DATE2026.02.18 #Press Releases
A Discovery that Overturns Conventional Understanding: An Amphibious Plant Differentiates Chloroplasts in Epidermal Cells in Response to Submergence — a Previously Unknown Phenomenon
-Revealing a Novel Environmental Response Mechanism Supporting Underwater Photosynthesis-
Summary
Chloroplasts are essential cellular organelles responsible for photosynthesis. In seed plants, they are primarily found in mesophyll cells inside the leaf and have generally been considered absent, or present only in very small numbers, in epidermal cells.
In this study, we discovered a previously unreported environmental response in the amphibious plant Rorippa aquatica, in which chloroplasts differentiate in epidermal cells in response to submergence.
The research team named this phenomenon Environmentally responsive Epidermal Chloroplast Differentiation (ECD). ECD is triggered by signals specific to underwater environments and is thought to facilitate photosynthesis by enabling the plant to use carbon dioxide that enters internal tissues through the epidermis under submerged conditions.
These findings not only reveal part of the mechanism by which plants adapt to aquatic environments but may also contribute to the future development of crops tolerant to flooding and waterlogging, as well as to a better understanding of plant survival strategies under climate change. This study was published in the international academic journal New Phytologist (dated February 18, 2026, JST).
Associate Professor Hiroyuki Koga (Department of Biological Sciences) participated in this research.
Figure：Mechanism of ECD
Links
Kyoto Sangyo University, Tokyo University of Science, Teikyo University
Journals
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Journal name New PhytologistTitle of paper