Diving into the Water: Amphibious Plants as a Model for Investigating Plant Adaptations to Aquatic Environments
Hiroyuki Koga, Shuka Ikematsu, Seisuke Kimura
Abstract
Amphibious plants can grow and survive in both aquatic and terrestrial environments. This review explores the diverse adaptations that enable them to thrive in such contrasting habitats. Plants with amphibious lifestyles possess fascinating traits, and their phenotypic plasticity plays an important role in adaptations. Heterophylly, the ability to produce different leaf forms, is one such trait, with submerged leaves generally being longer, narrower, and thinner than aerial leaves. In addition to drastic changes in leaf contours, amphibious plants display significant anatomical and physiological changes, including a reduction in stomatal number and cuticle thickness and changes in photosynthesis mode. This review summarizes and compares the regulatory mechanisms and evolutionary origins of amphibious plants based on molecular biology studies actively conducted in recent years using novel model amphibious plant species. Studying amphibious plants will enhance our understanding of plant adaptations to aquatic environments.