Pollen aquaporins: the solute factor

PEREZ JULIANA; GABRIELA SOTO; JORGE MUSCHIETTI; GABRIELA AMODEO

Frontiers in Plant Science

Frontiers

Lugar: Laussanne; Año: 2016

In the recent years, the biophysical properties and presumed physiological role ofaquaporins (AQPs) have been expanded to specialized cells where water and soluteexchange are crucial traits. Complex but unique processes such as stomatal movementor pollen hydration and germination have been addressed not only by identifying thespecific AQP involved but also by studying how these proteins integrate and coordinatecellular activities and functions. In this review, we referred specifically to pollen-specificAQPs and analyzed what has been assumed in terms of transport properties and whathas been found in terms of their physiological role. Unlike that in many other cells, theAQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which areextensively studied for their high water capacity exchange. Instead, a variety of TIPs andNIPs are expressed in pollen. These findings have altered the initial understanding ofAQPs and water exchange to consider specific and diverse solutes that might be criticalto sustaining pollen?s success. The spatial and temporal distribution of the pollen AQPsalso reflects a regulatory mechanism that allowing a properly adjusting water and soluteexchange.