Bush Max, Sethi Vishmita, Sablowski Robert
Cell and Developmental Biology Department, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.
Front Plant Sci. 2022 Apr 26;13:888201. doi: 10.3389/fpls.2022.888201. eCollection 2022.
The plant vasculature plays essential roles in the transport of water and nutrients and is composed of xylem and phloem, both of which originate from undifferentiated cells found in the cambium. Development of the different vascular tissues is coordinated by hormonal and peptide signals and culminates in extensive cell wall modifications. Pectins are key cell wall components that are modified during cell growth and differentiation, and pectin fragments function as signals in defence and cell wall integrity pathways, although their role as developmental signals remains tentative. Here, we show that the pectin lyase-like gene is required for growth of the vascular bundles in the Arabidopsis inflorescence stem. Although PLL12 was expressed primarily in the phloem, it also affected cambium and xylem growth. Surprisingly, PLL12 overexpression induced ectopic cambium and xylem differentiation in the inflorescence apex and inhibited development of the leaf vasculature. Our results raise the possibility that a cell wall-derived signal produced by in the phloem regulates cambium and xylem development.
植物维管系统在水分和养分运输中起着至关重要的作用，由木质部和韧皮部组成，二者均起源于形成层中未分化的细胞。不同维管组织的发育由激素和肽信号协调，并最终导致广泛的细胞壁修饰。果胶是在细胞生长和分化过程中发生修饰的关键细胞壁成分，果胶片段在防御和细胞壁完整性途径中发挥信号作用，尽管它们作为发育信号的作用仍不确定。在此，我们表明果胶裂解酶样基因对于拟南芥花序茎中维管束的生长是必需的。尽管PLL12主要在韧皮部表达，但它也影响形成层和木质部的生长。令人惊讶的是，PLL12过表达在花序顶端诱导异位形成层和木质部分化，并抑制叶片维管系统的发育。我们的结果提出了一种可能性，即韧皮部中由PLL12产生的细胞壁衍生信号调节形成层和木质部的发育。
