title: Exogenous ABA accentuates the differences in root hydraulic properties between mycorrhizal and non mycorrhizal maize plants through regulation of PIP aquaporins.
abstract: The arbuscular mycorrhizal (AM) symbiosis has been shown to modulate the same physiological processes as the phytohormone abscisic acid (ABA) and to improve plant tolerance to water deficit. The aim of the present research was to evaluate the combined influence of AM symbiosis and exogenous ABA application on plant root hydraulic properties and on plasma-membrane intrinsic proteins (PIP) aquaporin gene expression and protein accumulation after both a drought and a recovery period. Results obtained showed that the application of exogenous ABA enhanced osmotic root hydraulic conductivity (L) in all plants, regardless of water conditions, and that AM plants showed lower L values than nonAM plants, a difference that was especially accentuated when plants were supplied with exogenous ABA. This effect was clearly correlated with the accumulation pattern of the different PIPs analyzed, since most showed reduced expression and protein levels in AM plants fed with ABA as compared to their nonAM counterparts. The possible involvement of plant PIP aquaporins in the differential regulation of L by ABA in AM and nonAM plants is further discussed.
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Profesor Albareda no.1, Granada, Spain. juanmanuel.ruiz@eez.csic.es
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Ruiz-Lozano
authors.forename: Maria
authors.initials: M
authors.lastname: del Mar Alguacil
authors.forename: Gloria
authors.initials: G
authors.lastname: Bárzana
authors.forename: Paolo
authors.initials: P
authors.lastname: Vernieri
authors.forename: Ricardo
authors.initials: R
authors.lastname: Aroca
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology*; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D054884:Host-Pathogen Interactions; D038821:Mycorrhizae / Q000502:physiology*; D009997:Osmotic Pressure / Q000187:drug effects; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013559:Symbiosis / Q000502:physiology; D014867:Water / Q000378:metabolism; D003313:Zea mays / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology
chemical_list: D020346:Aquaporins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014867:Water; D000040:Abscisic Acid