Role of Peroxiporins in Plant Stress Signaling and Development

Reactive oxygen species (ROS) are omnipresent and surprisingly not integrated into biological systems. Initially, ROS were merely considered as by-products of aerobic metabolism; however, they have emerged as conserved regulators of physiological and developmental processes in all kingdoms of life. Among ROS, hydrogen peroxide (H₂O₂) plays a fundamental role in cell signaling and provides oxidative capacity to the endoplasmic reticulum (ER) and the apoplast for normal cellular functioning. H₂O₂ can cross biological membranes through specialized aquaporins, called peroxiporins. Although the role of peroxiporins in H₂O₂ transport and signaling is well documented (e.g., yeast, mammals), still little is known about their role in plants. In this chapter, we provide an overview and a perspective on the role of peroxiporins in plant development and their contribution to rapid systemic stress signaling by the ROS wave during abiotic stress. Finally, we highlight a few key open questions in the field of peroxiporins in plants.