BdERECTA controls vasculature patterning and phloem-xylem organization in Brachypodium distachyon

Abstract

Background The vascular system of plants consists of two main tissue types, xylem and phloem. These tissues are organized into vascular bundles that are arranged into a complex network running through the plant that is essential for the viability of land plants. Despite their obvious importance, the genes involved in the organization of vascular tissues remain poorly understood in grasses. Results We studied in detail the vascular network in stems from the model grass Brachypodium distachyon (Brachypodium) and identified a large set of genes differentially expressed in vascular bundles versus parenchyma tissues. To decipher the underlying molecular mechanisms of vascularization in grasses, we conducted a forward genetic screen for abnormal vasculature. We identified a mutation that severely affected the organization of vascular tissues. This mutant displayed defects in anastomosis of the vascular network and uncommon amphivasal vascular bundles. The causal mutation is a premature stop codon in ERECTA, a LRR receptor-like serine/threonine-protein kinase. Mutations in this gene are pleiotropic indicating that it serves multiple roles during plant development. This mutant also displayed changes in cell wall composition, gene expression and hormone homeostasis. Conclusion In summary, ERECTA has a pleiotropic role in Brachypodium. We propose a major role of ERECTA in vasculature anastomosis and vascular tissue organization in Brachypodium.

Suppression of Phytochrome-Interacting Factors Enhances Photoresponses of Seedlings and Delays Flowering With Increased Plant Height in Brachypodium distachyon

“…11 (Sigma-Aldrich), subjected to 0.02% toluidine blue staining for 30 s, and rinsed with distilled water. Stem diameter, the number of vascular bundles and pitch cells, and pitch cavity were then estimated, as previously described ( Matos et al, 2013 ; Sakai et al, 2021 ).…”

The wild grass Brachypodium distachyon as a developmental model system

“…Importantly, most of the work we will describe would not have been possible without the resources described above. There are a number of additional developmental processes being studied in B. distachyon; important contributions include for example, cell wall biology (see Coomey et al, 2020) and references therein), vascular development (Sakai et al, 2021;Smertenko et al, 2019), pleiotropic genes like the NOOT-BOP-COCH-LIKE genes (Magne et al, 2020), seed germination (Wolny et al, 2018), species-specific aspects of abscission zone formation (Yu et al, 2020), and even thigmomorphogenesis-the developmental response to touch (Coomey et al, 2021). We apologize for not being able to cover all the developmental work done with B. distachyon due to space limitations.…”

The Rapid-Tome, a 3D-Printed Microtome, and an Updated Hand-Sectioning Method for High-Quality Plant Sectioning

“…For example, over 20 years ago, the field of secondary cell wall synthesis was propelled by the identification of irregular xylem mutants through screening an Arabidopsis population via microscopic examination of stem sections [4]. More recently, a forward genetic screen of abnormal vasculature in cross sections of Brachypodium distachyon identified a mutant phenotype caused by a premature stop codon in BdERECTA that impacts regulation of vascular bundle development and may impact function [5]. In another recent example, laser ablation tomography (LAT) was applied to screen for root anatomy phenotypes in cross sections of a genome wide association panel of maize ( Zea mays) to identify multiseriate cortical sclerenchyma correlated with greater root tip lignin concentrations and bending strength [6].…”

“…More recently, a forward genetic screen of abnormal vasculature in cross sections of Brachypodium distachyon identified a mutant phenotype caused by a premature stop codon in BdERECTA that impacts regulation of vascular bundle development and may impact function [5].…”