title: The symbiosis with the arbuscular mycorrhizal fungus Rhizophagus irregularis drives root water transport in flooded tomato plants.
abstract: It is known that the presence of arbuscular mycorrhizal fungi within the plant roots enhances the tolerance of the host plant to different environmental stresses, although the positive effect of the fungi in plants under waterlogged conditions has not been well studied. Tolerance of plants to flooding can be achieved through different molecular, physiological and anatomical adaptations, which will affect their water uptake capacity and therefore their root hydraulic properties. Here, we investigated the root hydraulic properties under non-flooded and flooded conditions in non-mycorrhizal tomato plants and plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. Only flooded mycorrhizal plants increased their root hydraulic conductivity, and this effect was correlated with a higher expression of the plant aquaporin SlPIP1;7 and the fungal aquaporin GintAQP1. There was also a higher abundance of the PIP2 protein phoshorylated at Ser280 in mycorrhizal flooded plants. The role of plant hormones (ethylene, ABA and IAA) in root hydraulic properties was also taken into consideration, and it was concluded that, in mycorrhizal flooded plants, ethylene has a secondary role regulating root hydraulic conductivity whereas IAA may be the key hormone that allows the enhancement of root hydraulic conductivity in mycorrhizal plants under low oxygen conditions.
authors.affiliation: Estación Experimental del Zaidín (CSIC), Department of Soil Microbiology and Symbiotic Systems, C/Profesor Albareda 1, 18008 Granada, Spain.
authors.forename: Monica
authors.initials: M
authors.lastname: Calvo-Polanco
authors.forename: Sonia
authors.initials: S
authors.lastname: Molina
authors.forename: Angel María
authors.initials: AM
authors.lastname: Zamarreño
authors.forename: Jose María
authors.initials: JM
authors.lastname: García-Mina
authors.forename: Ricardo
authors.initials: R
authors.lastname: Aroca
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D005030:Ethylenes / Q000378:metabolism; D055868:Floods; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D018506:Gene Expression Regulation, Plant; D055137:Glomeromycota / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D054884:Host-Pathogen Interactions; D007210:Indoleacetic Acids / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012694:Serine / Q000378:metabolism; D013559:Symbiosis; D014867:Water / Q000378:metabolism*
chemical_list: D020346:Aquaporins; D005030:Ethylenes; D005656:Fungal Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014867:Water; D012694:Serine; C030737:indoleacetic acid; D000040:Abscisic Acid; C036216:ethylene
keywords: Aquaporins; Arbuscular mycorrhizal fungi; Ethylene; IAA; Phosphorylation; Root hydraulic conductivity