着高而窄的茎的垂直位置。亚麻纤维以及其他植物物种中类似纤维的特定机械性能是由具有张紧的纤维素微纤丝的三生细胞壁的发育所赋予的。如果茎的垂直位置受到干扰，在其恢复过程中，韧皮纤维的作用就会特别明显。对亚麻植株进行重力刺激会导致茎拉伸侧的韧皮纤维发生显著变化——管腔直径增加，而细胞壁厚度减小。在这里，我们表明，韧皮纤维作为茎垂直位置恢复的动力，其作用与细胞壁重塑、渗透溶质（主要是钾和苹果酸）含量的增加以及γ-氨基丁酸的积累有关，γ-氨基丁酸可能参与信号转导事件。我们还提出了参与这些过程的分子参与者。
