Quantification of Tracheary Elements Types in Mature Hypocotyl of Arabidopsis thaliana

Abstract

Secondary growth is a highly relevant process for dicot and gymnosperm species development. The process relies on vascular tissue proliferation and culminates with the thickening of stems, roots, and hypocotyls. The formation of tracheary elements is a critical step during this process. Among such tracheary elements, four different cell types are distinguished depending on their secondary cell wall pattern, which is exclusive for each tracheary cell type. Here we describe a method to isolate, dye, and recognize each of these tracheary cell types. The method is optimized to be performed in the Arabidopsis thaliana hypocotyl. This is because, in this species, the hypocotyl is the organ undergoing the largest proportion of secondary growth. Results allow for determining the relative amounts of each of the tracheary cell types.

Keywords: Arabidopsis thaliana; Hypocotyl; Secondary growth; Tracheary elements; Xylem.