Spatiotemporal relationship between auxin dynamics and hydathode development in Arabidopsis leaf teeth

Plant Signal Behav. 2021 Dec 2;16(12):1989216. doi: 10.1080/15592324.2021.1989216. Epub 2021 Oct 25.

Abstract

Hydathode is a plant tissue of vascular plants involved in water release called guttation. Arabidopsis hydathodes are found at the tips of leaf teeth and contain three major components: water pores, xylem ends, and small cells. Leaf teeth are known as the main parts for auxin biosynthesis and accumulation during leaf development. However, the detailed spatiotemporal relationship between auxin dynamics and hydathode development is unknown. In this study, we show that auxin biosynthesis and accumulation precede hydathode development. A triple marker line (called YDE line) containing three leaf tooth markers: YUC4:nls-3xGFP (auxin biosynthesis), DR5rev:erRFP (auxin accumulation or maxima), and E325-GFP (hydathode development), was generated, and spatiotemporal confocal microscopic analysis was carried out. The expression area of these markers became larger during leaf development, implying that the hydathode size enlarges as the leaf tooth grows. Detailed observation revealed that the auxin-related markers YUC4:nls-GFP and DR5rev:erRFP were first expressed in the early stage of leaf tooth growth. Then, E325-GFP was expressed partly overlapping with the auxin markers at a later stage. These findings provide new insights into the spatiotemporal relationship between auxin dynamics and hydathode development in Arabidopsis.

Keywords: Arabidopsis thaliana; DR5; YUC4; auxin; epithem; hydathode; leaf tooth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins* / genetics
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / metabolism
  • Gene Expression Regulation, Plant
  • Indoleacetic Acids / metabolism
  • Plant Leaves / metabolism
  • Xylem / metabolism

Substances

  • Arabidopsis Proteins
  • Indoleacetic Acids

Grants and funding

This work was supported by Grants-in-Aid for Scientific Research to K.T. [grant number; JP26711017 and JP18K06283] and to T.S. [grant number; JP18K06284] from the Japan Society for the Promotion of Science; by the Human Frontier Science Program to K.T. [RGP0009/2018] from the International Human Frontier Science Program Organization; and by the Sasakawa Scientific Research Grant from the Japan Science Society to H.Y.