Aquaporins and the soil-plant-atmosphere continuum: are there new challenges?

PABLO CÁCERES; CARLOS MANACORDA; MOIRA SUTKA; VICTORIA VITALI; SEBASTIÁN ASURMENDI; IRENE BAROLI; GABRIELA AMODEO

Pucón

Congreso; LXV Reunión anual de la Sociedad de Biología de Chile; 2022

Decades ago, the role of water potential gradients was established as critical in driving downhill water flows from the soil to the plant root-shoot system to reach a water-demanding atmosphere. Through this continuum, the major hydraulic resistances can be arranged in analogy to an electrical circuit. At the shoot level, stomatal conductance tightly regulates the water exchange. On the other hand, to understand how the root system is regulated we still need to integrate recent advances at the molecular level -particularly regarding aquaporins- to assess if changes in membrane water permeability on the cell-to-cell pathway have a major impact on root hydraulic conductivity. Aquaporins are highly regulated transmembrane proteins that share common structural features regardless of their multiple isoforms, high diversity in cell localization and transport selectivity. Some members of this protein family account for high water transport capacity. Our working hypothesis is that the root cell-to-cell pathway can be a strong modulator of the plant hydraulic dynamics. Our results show that plant root hydraulic adjustment is favored if the cell-to-cell pathway is highly regulated for water exchange. This is relevant not only for the plant hydraulic dynamics but also can be demonstrated that improves the short-term response to adverse plant environmental conditions.