Allelign Ashagre Hewot, Zaltzman David, Idan-Molakandov Anat, Romano Hila, Tzfadia Oren, Harpaz-Saad Smadar
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Jerusalem, Israel.
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Institute for Tropical Medicine, Antwerp, Belgium.
Front Plant Sci. 2021 Apr 7;12:645286. doi: 10.3389/fpls.2021.645286. eCollection 2021.
The plasticity of root development represents a key trait that enables plants to adapt to diverse environmental cues. The pattern of cell wall deposition, alongside other parameters, affects the extent, and direction of root growth. In this study, we report that FASCICLIN-LIKE ARABINOGALACTAN PROTEIN 18 (FLA18) plays a role during root elongation in . Using root-specific co-expression analysis, we identified to be co-expressed with a sub-set of genes required for root elongation. encodes for a putative extra-cellular arabinogalactan protein from the -gene family. Two independent T-DNA insertion lines, named and , display short and swollen lateral roots (LRs) when grown on sensitizing condition of high-sucrose containing medium. Unlike (), previously shown to display short and swollen primary root (PR) and LRs under these conditions, the PR of the mutants is slightly longer compared to the wild-type. Overexpression of the CDS complemented the root phenotype. Genetic interaction between either of the alleles and reveals a more severe perturbation of anisotropic growth in both PR and LRs, as compared to the single mutants and the wild-type under restrictive conditions of high sucrose or high-salt containing medium. Additionally, under salt-stress conditions, had a small, chlorotic shoot phenotype, that was not observed in any of the single mutants or the wild type. As previously shown for , the and root-elongation phenotype is suppressed by abscisic acid (ABA) and display hypersensitivity to the ABA synthesis inhibitor, Fluridon. Last, similar to other cell wall mutants, root elongation is hypersensitive to the cellulose synthase inhibitor, Isoxaben. Altogether, the presented data assign a new role for FLA18 in the regulation of root elongation. Future studies of the unique vs. redundant roles of FLA proteins during root elongation is anticipated to shed a new light on the regulation of root architecture during plant adaptation to different growth conditions.
根系发育的可塑性是使植物能够适应各种环境线索的关键特性。细胞壁沉积模式以及其他参数会影响根系生长的程度和方向。在本研究中，我们报告类成束蛋白阿拉伯半乳聚糖蛋白18（FLA18）在[具体植物名称未给出]的根伸长过程中发挥作用。通过根特异性共表达分析，我们确定[具体基因名称未给出]与根伸长所需的一组基因共同表达。[具体基因名称未给出]编码一种来自[具体基因家族名称未给出]基因家族的假定细胞外阿拉伯半乳聚糖蛋白。两个独立的T-DNA插入系，命名为[具体插入系名称1未给出]和[具体插入系名称2未给出]，在含有高蔗糖的敏感培养基上生长时，侧根（LRs）短且肿胀。与[之前提到的某个突变体未给出具体名称]不同，之前显示在这些条件下主根（PR）和侧根短且肿胀，[具体插入系名称1未给出]和[具体插入系名称2未给出]突变体的主根与野生型相比略长。[具体基因名称未给出]的CDS过表达补充了[具体插入系名称1未给出]和[具体插入系名称2未给出]的根表型。在含有高蔗糖或高盐的限制性培养基条件下，与单突变体和野生型相比，[具体插入系名称1未给出]或[具体插入系名称2未给出]的任何一个等位基因与[具体基因名称未给出]之间的遗传相互作用揭示了主根和侧根中各向异性生长的更严重扰动。此外，在盐胁迫条件下[具体插入系名称1未给出]和[具体插入系名称2未给出]有小的、黄化的地上部表型，这在任何单突变体或野生型中都未观察到。如之前对[具体突变体未给出具体名称]所示，[具体插入系名称1未给出]和[具体插入系名称2未给出]的根伸长表型被脱落酸（ABA）抑制，并且对ABA合成抑制剂氟啶酮表现出超敏感性。最后，与其他细胞壁突变体类似，[具体插入系名称1未给出]和[具体插入系名称2未给出]的根伸长对纤维素合酶抑制剂异恶草酮超敏感。总之，所呈现的数据赋予了FLA18在根伸长调节中的新作用。预计未来对FLA蛋白在根伸长过程中独特与冗余作用的研究将为植物适应不同生长条件下根系结构的调节提供新的见解。
