How Does pH Fit in with Oscillating Polar Growth?

MANGANO, SILVINA; MARTÍNEZ PACHECO, JAVIER; MARINO-BUSLJE, CRISTINA; ESTEVEZ, JOSÉ M.

TRENDS IN PLANT SCIENCE.

ELSEVIER SCIENCE LONDON

Año: 2018

1360-1385

Polar growth in root hairs and pollen tubes is an excellent model for investigating plant cell size regulation. While linear plant growth is historically explained by the acid growth theory, which considers that auxin triggers apoplastic acidification by activating plasma membrane P-type H+-ATPases (AHAs) along with cell wall relaxation over long periods, the apoplastic pH (apopH) regulatory mechanisms are unknown for polar growth. Polar growth is a fast process mediated by rapid oscillations that repeat every ~20-40 seconds. In this review, we explore a ROS-dependent mechanism that could generate oscillating apopH gradients in a coordinated manner with growth and Ca2+ oscillations. We hypothesize that apopH oscillations act as a central pacemaker that coordinates growth together with ROS and Ca2+.