Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria.
Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
Int J Mol Sci. 2021 Aug 26;22(17):9222. doi: 10.3390/ijms22179222.
Size control is a fundamental question in biology, showing incremental complexity in plants, whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Our results indicate that auxin-reliant growth programs affect the molecular complexity of xyloglucans, the major type of cell wall hemicellulose in eudicots. Auxin-dependent induction and repression of growth coincide with reduced and enhanced molecular complexity of xyloglucans, respectively. In agreement with a proposed function in growth control, genetic interference with xyloglucan side decorations distinctly modulates auxin-dependent differential growth rates. Our work proposes that auxin-dependent growth programs have a spatially defined effect on xyloglucan's molecular structure, which in turn affects cell wall mechanics and specifies differential, gravitropic hypocotyl growth.
大小控制是生物学中的一个基本问题，在植物中表现出递增的复杂性，植物细胞具有刚性细胞壁。植物激素生长素是一种重要的生长调节剂，对差异生长控制具有核心重要性。我们的结果表明，依赖生长素的生长程序会影响木葡聚糖的分子复杂性，木葡聚糖是双子叶植物细胞壁半纤维素的主要类型。生长素依赖性的诱导和抑制生长分别与木葡聚糖的分子复杂性降低和增强相对应。与在生长控制中提出的功能一致，木葡聚糖侧链修饰的遗传干扰明显调节生长素依赖性的差异生长速率。我们的工作表明，依赖生长素的生长程序对木葡聚糖的分子结构具有空间限定的影响，这反过来又影响细胞壁力学并指定差异的向地性下胚轴生长。
